Enfermedad mínima residual en leucemia mieloide aguda no promielocítica: Resultados preliminares de un estudio colaborativo internacional / Minimal residual disease in non-myelocytic acute myeloid leukemia: preliminary results of an international collaborative study

A pesar de los avances en los protocolos de tratamiento y en las medidas de soporte en pacientes con Leucemia Mieloide Aguda (LMA), 27% presentan recaídas de la enfermedad. Esto se debe, entre otras causas, a la persistencia de pequeñas cantidades de células malignas (blastos) resistentes a la terapia. Estas pequeñas cantidades de blastos remanentes se denominan Enfermedad Mínima Residual (EMR). La determinación de EMR requiere de técnicas no solo muy sensibles, sino también específicas, y permite evaluar la respuesta individual a la terapia. La introducción de la EMR como parámetro de respuesta y estratificación está bien definida en Leucemia Linfoblástica Aguda (LLA). Por el contrario, aunque existen publicaciones sobre el impacto pronóstico de la EMR en LMA, aún no se encuentra incluida en forma sistemática en los protocolos nacionales actuales, entre otros motivos, por lo laborioso de la determinación y por la necesidad de validación de la misma. Debe tenerse en cuenta que el inmunofenotipo de los blastos mieloides suele ser más heterogéneo que el de los blastos en LLA, presentando, en muchos casos, subpoblaciones diferentes entre sí, lo cual dificulta su detección certera y no hay consenso definido en cuanto a la metodología más eficaz. En este trabajo describimos una nueva estrategia de marcación y análisis estandarizada en un estudio multicéntrico internacional para LMA y la utilidad de la EMR como parámetro de respuesta y de estratificación. Asimismo, detallamos los resultados preliminares de nuestra cohorte de pacientes (AU)

Despite the improvement in treatment and supportive care of patients with Acute Myeloid Leukemia (AML), 27% of them relapse. This is due to the persistence of small amounts of malignant cells (blasts) resistant to therapy, among other causes. These small amounts of blasts are called Minimal Residual Disease (MRD). The determination of MRD requires not only techniques with high sensitivity but also with high specificity, and allows to evaluate the individual response to treatment. The introduction of MRD as a response parameter is well established in Acute Lymphoblastic Leukemia (ALL), and it is used in current stratification protocols. On the other hand, even though there are some reports regarding the prognostic impact of MRD in AML, it is still not included in the current national protocols due to the lack of validation of the determination, among other causes. This is due to the fact that the immunophenotype of myeloid blasts is more heterogeneous than in ALL, presenting different subpopulations, which difficults their accurate detection. Thus, there is still no consensus regarding the most effective approach. In this article, we describe a new staining and analysis strategy standardized by an international multicentric study, and the utility of EMR as a response and stratification parameter. Additionally, we show the preliminary results of our patient cohort. (AU)

Epidemiología y patrones de sensibilidad a los antimicrobianos de microorganismos aislados de hemocultivos en niños con leucemia aguda / Epidemiology and sensitivity patterns of antimicrobials in microorganisms isolated in blood cultures of children with acute leukemia

Las infecciones bacterianas son una de las principales causas de morbimortalidad en los niños con cáncer. Nuestro objetivo fue describir y comparar las características clínicas y los microorganismos causantes de bacteriemias con su sensibilidad antimicrobiana en niños con diagnóstico de LLA y LMA. Se realizó un estudio observacional, descriptivo entre julio-2016 y junio-2018. Se incluyeron todos los episodios de bacteriemia (EpB) en pacientes de 0 a 18 años con diagnóstico de LLA y LMA. Se documentaron datos epidemiológicos y demográficos de los pacientes y datos microbiológicos de los aislamientos de hemocultivos positivos. Se utilizó stata13. Se incluyeron 258 EpB en 167 pacientes; el 55% eran varones. La mediana de edad fue 81 meses (RIC 39-130). En 215 EpB (83%) se registró la presencia de algún tipo de catéter; neutropenia en 193 EpB (75%), neutropenia severa en 98/258 EpB (38%). Se pudo determinar el foco clínico en 152 EpB (59%). Ciento diez pacientes tenían LLA y 57 LMA. En LLA predominaron las enterobacterias, en LMA los cocos gram positivos. Se observó asociación entre LMA y estreptococos del grupo Viridans (p<0,01) y entre LLA y P.aeruginosa (p 0,01). Con respecto a la sensibilidad hubo 11% y 17% de bacilos negativos multirresistentes en LLA y LMA respectivamente. Todos los estafilococos coagulasa negativos fueron meticilino resistentes. La mayoría de los pacientes tenía algún tipo de catéter y neutropenia. Se observó un predominio de enterobacterias con bajos niveles de resistencia antibiótica. Estos resultados son importantes para conocer la epidemiología local y establecer tratamientos empíricos adecuados (AU)

Bacterial infections are one of the main causes of morbidity and mortality in children with cancer. Our aim was to describe and compare the clinical features and bacteremia-causing microorganisms together with their antimicrobial sensitivity in acute lymphocytic (ALL) and acute myelocytic leukemia (AML). A descriptive observational study was conducted between July 2016 and June 2018. All episodes of bacteremia (EpB) in patients between 0 and 18 years of age with ALL and AML were included. All epidemiological and demographic data of the patients and microbiological information of the isolates of the positive blood cultures were recorded. For statistical analysis stata13 was used. Overall 258 EpB in 167 patients were included; 55% were boys. Median age was 81 months (IQR 39-130). In 215 EpB (83%) some type of catheter was involved; neutropenia was observed in 193 EpB (75%) and severe neutropenia in 98/258 EpB (38%). A clinical focus could be determined in 152 EpB (59%). Of all patients, 110 had ALL and 57 AML. The predominant micro-organisms were enterobacteria in ALL and gram-positive cocci in AML. An association was observed between AML and the viridans group of streptococci (p<0.01) and between ALL and P. aeruginosa (p 0.01). Regarding sensitivity, there were 11% and 17% of multiresistant negative bacilli in ALL and AML, respectively. All coagulase-negative staphylococci weer methicillin resistant. The majority of patients had some type of catheter and neutropenia. Predominance of enterobacteria with low levels of resistance to antibiotics was observed. These results are important to understand the local epidemiology and establish adequate empirical therapies (AU)

NPM1, FLT3 and CEBPA mutations in pediatric patients with AML from Argentina: incidence and prognostic value.

Mutations in NPM1, FLT3 and CEBPA genes are found in 25-35 % of adult acute myeloblastic leukemia (AML) cases and correlate with prognosis. To date, there have been no reports about these mutations in pediatric AML from Argentina. The aims of the present study were to describe the incidence of NPM1, FLT3 and CEBPA mutations and to analyze their prognostic impact in this population. The incidences of these mutations within a population of 216 pediatric AML cases were: NPM1-mutated 4.2 %, CEBPA-mutated 1.9 %, FLT3-ITD 10.2 % and FLT3-TKD 7.9 %. Among 33 patients with normal karyotype, we found significantly higher frequencies for NPM1-mutated 24.2 % and CEBPA-mutated 12.1 %. Overall survival (pOS) for the 163 eligible non-acute promyelocytic leukemia cases was 46.2 ± 4.3 %, while leukemia-free survival probability was 51.0 ± 4.4 % (n = 135). The NPM1-mutated/FLT3-ITD-negative genotype showed better outcome than any other combined NPM1/FLT3 genotype; this difference was statistically significant within the group of high-risk patients (pOS ± SE 83.3 ± 15.2 % versus 33.1 ± 4.7 %; p = 0.0251). This is the first report of the frequencies of these mutations in Argentina. Despite the limited number of patients, a favorable prognosis of AML with genotype NPM1-mutated/FLT3-ITD-negative was confirmed. This is especially relevant within the high-risk group of patients, as it may contribute to the detection of patients with better prognosis, and thus avoid unnecessary treatment intensification.

Evolución y progresos en el tratamiento de la leucemia finfoblastica aguda / Progress in the treatment of acute lymphoblastic leukemia

Muchos avances se han logrado en los últimos 30 años en el tratamiento de la leucemia linfoblástica aguda (LLA) pediática, a nivel mundial y tamibén en nuestro Hospital. Después de su apertura en agosto de 1987 hasta noviembre de 2002 fueron ingresados 989 pacientes con diagnóstico de LLA de los cuales 896 fueron evaluables. Los mismos fueron tratados con 3 protocolos sucesivos: 92 (7 LLa 87), 374 (1 LLA 90) y 430 (1 LLA 96). Las tasas de remisión completa (RC) fueron de 95,6 en el primer protocolo, 94,4 en el segundo y 96,9 en el tercero y un 2,1, 2,9 y 1,8 de los pacientes fallecieron durante la inducción en los respectivos estudios. El principal evento observado fue la recaída de la enfermedad y fallecieron en RC 6 de los pacientes del 7 LLA 87, 4,8 del 1 LLA 90 y 4,3 del 1 LLA 96. La pSLE (EE) fue de 61 (5), 63 (5) y 72 (6), respectivamente, siendo esta diferencia estadísticamente significativa (p=0,0237). El Hospital ha incorporado los métodos diagnósticos necesarios para una mejor estratificicón de los pacientes, y fueron mejoradas las medidas de soporte ofrecidas a los pacientes. Como consecuencia de los logros mencionados se observó una disminución en las tasas de muerte durante la inducción y en RC, con un aumento gradual y significativo de la pSLE. Estos resultados muestran una mejora a lo largo del tiempo y nuestros esfuerzos deben orientarse a una aún mejor optimización de las herramientas diagnósticas, terpéuticas y de soporte para lograr alcanzar los estándares internacionales pra esta población de pacientes.

Morbi mortalidad por infecciones en pacientes con leucemia linfoblástica aguda: recaida en inducción / Infection associated morbidity and mortality in children with relapsed acute limphoblastic leukemia during induction therapy

Los pacientes con Leucemia Linfoblástica Aguda (LLA) recaída reciben quimioterapia (QMT) intensa que produce neutropenia severa y prolongada que condiciona mayor frecuencia de infecciones. Con el fin de evaluar las características clínicas de las infecciones en estos pacientes con neutrepenia y fiebre (NF) luego de la QMT de inducción se realizó un análisis retrospectivo de estos episodios de NF. La QMT de inducción incluyó 10 días de prednisona 100 mg/m2 VO y altas dosis de QMT de 6 días de duración. Recibieron esta QMT 98 pacientes en el período comprendido entre septiembre de 1994 y Diciembre de 2002. De los 96 pacientes evaluables el 73 eran varones y la edad media fue de 110.5 meses. E 28 eran mayores de 12 años. El 64 tenían catéter implantable. el 77 eran eutróficos y el 21 obesos. Presentaron NF 86 pacientes (90). El 29 tuvo sepsis. Todos los episodios de NF cumplieron criterios de alto riesgo. La media de días de internación fue 19.5. El 19 de los niños requirió en Unidad de Cuidados Intensivos (UCI). Recibieron asistencia respiratoria mecánica (ARM) el 16 de los niños. El 52 de los niños tuvo bacteriemia, donde prevalecieron los cocos Gram positivos (29) seguido de bacilos Gram negativos (22). Ochenta y cinco por ciento de los episodios presentaron foco clínico de infección y prevalecieron el foco pulmonar (33.3) y la mucositis oral (32.3). Fallecieron 9 pacientes (9.4). Todas las muertes fueron debidas a sepsis no controlada. La edad mayor a 12 años fue la única variable estadísticamente significtiva relacionada con la mortalidad (OR 6.3, IC 951.4-27.3; p<0.01). La presencia de foco perianal, enteral y el infiltrado pulmonar se asociaron con la presencia de sepsis. Los pacientes con NF luego de la inducción de LLA recaída tienen alta tasa de mortalidad relacionada con la infección, perticularmente la sepsis. En este grupo de pacientes es necesario extremar los cuidados posteriores a la QMT.

Nuevos blancos terapéuticos en leucemia aguda pediatrica: caracterización de las mutaciones del gen FLT3 / Newer therapeutic targets in acute limphoblastic leukemia: characterization of mutations of the gene FLT3

El tratamiento de elección para las leucemias agudas pediátricas es la quimioterapia convencional, que ha permitido obtener tasas de sobrevida que actualmente parecen difíciles de superar. En los últimos años se han intensificado las investigaciones dirigidas a descubrir nuevos blancos terapéuticos, entre los que se encuentra el receptor FLT3. Los blastos leucémicos puede presentar formas mutadas de dicho receptor, siendo las más frecuentes mutaciones internas en tándem (FLT3 ITD) y mutaciones puntuales en la zona de activación (FLT3 ALM). Objetivos: Poner a punto la detección de mutacoines de FLT3, analizar su prevalencia en nuestra población de pacientes con diagnóstico de Leucemia Mieloblástica Aguda (LMA) o de Leucemia Linfoblática Aguda en infantes (LLA I), y evaluar su asociación con parámetros clínicos y de laboratorio. Pacientes y Método: El estudio de las mutaciones se realizó por RT PCR, en un total de 122 pacientes (92 LMA y 30 LLA 1). Resultados: Se detectaron mutaciones en el 15,2 de las LMA y en 10 de las LLA -1. La prevalencia de las FLT3 ITD mostró un aumento gradual con la edad de los pacientes, y la media de edad fue significativamente mayor. Con respecto a asociaciones con recuentos leucocitarios, alteraciones genéticas, subtipos FAB y valor pronóstico, si bien hubo difrencias éstas no furon significtivas. Conclusiones: Este es el primer estuido de mutaciones en FLT3 realizado en población pediátrica en nuestro país. La detección de estas mutaciones permitirá individualizar, en el futuro, a los niños candidatos a recibir drogas inhibidoras de FLT3, actualmente en desarrollo.

Childhood acute lymphoblastic leukemia: prognostic value of initial peripheral blast count in good responders to prednisone.

PURPOSE: To assess the value of initial peripheral blast count in patients with acute lymphoblastic leukemia (ALL) and prednisone good response (PGR). PATIENTS AND METHODS: From January 1990 to December 1995, 403 consecutive patients with newly diagnosed ALL were enrolled in the authors' protocol 1-ALL90-BFM/HPG. Prednisone good response was defined as a blast count of less than 1,000/microL and a prednisone poor response (PPR) as a blast count of at least 1,000/microL, both in peripheral smears, after 7 days of oral prednisone (60 mg/m2 per day) and one intrathecal dose of methotrexate. In the PGR group, patients were divided into two subgroups: patients who had less than 1,000 blasts/microL at diagnosis and those with at least 1,000 blasts/microL at diagnosis. RESULTS: Three-hundred thirty-seven patients (90%) had PGR and 37 had (10%) PPR. At 5-year follow-up, event-free survival estimates were 67 +/- 3.8% and 38 +/- 8% for PGR and PPR, respectively (P = 0.0001). In the PGR group, 114 patients (34%) had an initial blast count of less than 1,000/microL and 223 (66%) had an initial blast count of at least 1,000/microL. The authors compared the clinical and laboratory characteristics of these subgroups at diagnosis and outcome and detected significant differences in white cell count, incidence of T immunophenotype, and presence of mediastinal or spleen enlargement. However, there were no differences in response to induction treatment, death in complete remission, relapses, or event-free survival probability. CONCLUSIONS: In the PGR group, regardless of the initial blast count, both subgroups had the same outcome. The PGR group with an initial blast count of at least 1,000/microL had significantly higher white cell counts. T markers, and mediastinal or spleen enlargement at diagnosis. Response to prednisone is a practical, inexpensive, and good prognostic factor in childhood ALL.

Acute lymphoblastic leukemia presenting as acute hepatic failure in childhood.

We report a 7-year old white girl who was admitted because of acute severe hepatic failure. Her complete blood count revealed pancytopenia and a bone marrow aspiration was consistent with acute lymphoblastic leukemia (ALL). Blasts cells were positive for cytoplasmic CD3 and cell surface T-associated markers. Viral, metabolic, immune and toxic causes for hepatic failure were ruled out. Treatment pre-phase with prednisone was started and liver function tests clearly improved after one-week therapy. However, due to her hepatic insufficiency, daily etoposide was administered orally during 15 days. On day 33 complete remission was achieved and hepatic function was normal, except for an increase in the bilirubin level which normalized on day 72. She received our current treatment for intermediate risk ALL and is still receiving continuation phase therapy, currently, with normal liver function and good tolerance to chemotherapy + 8 months after achieving complete remission.

Good outcome of children with acute myeloid leukemia and t(8;21)(q22;q22), even when associated with granulocytic sarcoma: a report from a single institution in Argentina.

BACKGROUND: The association between t(8;21) and granulocytic sarcoma (GS) is well known, but to the authors' knowledge the prognostic significance of GS in these patients has not been defined clearly. METHODS: Between January 1990 and July 1999 174 children with acute myeloid leukemia were admitted to the study institution. Translocation (8;21) was identified in 20 patients (11.5%). Eighteen patients were evaluable for the current study and 8 presented with GS at the time of diagnosis (GS+). RESULTS: The authors defined two groups of patients: those who were GS+ and those who were GS-. One patient in the GS+ group and two patients in the GS- group died during the induction phase of the study. Complete remission was achieved in seven patients in the GS+ group and eight patients in the GS- group. Two patients developed a recurrence in the GS+ group as did one patient in the GS- group. The event free-survival probability (the standard error) was 58% (18%) in the GS+ group and 70% (14%) in the GS- group. Localization of GS was in only one site in seven patients and at multiple sites in one patient. Patients with an epidural mass received local radiotherapy (one patient) or surgery (two patients). Two of these patients developed paraplegia as sequelae: one patient after surgery and one patient after radiotherapy. One patient with orbital GS received local radiotherapy because of progressive proptosis. The remaining four patients had a complete resolution of the GS with chemotherapy only. CONCLUSIONS: In the current study of patients with t(8;21)(q22;q22), the presence of granulocytic sarcoma was not found to be an adverse prognostic factor. However, careful attention should be paid, especially to patients with an epidural site, to avoid sequelae. Chemotherapy appears to be the optimum treatment for these children.

Childhood acute promyelocytic leukemia: no benefit of all-trans-retinoic acid administered in a short-course schedule.

From January 1990 to August 1997, 29 consecutive patients were treated with newly diagnosed primary acute promyelocytic leukemia (APL) at the authors' Institution. Of these, 27 (16 boys and 11 girls) were evaluable. Median age at diagnosis was 6.3 (range: 1.9-15.7) years. This population was treated with two consecutive protocols: 13 patients were included in the AML-HPG-90 protocol and 14 in the AML-HPG-95. The initial treatment was the same for both protocols: an induction 8-day phase with cytarabine, idarubicin, and etoposide was followed by a consolidation with cyclophosphamide, cytarabine, 6-mercaptopurine, vincristine, doxorubicin, and prednisone. Two courses of intensification with high-dose (HD) cytarabine and etoposide were given in the first study. Only one intensification course was administered in the second study, with HD cytarabine plus idarubicin or etoposide decided by randomization. Complete remission was achieved in 67% (18/27) of cases. Mortality on induction was quite high, 30% (8/27) mainly due to hemorrhages from disseminated intravascular coagulation (DIC). The event-free survival estimate for all patients was 0.47 (SE: 0.1). From April 1994, all-trans-retinoic acid (ATRA) was administered just during the first days of the induction phase (median: 9, range: 2-27) to stop or prevent DIC. Eighteen patients received ATRA and 9 did not. Three patients developed signs of ATRA syndrome during the first days of administration but no one died due to this toxicity. The impact of a short course of ATRA on early control of DIC was studied by analyzing the number of platelet, cryoprecipitate, and fresh frozen plasma transfusions during the induction phase in both groups. No statistical differences in complete remission rate, early mortality, need of transfusion of blood components for DIC, and survival estimates could be established between patients who received ATRA and those who did not. ATRA used in a short-course schedule during induction of APL did not stop early mortality due to DIC. Moreover, survival results did not improve with this method of ATRA usage. Longer periods of ATRA administration during APL therapy are strongly recommended.

Acute trilineage leukemia with monosomy of chromosome 7 following an acute promyelocytic leukemia.

We describe an 8 year old boy who had received chemotherapy for an acute promyelocytic leukemia and developed a secondary leukemia 27 months after the diagnosis of this first malignancy. Blasts cells were positive for cytoplasmic markers CD22, CD3 and myeloperoxidase. Cell surface T and myeloid-associated markers were also detected. Cytogenetic study disclosed monosomy 7. The patient achieved complete remission, but relapsed 15 months later with identical immunophenotypic and cytogenetic findings. Three-lineage commitment is proved by the expression of specific criteria for myeloid, and lymphoid T and B typing. A multipotent immature progenitor must be the target of leukemogenic agents. The prognosis is obviously ominous.

Treatment results in childhood acute lymphoblastic leukemia with a modified ALL-BFM'90 protocol: lack of improvement in high-risk group.

We report results achieved in our institution with an acute lymphoblastic leukaemia risk-oriented treatment trial opened in January 1990 and closed on December 1995. The study was similar to the German ALL-BFM'90, except for using Protocol III for the standard-risk group, 2 g/m2 of methotrexate in Protocol M, and preventive cranial irradiation for the high-risk group only. The high-risk group included mostly patients with prednisone poor initial response and/or adverse cytogenetic features. This analysis included 374 patients, whose mean age was 6 years (range: 1 month-17 years). The overall complete remission rate was 94.4% (353/374) and the 5-year event-free survival (standard error) probability is 64(5)%. The 5-year event-free survival estimates for each risk group were: (1) high-risk group 37(5)%; (2) intermediate-risk group 66(1)%; and (3) standard-risk group 74(4)% (P = 0.0001). There are significantly higher-rates of isolated bone marrow and testicular relapses in the high-risk subset of patients. Our dismal results and the published experience, lead us to conclude that the optimal treatment for these high-risk acute lymphoblastic leukaemia patients is not currently known.

[Translocation t(9;11) in acute childhood lymphoblastic leukemia]. / Traslocación t (9;11) en leucemia linfoblástica aguda en pediatría.

We report a case of a de novo acute lymphoblastic leukaemia (ALL) with t(9;11) (p21;q23) and a novel translocation t(2;8) (p15;q24). The former is characteristic of acute nonlymphoblastic leukaemia (ANLL) and has rarely been detected in ALL. The blasts showed L2 morphology by the French American British (FAB) classification and pre B ALL immunophenotype.

Acute myelogenous leukemia in Down's syndrome: report of a single pediatric institution using a BFM treatment strategy.

Between July 1990 and December 1995, 111 new consecutive pediatric patients with acute myelogenous leukemia (AML) have been treated in our institution. Eleven of them (9.9%) had Down's syndrome (DS), 6 boys and 5 girls. The median age was 22.5 (range 10-40) months. FAB subtypes were the following: M7: 6, M4: 3, and M0: 2. Five of them had previously had myelodysplasia and in 3, all FAB M7, myelofibrosis was detected. This population was treated with two consecutive protocols. Nine patients were included in the AML-HPG-90 protocol and 2 patients in the AML-HPG-95 study, respectively. However, all DS patients in this series received the same treatment. Eight patients achieved complete remission: two patients received two cycles of intensification with high dose (HD) ara-C, and 1 patient, only one cycle; the other 5 were prevented from receiving such therapy because of unacceptable toxicity or death. At 45 months, event-free survival and overall survival estimates were 0.30, S.E. 0.16. Mortality was remarkably high. All deaths (7) were associated with sepsis (5) or pulmonary infection (2). Three deaths occurred before achieving complete remission, 3 patients died during the consolidation phase and 1 died whilst off treatment. No one presented leukemic relapse. We conclude that this AML-BFM treatment strategy is highly toxic to children with DS and AML in our setting. Efforts will be made to improve clinical support and to administer less intensive therapy to this particular pediatric AML subgroup, which, in fact, has a better prognosis than the same non-trisomic population.