Cancer Prevalence in Children with Inborn Errors of Immunity: Report from a Single Institution.

BACKGROUND: Inborn Errors of Immunity (IEI) comprise several genetic anomalies that affect different components of the innate and adaptive responses, predisposing to infectious diseases, autoimmunity and malignancy. Different studies, mostly in adults, have reported a higher prevalence of cancer in IEI patients. However, in part due to the rarity of most of these IEI subtypes (classified in ten categories by the Primary Immunodeficiency Committee of the International Union of Immunological Societies), it is difficult to assess the risk in a large number of patients, especially during childhood. OBJECTIVE: To document the cancer prevalence in a pediatric cohort from a single referral institution, assessing their risk, together with the type of neoplasia within each IEI subgroup. METHOD: An extensive review of clinical records from 1989 to 2022 of IEI patients who at some point developed cancer before the age of sixteen. RESULTS: Of a total of 1642 patients with IEI diagnosis, 34 developed cancer before 16 years of age, showing a prevalence (2.1%) significantly higher than that of the general age matched population (0.22). Hematologic neoplasms (mostly lymphomas) were the most frequent malignancies. CONCLUSION: This study represents one of the few reports focused exclusively in pediatric IEI cases, describing not only the increased risk of developing malignancy compared with the age matched general population (a fact that must be taken into account by immunologists during follow-up) but also the association of the different neoplasms with particular IEI subtypes, thus disclosing the possible mechanisms involved.

Impact of IKZF1 Deletions in the Prognosis of Childhood Acute Lymphoblastic Leukemia in Argentina.

An association of deletions in the IKZF1 gene (IKZF1del) with poor prognosis in acute lymphoblastic leukemia (ALL) has been demonstrated. Additional deletions in other genes (IKZF1plus) define different IKZF1del subsets. We analyzed the influence of IKZF1del and/or IKZF1plus in the survival of children with ALL. From October 2009 to July 2021, 1055 bone marrow samples from patients with ALL were processed by Multiplex ligation-dependent probe amplification (MLPA). Of them, 28 patients died during induction and 4 were lost-in-follow-up, resulting in an eligible 1023 cases. All patients were treated according to ALLIC-BFM-2009-protocol. Patients were classified into three subsets: IKZF1not-deleted (IKZFF1not-del), IKZF1deleted (IKZF1del) and IKZF1del plus deletion of PAX5, CDKN2A, CDKN2B and/or alterations in CRLF2 with ERG-not-deleted (IKZF1plus). The LFSp and SE were calculated with the Kaplan−Meier calculation and compared with a log-rank test. From the 1023 eligible patients, 835 (81.6%) were defined as IKZF1not-del, 94 (9.2%) as IKZF1del and 94 (9.2%) as IKZF1plus. Of them, 100 (9.8%) corresponded to Standard-Risk (SRG), 629 (61.5%) to Intermediate-Risk (IRG) and 294 (28.7%) to High-Risk (HRG) groups. LFSp(SE) was 7 5(2)% for IKZF1not-del, 51 (6)% for IKZF1del and 48 (6)% for IKZF1plus (p-value < 0.00001). LFSp(SE) according to the risk groups was: in SRG, 91 (4)% for IKZF1not-del, 50 (35)% IKZF1del and 100% IKZF1plus (p-value = ns); in IRG, 77 (2)% IKZF1not-del, 61 (10)% IKZF1del and 54 (7)% IKZF1plus (p-value = 0.0005) and in HRG, 61 (4)% IKZF1not-del, 38 (8)% IKZF1del and 35 (9)% IKZF1plus (p-value = 0.0102). The IKZF1 status defines a population of patients with a poor outcome, mainly in IRG. No differences were observed between IKZF1del versus IKZF1plus. MLPA studies should be incorporated into the risk-group stratification of pediatric ALL.

Clonal Myeloproliferative Disorders in Patients with Down Syndrome-Treatment and Outcome Results from an Institution in Argentina.

Children with Down syndrome (DS) are at an increased risk of developing clonal myeloproliferative disorders. The balance between treatment intensity and treatment-related toxicity has not yet been defined. We analyzed this population to identify risk factors and optimal treatment. This single-center retrospective study included 78 DS patients <16 years-old with Transient Abnormal Myelopoiesis (TAM, n = 25), Acute Myeloblastic Leukemia (DS-AML, n = 41) of which 35 had classical Myeloid Leukemia associated with DS (ML-DS) with megakaryoblastic immunophenotype (AMKL) and 6 sporadic DS-AML (non-AMKL). Patients with DS-AML were treated according to four BFM-based protocols. Classical ML-DS vs. non-DS-AMKL were compared and the outcome of ML-DS was analyzed according to treatment intensity. Only four patients with TAM required cytoreduction with a 5-year Event-Free Survival probability (EFSp) of 74.4 (±9.1)%. DS-AML treatment-related deaths were due to infections, with a 5-year EFSp of 60.6 (±8.2)%. Megakaryoblastic immunophenotype was the strongest good-prognostic factor in univariate and multivariate analysis (p = 0.000). When compared ML-DS with non-DS-AMKL, a better outcome was associated with a lower relapse rate (p = 0.0002). Analysis of administered treatment was done on 32/33 ML-DS patients who achieved CR according to receiving or not high-dose ARA-C block (HDARA-C), and no difference in 5-year EFSp was observed (p = 0.172). TAM rarely required treatment and when severe manifestations occurred, early intervention was effective. DS-AML good outcome was associated with AMKL with a low relapse-rate. Even if treatment-related mortality is still high, our data do not support the omission of HDARA-C in ML-DS since we observed a trend to detect a higher relapse rate in the arm without HDARA-C.

[Measurable residual disease by rearrangements of immunoglobulins and T-lymphocyte receptors]. / Enfermedad residual medible mediante reordenamientos de inmunoglobulinas y receptores de linfocitos-T.

Acute leukemias are the most common neoplasm in pediatric patients. Currently, 80% of children with diagnosis of acute lymphoblastic leukemia (ALL) are cured with conventional chemotherapy, but 20% of them will have a recurrence of the disease. Measurable Residual Disease (MRD) has been described as an important prognostic factor that allows evaluating the response of patients to treatment. One of the most sensitive techniques to study MRD is the quantification of immunoglobulins (Ig) and T-lymphocyte receptors (TCR) genes rearrangements. The aims of this study were to describe the detected Ig/TCR rearrangements, to evaluate the prognostic impact of MRD in our population of children with ALL and to compare the MRD values by Ig/TCR with those obtained by multiparametric flow cytometry (MFC). A total of 455 patients were studied. In 96% of the cases, it was possible to characterize at least one Ig/TCR rearrangement. The total number of Ig/TCR rearrangements detected was 1550. MRD was successfully applied in 89% of the cases. The combined positive MRD values at day 33 and 78 of treatment allow the identification of high-risk patients in cases previously stratified by MRD using flow cytometry at day 15. The comparison between MRD determination by Ig/TCR rearrangements and FC showed excellent correlation. The present work constitutes a study of MRD by Ig/TCR carried out in a very significant number of patients consecutively diagnosed, treated within a homogeneous protocol and with excellent clinical follow-up.

Las leucemias agudas constituyen la neoplasia más frecuente en pacientes pediátricos. Actualmente, el 80% de los niños con leucemia linfoblástica aguda (LLA) logran curarse con quimioterapia convencional pero el 20% de los mismos presentarán una reaparición de la enfermedad. La enfermedad residual medible (ERM) ha sido descripta como un importante factor pronóstico, que permite evaluar la respuesta de los pacientes al tratamiento. Una de las técnicas más sensibles par a estudiar ERM es la cuantificación de reordenamientos génicos de inmunoglobulinas (Ig) y receptores de linfocitos-T (TCR). Los objetivos del presente trabajo fueron describir los reordenamientos detectados de Ig/TCR, evaluar el efecto de la ERM en la supervivencia de niños con LLA y comparar la ERM por Ig/TCR con la cuantificada mediante citometría de flujo multiparamétrica (CFM). Del total de 455 pacientes estudiados, en el 96% fue posible caracterizar al menos un reordenamiento de Ig/TCR. El total de reordenamientos clonales detectados fue de 1550. La ERM pudo ser estudiada en forma exitosa en el 89% de los casos. El valor de ERM positiva combinada al día 33 y 78 de tratamiento, permitió identificar pacientes de alto riesgo, entre los previamente estratificados por la ERM mediante CFM al día 15. La comparación entre la determinación de ERM mediante reordenamientos Ig/TCR y CFM mostró una excelente correlación. El presente trabajo constituye un estudio de ERM mediante Ig/TCR realizado en un número muy significativo de pacientes diagnosticados en forma consecutiva, tratados en el marco de un protocolo homogéneo y con excelente seguimiento clínico.

Síndrome hipotalámico como presentación inusual de recaída en el sistema nervioso central de leucemia linfoblástica aguda en niños: reporte de 4 casos / Hypothalamic syndrome as an unusual presentation of CNS relapse of acute lymphoblastic leukemia in children: report of 4 cases

La leucemia linfoblástica aguda (LLA) es la patología oncológica más frecuente en pediatría, y corresponde al 23% de las neoplasias en menores de 15 años. Alrededor del 20% de los pacientes con LLA presentan recaídas, en la mayoría de los casos, en la médula ósea. Las recaídas extramedulares son inusuales y las dos localizaciones más frecuentes son el sistema nervioso central (SNC) y los testículos. Cuando las recaídas ocurren en el SNC, suelen manifestarse con un síndrome meníngeo. El síndrome hipotalámico se define como la presencia de hiperfagia, obesidad y/o cambios en el estado de ánimo, y es una forma de presentación clínica inusual de las recaídas en el SNC y debe alertar al pediatra para mantener un alto índice de sospecha.Se describen cuatro casos que se presentaron con síndrome hipotalámico al momento de desarrollar una recaída de LLA en el SNC

Acute lymphoblastic leukemia (ALL) is the most common malignancy in childhood, corresponding to 23% of cancer in children younger than 15 years old. About 20% of ALL cases will relapse, commonly in the bone marrow. Extramedullar relapses are unusual, and the two most frequent locations are CNS and testicles. ALL relapses, when diagnosed in the CNS, frequently present with clinical features of a meningeal syndrome. The hypothalamic syndrome, consisting of hyperphagia, obesity and / or behavior disturbances, corresponds to an unusual presentation of relapses in this location and should alert pediatricians to suspect it.We describe 4 ALL cases of hypothalamic syndrome at the time of CNS relapse

Enfermedad residual medible mediante reordenamientos de inmunoglobulinas y receptores de linfocitos-T / Measurable residual disease by rearrangements of immunoglobulins and T-lymphocyte receptors

Resumen Las leucemias agudas constituyen la neoplasia más frecuente en pacientes pediátricos. Actualmente, el 80% de los niños con leucemia linfoblástica aguda (LLA) logran curarse con quimioterapia con vencional pero el 20% de los mismos presentarán una reaparición de la enfermedad. La enfermedad residual medible (ERM) ha sido descripta como un importante factor pronóstico, que permite evaluar la respuesta de los pacientes al tratamiento. Una de las técnicas más sensibles par a estudiar ERM es la cuantificación de reordena mientos génicos de inmunoglobulinas (Ig) y receptores de linfocitos-T (TCR). Los objetivos del presente trabajo fueron describir los reordenamientos detectados de Ig/TCR, evaluar el efecto de la ERM en la supervivencia de niños con LLA y comparar la ERM por Ig/TCR con la cuantificada mediante citometría de flujo multiparamétrica (CFM). Del total de 455 pacientes estudiados, en el 96% fue posible caracterizar al menos un reordenamiento de Ig/TCR. El total de reordenamientos clonales detectados fue de 1550. La ERM pudo ser estudiada en forma exitosa en el 89% de los casos. El valor de ERM positiva combinada al día 33 y 78 de tratamiento, permitió identificar pacientes de alto riesgo, entre los previamente estratificados por la ERM mediante CFM al día 15. La comparación entre la determinación de ERM mediante reordenamientos Ig/TCR y CFM mostró una excelente correlación. El presente trabajo constituye un estudio de ERM mediante Ig/TCR realizado en un número muy significativo de pacientes diagnosticados en forma consecutiva, tratados en el marco de un protocolo homogéneo y con excelente seguimiento clínico.

Abstract Acute leukemias are the most common neoplasm in pediatric patients. Currently, 80% of children with diagnosis of acute lymphoblastic leukemia (ALL) are cured with conventional chemotherapy, but 20% of them will have a recurrence of the disease. Measurable Residual Disease (MRD) has been described as an important prognostic factor that allows evaluating the response of patients to treatment. One of the most sensitive techniques to study MRD is the quantification of immunoglobulins (Ig) and T-lymphocyte receptors (TCR) genes rearrangements. The aims of this study were to describe the detected Ig/TCR rearrangements, to evaluate the prognostic impact of MRD in our population of children with ALL and to compare the MRD values by Ig/TCR with those obtained by multiparametric flow cytometry (MFC). A total of 455 patients were studied. In 96% of the cases, it was possible to characterize at least one Ig/TCR rearrangement. The total number of Ig/TCR rear rangements detected was 1550. MRD was successfully applied in 89% of the cases. The combined positive MRD values at day 33 and 78 of treatment allow the identification of high-risk patients in cases previously stratified by MRD using flow cytometry at day 15. The comparison between MRD determination by Ig/TCR rearrangements and FC showed excellent correlation. The present work constitutes a study of MRD by Ig/TCR carried out in a very significant number of patients consecutively diagnosed, treated within a homogeneous protocol and with excellent clinical follow-up.

[Hypothalamic syndrome as an unusual presentation of CNS relapse of acute lymphoblastic leukemia in children: report of 4 cases]. / Síndrome hipotalámico como presentación inusual de recaída en el sistema nervioso central de leucemia linfoblástica aguda en niños: reporte de 4 casos.

Acute lymphoblastic leukemia (ALL) is the most common malignancy in childhood, corresponding to 23 % of cancer in children younger than 15 years old. About 20 % of ALL cases will relapse, commonly in the bone marrow. Extramedullar relapses are unusual, and the two most frequent locations are CNS and testicles. ALL relapses, when diagnosed in the CNS, frequently present with clinical features of a meningeal syndrome. The hypothalamic syndrome, consisting of hyperphagia, obesity and / or behavior disturbances, corresponds to an unusual presentation of relapses in this location and should alert pediatricians to suspect it. We describe 4 ALL cases of hypothalamic syndrome at the time of CNS relapse.

La leucemia linfoblástica aguda (LLA) es la patología oncológica más frecuente en pediatría, y corresponde al 23 % de las neoplasias en menores de 15 años. Alrededor del 20 % de los pacientes con LLA presentan recaídas, en la mayoría de los casos, en la médula ósea. Las recaídas extramedulares son inusuales y las dos localizaciones más frecuentes son el sistema nervioso central (SNC) y los testículos. Cuando las recaídas ocurren en el SNC, suelen manifestarse con un síndrome meníngeo. El síndrome hipotalámico se define como la presencia de hiperfagia, obesidad y/o cambios en el estado de ánimo, y es una forma de presentación clínica inusual de las recaídas en el SNC y debe alertar al pediatra para mantener un alto índice de sospecha. Se describen cuatro casos que se presentaron con síndrome hipotalámico al momento de desarrollar una recaída de LLA en el SNC.

Caracterización del perfil de reordenamientos génicos de inmunoglobulinas y receptores de linfocitos T en leucemia linfoblástica aguda pediátrica / Pattern of immunoglobulins and T lymphocyte receptor gene rearrangements in childhood acute lymphoblastic leukemia / Caracterização do perfil de rearranjos gênicos de imunoglobulinas e receptores de linfócitos T na leucemia linfoide aguda pediátrica

Resumen Durante la ontogenia linfocitaria se produce el reordenamiento de los segmentos génicos V-(D)-J que codifican para la región variable de las cadenas de inmunoglobulinas (Ig) y receptores de linfocitos T (TCR). Durante este proceso, los segmentos se reordenan al azar y ocurren deleciones e inserciones de nucleótidos en la región de unión entre ellos. Los objetivos del presente trabajo fueron describir las incidencias de los reordenamientos Ig/TCR y de los segmentos V-(D)-J involucrados, en niños con leucemia linfoblástica aguda (LLA). Para ello se estudiaron 769 pacientes pediátricos con LLA, diagnosticados entre 1999 y 2018 por los centros de la Sociedad Argentina de Hemato-Oncología Pediátrica. Se caracterizaron reordenamientos de Ig/TCR mediante PCR-multiplex y secuenciación para la búsqueda de recombinaciones génicas IGH, IGK, TCRB, TCRG y TCRD, en muestras de ADN obtenidas de médula ósea o sangre periférica al diagnóstico. El 95% (n=730) de los casos presentaron reordenamientos Ig/TCR. En el 68% de los casos se caracterizaron recombinaciones génicas IGH, en 43% IGK, en 25% TCRB, en 49% TCRG y en el 55% TCRD. Se caracterizó un total de 2506 reordenamientos de Ig/TCR que correspondían 1161 a inmunoglobulinas y 1345 a TCR. En la mayoría de los casos los reordenamientos de IGH fueron completos, IGK involucró a IGKde, TRCB se reordenó frecuentemente con el segmento Jb2, TCRG involucró preferentemente a Vg9 y los TCRD fueron principalmente reordenamientos incompletos. Este trabajo constituye el primer estudio realizado en la Argentina sobre la caracterización de reordenamientos Ig/TCR en un número muy significativo de pacientes con LLA pediátrica.

Abstract During lymphocyte ontogeny, the variable region of immunoglobulin (Ig) and T-cell receptor (TCR) is generated by rearrangements of the V-(D)-J gene segments. In this random process, nucleotide deletions and insertions occur between V-(D)-J segments. The aims of this work were to describe the incidence of Ig/TCR rearrangements, and the V-(D)-J segments involved in acute lymphoblastic leukemia (ALL) patients. With this purpose, 769 pediatric ALL patients belonging to Sociedad Argentina de Hemato-Oncología Pediátrica, diagnosed between 1999 and 2018, were studied. Ig/TCR rearrangements were characterized by multiplex PCR and sequencing to evaluate IGH, IGK, TCRB, TCRG and TCRD rearrangements in DNA samples obtained at diagnosis from bone marrow or peripheral blood. In total, 95% (n=730) of patients disclosed Ig/TCR rearrangements. IGH rearrangements were detected in 68% of cases; in 43% IGK, in 25% TCRB, in 49% TCRG and in 55% of cases, TCRD. A total of 2506 Ig/TCR rearrangements were characterized, being 1161 immunoglobulins and 1345 TCR. In most cases, IGH rearrangements were complete, IGK involved IGKde, TRCB was frequently rearranged with the Jb2 segment, TCRG preferentially involved Vg9, and TCRDs were mostly incomplete rearrangements. This work is the first study of Ig/TCR rearrangements characterization in a very significant number of childhood ALL carried out in Argentina.

Resumo Durante a ontogenia dos linfócitos, ocorre um rearranjo dos segmentos gênicos V-(D)-J que codificam para a região variável das cadeias de imunoglobulinas (Ig) e receptores de linfócitos T (TCR). Durante esse processo, os segmentos reorganizam-se aleatoriamente e exclusões e inserções de nucleotídeos ocorrem na região da união entre eles. Os objetivos do presente trabalho foram descrever as incidências dos rearranjos Ig/TCR e dos segmentos V-(D)-J envolvidos, em crianças com leucemia linfoide aguda (LLA). Para tanto, foram estudados 769 pacientes pediátricos com LLA, diagnosticados entre 1999 e 2018 pelos centros da Sociedade Argentina de Hemato-Oncologia Pediátrica. Rearranjos de Ig/TCR foram caracterizados através de PCR-multiplex e sequenciação para procurar recombinações gênicas IGH, IGK, TCRB, TCRG e TCRD em amostras de DNA obtidas da medula óssea ou sangue periférico no diagnóstico. Do total de pacientes estudados, 95% (n=730) apresentaram rearranjos de Ig/TCR. Os rearranjos gênicos IGH foram caracterizados em 68% dos casos, em 43% de IGK, em 25% de TCRB, em 49% de TCRG e em 55% de TCRD. Foi caracterizado um total de 2506 rearranjos de Ig/TCR, correspondendo 1161 a imunoglobulinas e 1345 a TCR. Na maioria dos casos, os rearranjos de IGH foram concluídos, o IGK envolveu o IGKde, o TRCB foi frequentemente rearranjado com o segmento Jb2, o TCRG preferencialmente envolveu o Vg9 e os TCRDs foram principalmente os rearranjos incompletos. Este trabalho constitui o primeiro estudo realizado na Argentina sobre a caracterização de rearranjos de Ig/TCR em um número muito significativo de pacientes com LLA pediátrica.

No benefit of Interfant protocols compared to BFM-based protocols for infants with acute lymphoblastic leukemia. Results from an institution in Argentina.

BACKGROUND: Infant acute lymphoblastic leukemia (ALL) is an infrequent disease characterized by clinical and biological features related to poor prognosis. Adapted therapies were designed without a clear consensus regarding the best treatment options. We aimed to compare the outcome between infant ALL cases receiving Interfant versus BFM-based protocols. PROCEDURE: This is a retrospective observational study. From April 1990 to June 2018, infant ALL cases were enrolled in one of the five consecutive treatment protocols. Clinical, demographic, and biological features and outcome were evaluated. A comparative analysis was performed between Interfant protocols and BFM-based protocols. RESULTS: During the studied period, 1913 ALL patients were admitted and 116 (6%) were infants. Treatment administered was: ALL-BFM'90 (n = 16), 1-ALL96-BFM/HPG (n = 7), Interfant-99 (n = 39), Interfant-06 (n = 35), and ALLIC-BFM'2009 (n = 19). The 5-year event-free survival probability (EFSp) was 31.9(standard error [SE] 4.6)% for the entire population, with a significant difference among risk groups according to Interfant-06 criteria (P = .0029). KMT2A-rearrangement status was the strongest prognostic factor (P = .048), independently of the protocol strategy. The median time for relapse was 24.1 months for patients with minimal residual disease (MRD)-negative versus 11.5 months for those with MRD-positive (P = .0386). EFSp and cumulative relapse risk probability (CRRp) were similar. Interfant protocols showed comparable induction (8.1% vs 7.1%, P = .852) and complete remission mortality (21.6% vs 28.6%, P = .438), failing to reduce the relapse rate (48.5% vs 30.7%, P = .149). CONCLUSIONS: Interfant protocols and BFM-based protocols presented comparable results. The risk group stratification proposed by Interfant-06 was validated by our results, and MRD seems useful to identify patients with an increased risk of early relapse.

[Epidemiology and risk factors for prolonged hospital length of stay in children with leukemia and bacteremia. Cohort study]. / Epidemiología y factores de riesgo de internación prolongada en niños con leucemia y bacteriemia. Estudio de cohorte.

INTRODUCTION: Bacteremia is a frequent complication in children with cancer, which is associated with greater severity, prolonged hospitalization and mortality. Prolonged hospitalization conditions greater morbidity and risk of acquisition of intranosocomial infections. AIM: To describe risk factors for prolonged hospital length of stay in children with leukemia and bacteremia. METHODS: Cohort study. Episodes of bacteremia in patients with leukemia at Garrahan Hospital from 1/1/2015 to 31/12/2016 were reviewed. We compared data from patients with a LOS of 14 days or more with those admitted for less than 14 days. Bivariate and logistic regression analysis was performed. We used Stata 13 statistical package. RESULTS: n = 121. Median age 59 months.81 patients (67%) had a diagnosis of acute lymphoblastic leukemia, followed by acute myeloid leukemia in 40 (33%). 96 patients (79%) had a central venous catheter (CVC), 94 patients (78%) were neutropenic. Blood cultures were positive for Enterobacteriaceae in 55 cases (45%), coagulase-negative staphylococci in 28 cases (23%), Group viridans Streptococcus in 19 (16%), Pseudomonas aeruginosa in 8 (7%). (9%). By the multivariate analysis, three factors remained significantly associated with length of stay of more than 14 days: CVC associated bacteremia (OR 21,73; CI95% 1.2-43.2; p 0.04), severe neutropenia (OR 1.75; CI95% 1.82-1.28; p 0.03) and coinfection (OR 27.4; CI95% 2.8-260.8; p 0.004). CONCLUSION: CVC associated bacteremia, severe neutropenia and viral coinfection were associated with hospital LOS of more than 14 days.

Leucemia linfoblástica aguda en niños con síndrome de Down: análisis comparativo con pacientes sin síndrome de Down / Acute lymphoblastic leukemia in children with Down syndrome: Comparative analysis versus patients without Down syndrome

Introducción: Los niños con síndrome de Down (SD) tienen mayor frecuencia de leucemia linfoblástica aguda (LLA) y menor supervivencia que pacientes sin síndrome de Down (NSD). Analizamos las características clínicas, demográficas-biológicas y respuestas al tratamiento en SD-LLA versus NSD-LLA. Pacientes y métodos: Pacientes (0-19 años) con LLA desde enero de 1990 a noviembre de 2016. Se compararon características demográficas biológicas y respuestas al tratamiento con chi cuadrado y Wilcoxon rank sum. La supervivencia global y el intervalo libre de eventos (ILE) se analizaron con Kaplan-Meier y el test log-rank. Resultados: Se incluyeron 1795 pacientes, 54 con SD. Los SD-LLA presentaron edad mayor (p= 0,0189). T odos inmuno fenotipo precursor-B, con menor incidencia de anomalías recurrentes (p < 0,0001). Demostraron mejor tasa de respuesta a prednisona (p= 0,09) y mayor mortalidad en inducción y remisión completa (p < 0,0001). Todas las muertes de los SD-LLA fueron relacionadas con el tratamiento. La sobrevida libre de eventos en niños SD-LLA vs.NSD-LLA fue 47 (± 8)% vs. 73 (± 1)% (p= 0,006) y el ILE de los SD-LLA vs. NSD-LLA fue 54 (± 9)% vs. 75 (± 1)% (p= 0,0297). La tasa de recaídas fue similar en ambos grupos (p= 0,6894). El ILE de los SD-LLA fue menor en el grupo de 6-9 años: 39 (± 19)% (p= 0,7885). Conclusiones: Los niños de 6-9 años con SD-LLA años presentó menor sobrevida. Aunque estos niños presentaron una mejor respuesta temprana, la sobrevida libre de eventos e ILE fueron menores debido a la mortalidad relacionada con el tratamiento.

Introduction. Children with Down syndrome (DS) more commonly have acute lymphoblastic leukemia (ALL) and a lower survival rate than those without Down syndrome (WDS). We analyzed the clinical, demographic, and biological characteristics and treatment response of children with DS-ALL versus those WDS-ALL. Patients and methods: Patients with ALL between January 1990 and November 2016. The demographic and biologic characteristics and treatment response were compared using the χ² and Wilcoxon rank-sum tests. The overall survival and event-free interval (EFI) were analyzed using the Kaplan-Meier and log-rank tests. Results. 1795 patients were included; 54 had DS. Patients with DS-ALL were older (p= 0.0189). All had B-cell precursor immunophenotype and a lower incidence of recurrent abnormalities (p < 0.0001). They showed a better response rate to prednisone (p= 0.09) and a higher mortality in induction and complete remission (p < 0.0001). All deaths of patients with DS-ALL were treatment-related. The event-free survival (EFS) was 47% (± 8%) versus 73% (± 1%) (p= 0.006) and the EFI was 54% (± 9%) versus 75% (± 1%) (p= 0.0297) among patients with DS-ALL versus those WDS-ALL, respectively. The rate of relapse was similar in both groups (p= 0.6894). The EFI of patients with DS-ALL was lower in the group aged 6-9 years: 39% (± 19%) (p= 0.7885). Conclusions. A lower survival was observed among children aged 6-9 years with DS-ALL. Although these children showed a better early response, their EFS and EFI were lower due to treatment-related mortality.

Acute lymphoblastic leukemia in children with Down syndrome: Comparative analysis versus patients without Down syndrome. / Leucemia linfoblástica aguda en niños con síndrome de Down: análisis comparativo con pacientes sin síndrome de Down.

INTRODUCTION: Children with Down syndrome (DS) more commonly have acute lymphoblastic leukemia (ALL) and a lower survival rate than those without Down syndrome (WDS). We analyzed the clinical, demographic, and biological characteristics and treatment response of children with DS-ALL versus those WDS-ALL. Patients and methods: Patients with ALL between January 1990 and November 2016. The demographic and biologic characteristics and treatment response were compared using the χ² and Wilcoxon rank-sum tests. The overall survival and event-free interval (EFI) were analyzed using the Kaplan-Meier and log-rank tests. RESULTS: 1795 patients were included; 54 had DS. Patients with DS-ALL were older (p= 0.0189). All had B-cell precursor immunophenotype and a lower incidence of recurrent abnormalities (p < 0.0001). They showed a better response rate to prednisone (p= 0.09) and a higher mortality in induction and complete remission (p < 0.0001). All deaths of patients with DS-ALL were treatment-related. The event-free survival (EFS) was 47% (± 8%) versus 73% (± 1%) (p= 0.006) and the EFI was 54% (± 9%) versus 75% (± 1%) (p= 0.0297) among patients with DS-ALL versus those WDS-ALL, respectively. The rate of relapse was similar in both groups (p= 0.6894). The EFI of patients with DS-ALL was lower in the group aged 6-9 years: 39% (± 19%) (p= 0.7885). CONCLUSIONS: A lower survival was observed among children aged 6-9 years with DS-ALL. Although these children showed a better early response, their EFS and EFI were lower due to treatment-related mortality.

Introducción: Los niños con síndrome de Down (SD) tienen mayor frecuencia de leucemia linfoblástica aguda (LLA) y menor supervivencia que pacientes sin síndrome de Down (NSD). Analizamos las características clínicas, demográficas-biológicas y respuestas al tratamiento en SD-LLA versus NSD-LLA. Pacientes y métodos: Pacientes (0-19 años) con LLA desde enero de 1990 a noviembre de 2016. Se compararon características demográficas biológicas y respuestas al tratamiento con chi cuadrado y Wilcoxon rank sum. La supervivencia global y el intervalo libre de eventos (ILE) se analizaron con Kaplan-Meier y el test log-rank. Resultados: Se incluyeron 1795 pacientes, 54 con SD. Los SD-LLA presentaron edad mayor (p= 0,0189). Todos inmuno fenotipo precursor-B, con menor incidencia de anomalías recurrentes (p < 0,0001). Demostraron mejor tasa de respuesta a prednisona (p= 0,09) y mayor mortalidad en inducción y remisión completa (p < 0,0001). Todas las muertes de los SD-LLA fueron relacionadas con el tratamiento. La sobrevida libre de eventos en niños SD-LLA vs.NSD-LLA fue 47 (± 8)% vs. 73 (± 1)% (p= 0,006) y el ILE de los SD-LLA vs. NSD-LLA fue 54 (± 9)% vs. 75 (± 1)% (p= 0,0297). La tasa de recaídas fue similar en ambos grupos (p= 0,6894). El ILE de los SD-LLA fue menor en el grupo de 6-9 años: 39 (± 19)% (p= 0,7885). Conclusiones: Los niños de 6-9 años con SD-LLA años presentó menor sobrevida. Aunque estos niños presentaron una mejor respuesta temprana, la sobrevida libre de eventos e ILE fueron menores debido a la mortalidad relacionada con el tratamiento.

Cytoplasmic CD3 expression in infant acute megakaryoblastic leukemia: A new ambiguous lineage subtype?

Several conventions have been established in order to define and characterize Mixed Phenotype Acute Leukemia (MPAL). However, megakaryocytic markers have not been included in the definition of MPAL neither in the European Group for the Immunological Characterization of Leukemias (EGIL) proposal nor in any of the WHO Classification of Tumors issues. We report four pediatric acute leukemia (AL) cases (prevalence: 0.18%) with megakaryoblasts co-expressing the T-specific antigen CD3 (cytoplasmic), together with a very homogeneous antigen profile of immature cells and other lymphoid traits. In one case, the presence of epsilon CD3 mRNA was confirmed as well on sorted CD34+ blasts. All four cases were infants, and two of them disclosed trisomy 21 in the blast population (not constitutional) without being children with Down Syndrome. They were homogeneously treated with AML schemes, achieving all four CR. However, 3 patients relapsed early. Only one patient is alive and remain disease-free, with a long follow-up. Even though cyCD3 was the only T cell marker expressed, its specificity entails the consideration of these cases as a new subtype of MPAL Megakaryoblastic/T, keeping this in mind when designing diagnostic panels. Detection and report of these cases are necessary so as to further characterize them in order to define the most appropriate treatment.

Acute and sub-acute neurological toxicity in children treated for acute lymphoblastic leukemia.

Eighty percent of children with acute lymphoblastic leukemia (ALL) survive with current treatments. Neurotoxicity is an infrequent adverse event. We describe clinical presentations of neurological toxicity, phases of treatment when these adverse events were more frequent and patients ́ outcome. From January-1995 to December-2015, 1379 ALL cases were admitted. Neurotoxicity was diagnosed in 49 patients (3.6%) and classified according to neurological syndromes. Medical records, laboratory-tests and images were reviewed. The diagnosed syndromes were: a) Methotrexate-leukoencephalopathy (MLE) (35.4%); b) Cerebral-venous-sinus thrombosis following L-Asparaginase administration (26.5%); c) Vincristine-induced-vocal-cord paralysis (VVCP) (14.2%); d) Stroke-associated vasospasm (14%), after high-dose methotrexate e) Severe polyneuropathy (6.1%); f) Methotrexate myelopathy (2%); and g) Pseudotumor-cerebri (2%) associated with corticosteroid therapy. Neurotoxicity was diagnosed during induction in 55% of cases. We conclude that MLE was the most frequent syndrome. VVCP was observed in infants and Down patients. Seizure was the most common symptom and toxicity occurred mainly during induction phase.

Epidemiología y factores de riesgo de internación prolongada en niños con leucemia y bacteriemia: estudio de cohorte / Epidemiology and risk factors for prolonged hospital length of stay in children with leukemia and bacteremia: cohort study

Resumen Introducción: La bacteriemia constituye una complicacion frecuente en los niños con cáncer, que se asocia a mayor gravedad, internación prolongada y mortalidad. La internación prolongada condiciona mayor morbilidad y riesgo de adquisición de infecciones intranosocomiales. Objetivo: Analizar factores de riesgo de internación prolongada en niños con leucemia y bacteriemia. Pacientes y Métodos: Cohorte retrospectiva. Se incluyeron niños con leucemia internados en el Hospital Garrahan entre 1/1/2015 y 31/12/2016 con bacteriemia. Se compararon características de pacientes con internaciones menores o mayores a 14 días. Se realizó un análisis bivariado y modelo de regresión logística. Se utilizó Stata 13. Resultados: n = 121. Mediana de edad 59 meses. Tenían leucemia linfoblastica 81 pacientes (67%) y leucemia mieloblástica 40 (33%). Tenían catéter venoso central (CVC) 96 de los niños (79%), neutropenia 94 (78%), neutropenia menor a 100 neutrófilos 79 (65%). La identificación en hemocultivos fue: 55 casos (45%) enterobacterias, 28 (23%) Staphylococcus coagulasa negativa, Streptococcus spp grupo viridans 19 (16%), Pseudomonas aeruginosa 8 (7%). Huo co-infección viral en 14 pacientes (12%).Tuvieron menos de 14 días de internación 71 pacientes (59%) y mayor período 50 (41%). En el análisis multivariado la bacteriemia asociada a CVC (OR 21,73; IC95% 1,2-43,20; p 0,04), neutropenia profunda al ingreso (OR 1,75; IC95% 1,82-1,28; p 0,03) y co-infección viral (OR 27,42; IC95% 2,88-260,83; p 0,004) fueron factores de riesgo de internación > 14 días. Conclusiones: La bacteriemia asociada a CVC, la neutropenia profunda al ingreso y la co-infección se asociaron con una internación igual o mayor a 14 días.

ABSTRACT Introduction: Bacteremia is a frequent complication in children with cancer, which is associated with greater severity, prolonged hospitalization and mortality. Prolonged hospitalization conditions greater morbidity and risk of acquisition of intranosocomial infections. Aim: To describe risk factors for prolonged hospital length of stay in children with leukemia and bacteremia. Methods: Cohort study. Episodes of bacteremia in patients with leukemia at Garrahan Hospital from 1/1/2015 to 31/12/2016 were reviewed. We compared data from patients with a LOS of 14 days or more with those admitted for less than 14 days. Bivariate and logistic regression analysis was performed. We used Stata 13 statistical package. Results: n = 121. Median age 59 months.81 patients (67%) had a diagnosis of acute lymphoblastic leukemia, followed by acute myeloid leukemia in 40 (33%). 96 patients (79%) had a central venous catheter (CVC), 94 patients (78%) were neutropenic. Blood cultures were positive for Enterobacteriaceae in 55 cases (45%), coagulase-negative staphylococci in 28 cases (23%), Group viridans Streptococcus in 19 (16%), Pseudomonas aeruginosa in 8 (7%). (9%). By the multivariate analysis, three factors remained significantly associated with length of stay of more than 14 days: CVC associated bacteremia (OR 21,73; CI95% 1.2-43.2; p 0.04), severe neutropenia (OR 1.75; CI95% 1.82-1.28; p 0.03) and coinfection (OR 27.4; CI95% 2.8-260.8; p 0.004). Conclusion: CVC associated bacteremia, severe neutropenia and viral coinfection were associated with hospital LOS of more than 14 days.

Children and Adolescent Hodgkin Lymphoma in Argentina: Long-term Results After Combined ABVD and Restricted Radiotherapy.

OBJECTIVE: Prospective analysis of clinical characteristics and long-term treatment results of a pediatric cohort with Hodgkin lymphoma (HL) treated in a single institution with ABVD and restricted radiotherapy (RT). PATIENTS AND METHODS: Between September 2000 and December 2015, 165 new consecutive assessable patients with HL were registered at our institution. Lymphocyte predominant nodular HL was excluded. Low risk (LR) patients were stage I and IIA (no bulky disease, <4 involved ganglionar areas and no lung hilar nodes), high risk (HR) was assigned to stage IV and any other stage with bulky mediastinum. The rest of the cohort was treated as intermediate risk (IR). Chemotherapy for LR and IR patients was 4 and 6 courses of ABVD regimen, respectively. These subsets received Low-dose involved field radiotherapy only in case of partial remission at the end of chemotherapy (21 Gy in initially involved areas, plus 14 Gy boost on residual disease). The HR group was treated with 6 courses of ABVD followed always with 21 Gy involved field radiotherapy if complete remission (CR) was achieved. A boost of 14 Gy was added to residual disease in case of partial remission. RESULTS: Median age was 10.6 years (range, 2.7 to 17 y). Males: 117 (71%); females: 48 (29%). Eighteen (11%) patients were stage I, 76 (46%) stage II, 35 (21%) stage III, and 35 (21%) stage IV. Forty-nine (30%) patients were assigned to LR, 49 (30%) to IR, and 67 (40%) to HR. Forty-three patients (26%) had "bulky" mediastinum involvement. One hundred thirty (79%) patients achieved CR after chemotherapy and 161 (98%) after RT. Four patients (all HR), did not respond to initial therapy and died of disease. One patient died in first CR due to adenovirus infection on previously therapy-related damaged lungs. Seventeen (10%) patients relapsed and 13 of them remained in second CR after further therapy. Seventy-six (46%) patients could be spared from RT and cured of disease (88% of LR patients and 67% of IR patients). With a median follow-up of 5 years, event free and overall survival were 0.84 (SE: 0.03) and 0.95 (SE: 0.02), respectively. Overall survival according to risk group was 1 for LR, 0.93 for IR, and 0.85 for HR. Acute toxicity and late effects due to therapy were not significant. CONCLUSIONS: The strategy of avoiding RT for LR and IR patients that responded completely to ABVD chemotherapy achieved very good results. For the HR group, the combination of 6 cycles of ABVD and Low-dose involved field radiotherapy was efficacious with similar good results. Nearly half of the patients could be cured without RT.

Second Neoplasms in Children Following a Treatment for Acute Leukemia and/or Lymphoma: 29 Years of Experience in a Single Institution in Argentina.

INTRODUCTION: Childhood acute leukemias (AL) and lymphomas achieve good survival rates. However, second neoplasms (SN) are a devastating event. METHODS: From August 1987 to December 2016, 34 of 3321 (1%) patients with diagnosis of AL or lymphoma developed SN. SN were AL (n=16), CNS tumors (n=5), endocrinal tumors (n=3), lymphomas (n=2), schwannoma (n=2) assorted sarcomas (n=4), retinal melanoma (n=1), and Vanek tumor (n=1). Median latency was 51 (range, 10 to 110) months for hematological malignancies and 119 (range, 25 to 236) months for solid tumors (P=0.001). RESULTS: A total of 33 patients with SN were treated taking into account cumulative doses of anthracyclines and radiotherapy. Twenty-three (67.6%) patients achieved complete remission (CR), 5 died early during therapy and 5 were refractory or partial responders. Six patients presented relapses of the SN and 1 died in CR. Seventeen patients remain alive in CR, with a median follow-up of 110 (range, 4 to 276) months. CONCLUSIONS: (1) The latency period was significantly longer for patients developing solid tumors than for those developing AL. (2) AL was the most frequent SN. (3) Our results strongly encourage giving standard therapy to SN, considering cumulative doses of previous treatment, since similar probabilities of surviving as "de novo" counterparts can be achieved.

Series de Pediatría Garrahan. El niño con cáncer / Garrahan Pediatrics Series. The child with cancer

La sobrevida de los niños con enfermedades oncológicas ha aumentado de manera considerable en las últimas décadas y este logro se alcanzó, entre otros factores, gracias a la detección temprana de la patología, los avances en los métodos diagnósticos, la administración de terapéuticas específicas adaptadas al riesgo y la adecuada implementación de medidas de soporte. Sin embargo, el cuidado de estos pacientes sigue representando un difícil desafío y requiere la conformación de equipos en los que el pediatra cumple un rol fundamental en la atención conjunta con el oncólogo y en la coordinación de la intervención de los demás especialistas. Este nuevo volumen aborda esta interesante temática y entre sus características destacadas se encuentran: El estudio de importantes temas, como la prevención del cáncer en pediatría en el mundo y en la Argentina, y la necesidad de construir programas de integración, educación e investigación en el cáncer pediátrico; el niño con una masa abdominal, con sus estrategias diagnósticas y las eventuales urgencias metabólicas, infectológicas y nutricionales durante el período de inducción, y cómo anticiparlas y prevenirlas; las situaciones clínicas de riesgo, como la compresión medular, el síndrome de vena cava superior y las complicaciones asociadas con la utilización de irinotecán; los aspectos ginecológicos en las niñas con cáncer, como las conductas frente al riesgo de sangrado menstrual durante el período de inducción, la actividad sexual y el embarazo durante el tratamiento, y la preservación de la fertilidad; y la leucemia linfoblástica aguda en etapa de reinducción, período especialmente significativo por la elevada morbilidad y las dificultades en el soporte clínico que requieren estos pacientes. La inclusión en todos los capítulos de casos clínicos ejemplificadores con su evolución y desenlace, textos destacados con los conceptos más importantes y puntos clave para recordar. Una obra sólida y práctica, que transmite la experiencia de los profesionales de una institución del prestigio internacional del Hospital de Pediatría Prof. Dr. Juan P. Garrahan, dedicada a todos los pediatras dondequiera que trabajen al servicio de los niños.

Inmunidad humoral a tétanos, sarampión y rubéola en niños con leucemia linfoblástica aguda luego del tratamiento quimioterápico / Humoral immunity to tetanus, measles and rubella in children with acute lymphoblastic leukemia after chemotherapy

Los regímenes de quimioterapia y los avances en el soporte clínico han mejorado la supervivencia de los niños con leucemia linfoblástica aguda. Son temas de preocupación las secuelas del tratamiento, entre ellas, el daño inmunológico inducido por la terapia inmunosupresora, que se refleja en la pérdida de niveles protectores de anticuerpos provistos por inmunizaciones previas. Nuestro objetivo fue evaluar la presencia de títulos protectores de anticuerpos para sarampión, rubéola y tétanos en pacientes con leucemia linfoblástica aguda luego de haber finalizado el tratamiento quimioterápico. Se incluyeron 61 niños con leucemia linfoblástica aguda asistidos en el Hospital Garrahan, que habían finalizado el tratamiento, como mínimo, 6 meses antes y con vacunación completa previa al diagnóstico. Las tasas de anticuerpos protectores fueron sarampión: 46% (IC 32-59); tétanos: 53% (IC 40-67); rubéola: 60% (IC 47-63). Estos resultados refuerzan la necesidad de reconsiderar la revacunación en este grupo de pacientes.

Chemotherapy regimens and clinical support advances have improved survival in children with acute lymphoblastic leukemia. The after-effects of treatment are a reason for concern, including damage to the immune system induced by immunosuppressive therapy which is reflected in the loss of antibody protection provided by prior immunizations. Our goal was to assess the presence of measles, rubella, and tetanus protective antibody titers among patients with acute lymphoblastic leukemia after completing chemotherapy. Sixty-one children with acute lymphoblastic leukemia seen at the Hospital Garrahan were included; patients had finished their chemotherapy at least 6 months earlier and had a complete immunization schedule before diagnosis. The rates of protective antibodies were 46% (CI: 32-59) for measles, 53% (CI 40-67) for tetanus, and 60% (CI 47-63) for rubella. These results strengthen the need to reconsider revaccination in this group of patients.

Humoral immunity to tetanus, measles and rubella in children with acute lymphoblastic leukemia after chemotherapy. / Inmunidad humoral a tétanos, sarampión y rubéola en niños con leucemia linfoblástica aguda luego del tratamiento quimioterápico.

Chemotherapy regimens and clinical support advances have improved survival in children with acute lymphoblastic leukemia. The after-effects of treatment are a reason for concern, including damage to the immune system induced by immunosuppressive therapy which is reflected in the loss of antibody protection provided by prior immunizations. Our goal was to assess the presence of measles, rubella, and tetanus protective antibody titers among patients with acute lymphoblastic leukemia after completing chemotherapy. Sixty-one children with acute lymphoblastic leukemia seen at the Hospital Garrahan were included; patients had finished their chemotherapy at least 6 months earlier and had a complete immunization schedule before diagnosis. The rates of protective antibodies were 46% (CI: 32-59) for measles, 53% (CI 40-67) for tetanus, and 60% (CI 47-63) for rubella. These results strengthen the need to reconsider revaccination in this group of patients.

Los regímenes de quimioterapia y los avances en el soporte clínico han mejorado la supervivencia de los niños con leucemia linfoblástica aguda. Son temas de preocupación las secuelas del tratamiento, entre ellas, el daño inmunológico inducido por la terapia inmunosupresora, que se refleja en la pérdida de niveles protectores de anticuerpos provistos por inmunizaciones previas. Nuestro objetivo fue evaluar la presencia de títulos protectores de anticuerpos para sarampión, rubéola y tétanos en pacientes con leucemia linfoblástica aguda luego de haber finalizado el tratamiento quimioterápico. Se incluyeron 61 niños con leucemia linfoblástica aguda asistidos en el Hospital Garrahan, que habían finalizado el tratamiento, como mínimo, 6 meses antes y con vacunación completa previa al diagnóstico. Las tasas de anticuerpos protectores fueron sarampión: 46% (IC 32-59); tétanos: 53% (IC 40-67); rubéola: 60% (IC 47-63). Estos resultados refuerzan la necesidad de reconsiderar la revacunación en este grupo de pacientes.