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Resumen La participación en programas de evaluación externa de la calidad (PEEC) dirigidos al diagnóstico de enfermedades genéticas permite obtener una medida objetiva del desempeño técnico y analítico de los laboratorios y es un requisito para la acreditación de los laboratorios clínicos bajo la norma ISO 15189. El objetivo de este estudio fue evaluar retrospectivamente el desempeño en los esquemas EMQN (European Molecular Genetics Quality Network) y CF Network (Cystic Fibrosis European Network) en el período 2014-2022. Se participó en un total de 88 esquemas. Se recolectó la información de nuestros puntajes y las medias de los laboratorios participantes en las categorías genotipificación, interpretación y exactitud de la información del paciente/informe. Se informó en forma completa el 90,9% (n=80) de los esquemas. El desempeño en genotipificación mostró puntajes superiores a la media en el 89,3% de los esquemas; 0,8% de los informes correspondieron a falsos negativos. En interpretación, el 66,7% de los esquemas evidenció un desempeño superior a la media y el 33,3% debajo de la media. La exactitud de la información del paciente/informe presentó puntajes superiores a la media en el 97,6% de los esquemas. Se observó una diferencia estadísticamente significativa en el porcentaje de esquemas con puntaje por encima de la media en el año 2022 (10/12 esquemas) respecto al año 2014 (1/6 esquemas) en la categoría interpretación (p=0,0128). En conclusión, la participación regular en PEEC tuvo impacto positivo en la calidad de los estudios y permite realizar mejoras continuas a partir de las recomendaciones sugeridas por estos programas.
Abstract Participation in external quality assessment programmes focused on rare genetic diseases makes it possible to assess the laboratory technical and analytical performance and it is a prerequisite for accreditation according to ISO 15189. The objective of this study was to perform a retrospective evaluation of our performance in the EMQN (European Molecular Genetics Quality Network) and the CF Network (Cystic Fibrosis European Network) programmes in the 2014-2022 period. The laboratory performance on genotyping, interpretation and clerical accuracy and patient identifiers in a total of 88 schemes were assessed. The information of our scores and the mean scores of all participating laboratories in the three categories were collected. A total of 90.9% of the schemes were fully completed. The performance in genotyping showed scores above the mean scores in 89.3% of the schemes; 0.8% of the reports correspond to false negative results. Regarding interpretation category, 66.7% of the schemes presented scores above the mean scores and 33.3% below the mean scores. The clerical accuracy and patient identifiers were above the mean scores in 97.6% of the schemes. A statistically significant difference in the percentage of schemes with a score above the mean for the interpretation category in the year 2022 (10/12 schemes) was observed compared to the year 2014 (1/6 schemes) (p=0.0128). In conclusion, regular participation in external quality assessment programmes had a positive impact on the quality of the studies and allows for continuous improvements based on the recommendations suggested by these programmes.
Resumo A participação em programas de avaliação externa da qualidade (PEECs) voltados para o diagnóstico de doenças genéticas permite obter uma mensuração objetiva do desempenho técnico e analítico dos laboratórios e é requisito para a acreditação dos laboratórios clínicos sob a norma ISO 15189. O objetivo desse estudo foi avaliar retrospectivamente o desempenho nos esquemas EMQN (European Molecular Genetics Quality Network) e CF Network (Cystic Fibrosis European Network) no período 2014-2022. Participou-se em um total de 88 esquemas. Foram coletadas informações de nossos escores e das médias dos laboratórios participantes nas categorias genotipagem, interpretação e precisão da informação do paciente/laudo. 90,9% (n=80) dos esquemas foram informados em sua totalidade. O desempenho na genotipagem apresentou escores acima da média em 89,3% dos esquemas; 0,8% dos laudos corresponderam a falsos negativos. Na interpretação, 66,7% dos esquemas apresentaram desempenho acima da média e 33,3% abaixo da média. A precisão das informações do paciente/laudo apresentou escores acima da média em 97,6% dos esquemas. Observou-se diferença estatisticamente significativa no percentual de esquemas com pontuação acima da média no ano de 2022 (10/12 esquemas) em relação ao ano de 2014 (1/6 esquemas) na categoria interpretação (p=0,0128). Em conclusão, a participação regular em PEECs teve um impacto positivo na qualidade dos estudos e permite fazer melhorias contínuas com base nas recomendações sugeridas por esses programas.
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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.
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OBJECTIVE: To describe the clinical and molecular features of a group of Argentinian pediatric patients with mitochondrial DNA (mtDNA) disorders, and to evaluate the results of the implementation of a classical approach for the molecular diagnosis of mitochondrial diseases. METHODS: Clinical data from 27 patients with confirmed mtDNA pathogenic variants were obtained from a database of 89 patients with suspected mitochondrial disease, registered from 2014 to 2020. Clinical data, biochemical analysis, neuroimaging findings, muscle biopsy and molecular studies were analyzed. RESULTS: Patients were 18 females and 9 males, with ages at onset ranging from 1 week to 14 years (median = 4 years). The clinical phenotypes were: mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome (n = 11), Leigh syndrome (n = 5), Kearns-Sayre syndrome (n = 3), Chronic Progressive External Ophthalmoplegia (n = 2), Leber hereditary optic neuropathy (n = 2), myoclonic epilepsy associated with ragged-red fibers (n = 1) and reversible infantile myopathy with cytochrome-C oxidase deficiency (n = 3). Most of the patients harbored pathogenic single nucleotide variants, mainly involving mt-tRNA genes, such as MT-TL1, MT-TE and MT-TK. Other point variants were found in complex I subunits, like MT-ND6, MT-ND4, MT-ND5; or in MT-ATP6. The m.13513G > A variant in MT-ND5 and the m.9185 T > C variant in MT-ATP6 were apparently de novo. The rest of the patients presented large scale-rearrangements, either the "common" deletion or a larger deletion. CONCLUSIONS: This study highlights the clinical and genetic heterogeneity of pediatric mtDNA disorders. All the cases presented with classical phenotypes, being MELAS the most frequent. Applying classical molecular methods, it was possible to achieve a genetic diagnosis in 30% of the cases, suggesting that this is an effective first approach, especially for those centers from low-middle income countries, leaving NGS studies for those patients with inconclusive results.
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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.
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IMPORTANCE: Fatal metastatic relapse may occur in children with retinoblastoma and high-risk pathologic features (HRPFs). Minimal dissemination (MD) may be an additional tool for risk estimation. The use of cone-rod homeobox (CRX) transcription factor messenger RNA for MD evaluation in metastatic retinoblastoma was previously reported, but no data in nonmetastatic cases with HRPFs are available. OBJECTIVES: To evaluate whether MD is detectable in patients with nonmetastatic retinoblastoma and to assess its prognostic effect on disease-free survival (DFS). DESIGN, SETTING, AND PARTICIPANTS: This single-institution cohort study of patients with nonmetastatic retinoblastoma and HRPFs used prospectively defined inclusion criteria and a sampling strategy to procure bone marrow (BM) and cerebrospinal fluid (CSF) samples from May 1, 2007, through October 31, 2013. Median follow-up was 38 months (range, 8-89 months). Survival analysis was closed in December 2015, and no further updates were made after that point. INTERVENTIONS: The study evaluated CRX messenger RNA by quantitative polymerase chain reaction in BM and CSF at diagnosis and follow-up. In 14 patients, GD2 synthase was used instead of CRX for CSF evaluation. Patients were treated under uniform guidelines. MAIN OUTCOMES AND MEASURES: Metastatic relapse. RESULTS: The study included 96 children (median age at study inclusion, 26 months; range, 1-168 months; 46 male [47.9%]; 50 female [52.1%]) with nonmetastatic retinoblastoma and HRPFs (isolated massive choroidal invasion in 14, postlaminar optic nerve invasion in 51 [26 with concomitant massive choroidal and 13 with scleral invasion], 12 with scleral invasion without postlaminar optic nerve invasion, and 7 with tumor at the resection margin of the optic nerve) were evaluated at the time of primary or secondary enucleation. Minimal dissemination was detected in 9 patients (7 BM samples and 2 CSF samples) and was associated with extension beyond the resection margin of the optic nerve and scleral involvement, but only the former was independently associated (adjusted odds ratio, 57.0; 95% CI, 4.8-678.2; P = .001). In addition, MD occurred in 8 of the 43 International Intraocular Retinoblastoma Classification group E eyes with glaucoma (18.6%) and in 8 of 80 (10%) and 1 of 16 children (6.3%) who underwent primary or secondary enucleation, respectively. Children with MD had a 3-year DFS of 0.78 compared with 0.98 in those without MD (95% CI for the difference in DFS, 0.17-0.23; P = .004). CONCLUSIONS AND RELEVANCE: These findings identified a high-risk population of children with retinoblastoma and HRPFs with MD. Because the number of events was small, these results, which suggest that children with International Intraocular Retinoblastoma Classification group E retinoblastoma and glaucoma have a higher risk of MD at diagnosis, should not be considered definitive at this time.
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Estadiamento de Neoplasias , Neoplasias da Retina/diagnóstico , Retinoblastoma/diagnóstico , Argentina/epidemiologia , Biópsia , Pré-Escolar , Intervalo Livre de Doença , Feminino , Seguimentos , Humanos , Lactente , Recém-Nascido , Masculino , Prognóstico , Estudos Prospectivos , Retina/patologia , Neoplasias da Retina/mortalidade , Retinoblastoma/mortalidade , Fatores de Risco , Análise de Sobrevida , Taxa de Sobrevida/tendências , Fatores de TempoRESUMO
The association between mature-B phenotype and MLL abnormalities in acute lymphoblastic leukemia (ALL) is a very unusual finding; only 14 pediatric cases have been reported so far. We describe the clinical and biological characteristics and outcome of five pediatric cases of newly diagnosed B lineage ALL with MLL abnormalities and mature immunophenotype based on light chain restriction and surface Ig expression. Blasts showed variable expression of CD10/CD34/TdT. MLL abnormalities with no MYC involvement were detected in all patients by G-banding, FISH, and/or RT-PCR. Three patients were treated according to Interfant protocol, one to ALLIC-09, and one received B-NHL-BFM-2004. All patients achieved complete remission and three of them relapsed. Despite the small cohort size, it could be postulated that B lineage ALL with MLL abnormalities and mature phenotype is a distinct entity that differs both from the typical Pro B ALL observed in infants and mature B-ALL with high MYC expression.
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Rearranjo Gênico , Proteína de Leucina Linfoide-Mieloide/genética , Fenótipo , Leucemia-Linfoma Linfoblástico de Células Precursoras B/diagnóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Medula Óssea/metabolismo , Medula Óssea/patologia , Bandeamento Cromossômico , Progressão da Doença , Evolução Fatal , Feminino , Transplante de Células-Tronco Hematopoéticas , Humanos , Imunofenotipagem , Lactente , Masculino , Gradação de Tumores , Leucemia-Linfoma Linfoblástico de Células Precursoras B/terapia , Translocação Genética , Transplante Homólogo , Resultado do TratamentoRESUMO
The aim of this study was to evaluate the influence of the most common genetic variants in methylenetetrahydrofolate reductase (MTHFR), thiopurine methyltransferase (TPMT) and glutathione-S-transferases (GSTs) on the outcome of acute lymphoblastic leukemia (ALL) treatment in Argentinean children. Two hundred and eighty-six patients with ALL treated with two Berlin-Frankfurt-Münster (BFM)-based protocols were analyzed. Ten genetic variants were studied. Toxicity was evaluated during the consolidation phase. Children who received 2 g/m(2)/day of methotrexate and carried at least one 677T allele in MTHFR showed an increased risk of developing severe leukopenia (p = 0.004) and neutropenia (p = 0.003). Intermediate-risk (IR) patients with a heterozygous TPMT genotype had a higher probability of event-free survival than those with a wild-type genotype. Genotyping of MTHFR polymorphisms might be useful to optimize consolidation therapy, reducing the associated severe hematologic toxicity. Further studies are necessary to establish the usefulness of MTHFR and TPMT variants as additional markers to predict outcome in the IR group.