Pediatric Hodgkin lymphoma in 2 South American series: a distinctive epidemiologic pattern and lack of association of Epstein-Barr virus with clinical outcome.

Hodgkin lymphoma (HL) shows a bimodal distribution with a first peak in developing countries during childhood. The causative role and prognostic significance of Epstein-Barr virus (EBV) association in patients with HL is controversial. Our aim was to perform a comparative study of EBV association in 2 Latin American pediatric HL series, and to correlate it with patient's survival. Epstein-Barr encoded RNAs in situ hybridization and latent membrane protein 1 immunohistochemistry were performed on formalin-fixed, paraffin-embedded HL biopsies from 176 pediatric patients from 2 public institutions from Argentina and Southeast Brazil. Mixed cellularity subtype was prevalent in Argentine HL (Arg HL) (52%) and nodular sclerosis subtype in Brazilian HL (BR HL) (83%). EBV expression was detected in 52% of cases, namely 54% Arg HL and 48% Br HL. EBV was significantly associated with mixed cellularity subtype in both populations. In Arg HL, EBV positivity was significantly higher in patients

Decreased serum inhibin B/FSH ratio as a marker of Sertoli cell function in male survivors after chemotherapy in childhood and adolescence.

OBJECTIVE: Inhibin B produced by Sertoli cells may be an important marker of seminiferous tubule function in patients treated with chemotherapy (CT). The aim of this study was to evaluate the inhibin B/FSH ratio to detect male gonadal dysfunction in cancer survivors treated in childhood and adolescence. PATIENTS: Twenty-one male patients (group A) treated with 6-10 courses of CT for Hodgkin's disease during childhood and adolescence were examined 3-11 years after the conclusion of treatment. Twenty healthy young men (18-23 years old) were used as controls (group B). METHODS: Serum samples for the determination of inhibin B, follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone (T), sex hormone-binding globulin (SHBG) and semen for analysis were collected. RESULTS: The median testicular volume of patients of group A was lower than those of group B (p = 0.001) and a positive correlation was found between testicular size and sperm count (r = -0.5, p = 0.01). Semen analysis revealed azoospermia in 11 patients, severe oligospermia in four and normal sperm count in three. No significant difference was found in the median of T, LH, SHBG, inhibin B concentrations and T/LH ratio between the groups. Serum inhibin B was correlated with the serum FSH levels (r = -0.5, p = 0.02). Median FSH was significantly higher (p = 0.0001), and median inhibin B/FSH ratio was significantly lower in group A than in controls (p = 0.0002), but the inhibin B/FSH ratio was higher in the patients with normal sperm count than in those with oligospermia (p = 0.00004). CONCLUSIONS: These results show that the cytotoxic effects of CT cause severe damage to the germinal epithelium with subtle effects on Sertoli cells. To assess Sertoli cell function in men with primary testicular damage after treatment with CT in childhood and adolescence, the inhibin B level needs to be interpreted in the context of the circulating FSH, especially when normal FSH levels are observed.

Treatment of children with B-cell non-Hodgkin's lymphoma in developing countries: the experience of a single center in Brazil.

PURPOSE: To treat non-Hodgkin's B-cell lymphoma (B-NHL) in children with manageable toxicity-related morbidity and without any decrease in survival. PATIENTS AND METHODS: Between January 1998 and April 2003, 53 consecutive patients (age 16 years or less) from a single institution were enrolled. The patients were stratified by risk factors (stage and LDH level) and treated with a BFM 86/90 (Berlin-Frankfurt-Münster)-based protocol with reduction of the methotrexate dose from 5 mg/m to 2 mg/m. RESULTS: The mean age of the patients was 6 years (range 1-16 years). Seventy-two percent of the patients had lymphomas classified as Burkitt type, 11% as diffuse large cell lymphoma, and 6% as Burkitt-like lymphoma, and 11% were not classified. At a median follow-up of 35 months, 44 patients (83%) survived in complete remission. The event-free survival rate for all patients was 78% (SE = 0.07): 100% (SE = 0.0) for stage I/II patients and 74% (SE = 0.08) for stage III/IV patients. Six patients suffered initial treatment failure and one patient relapsed, all of whom died. There was only one death from sepsis related to treatment. CONCLUSIONS: This strategy was very effective for treating B-NHL in a developing country. The results were comparable to those of the BFM 90 study and other contemporary groups and represented an increase in the cure rates in childhood B-NHL in Brazil.

A child with Philadelphia positive (Ph+)-acute leukemia with myeloid morphology: one case of stem cell origin.

Philadelphia positive (Ph+) acute myeloid leukemia (AML) is a rare and heterogeneous condition, mainly reported in adults, associated to poor prognosis and unfavorable response to therapy. Here we report clinical and laboratory findings in an 8-year-old patient diagnosed with Ph+ acute leukemia with myeloid (FAB M4) morphology. The patient consistently expressed variable levels of m-bcr, e1a2 transcripts during a 42-month follow-up after two different stem cell transplantation protocols. An immunophenotypic switch was documented, from a mixed, myeloid-lymphoid lineage to a full lymphoid phenotype following stem cell transplants, in association with an immature B-cell gene rearrangement profile and clonal instability during clinical progression. This report indicates a stem cell origin as previously suggested for Ph+ AML.

Geographic variation in Epstein-Barr virus-associated Burkitt's lymphoma in children from Brazil.

In developing countries, BL has a strong association with EBV infection during childhood. In South America, the data have shown an EBV association intermediate between that reported in the United States (30%) and that in equatorial Africa (95%). Early age at EBV infection and lower socioeconomic status have been related to increased EBV-associated BL in developing countries. In Brazil, there are not enough data on childhood BL related to EBV infection. Our aim was to evaluate the clinicopathologic features and EBV association of 44 children with NHL from the state of Rio de Janeiro, situated in the southeast of Brazil. EBV was detected using RNA in situ hybridization in 36 biopsy specimens. DNA from fresh tumor samples and from paraffin-embedded tissues of patients were analyzed by PCR, in which the first reaction included primers for an EBNA-2 common region while the nested reaction amplified the region discriminating between EBV types 1 and 2 in separate reactions. EBV was detected in 21 of 29 BLs (72%), and type 1 virus infected the majority of EBV-positive BLs (18/21). There was a trend for younger age in children with EBV-positive BL compared to EBV-negative BL (median age 4 compared to 6 years, respectively; p = 0.056). Our study confirmed that in the southeast of Brazil BL had an intermediate association with EBV. A higher rate of EBV-associated BL was described in the northeast of Brazil. These differences are probably related to regional socioeconomic status. In conclusion, our study suggests that early infection with EBV in the background of a low socioeconomic condition associated with other environmental factors could contribute to BL in Brazil.

DNA sequence profile of TP53 gene mutations in childhood B-cell non-Hodgkin's lymphomas: prognostic implications.

OBJECTIVES: The TP53 gene encodes a nuclear protein implicated in the regulation of the cell cycle, DNA repair, and apoptosis. TP53 mutations and other alterations have been described in numerous types of tumors, and some of these have been associated with poor prognosis. The aim of this study was to characterize TP53 mutations in childhood B non-Hodgkin's lymphoma, their correlation with clinical prognostic factors and response to therapy. PATIENTS AND METHODS: Samples from 49 children with B non-Hodgkin's lymphoma were examined for TP53 alterations by single-strand conformation polymorphism analysis (SSCP) of exons 5-9, direct sequencing and by p53 immunohistochemistry. RESULTS: Mutations of TP53 were detected in 11 of 49 (22.5%) patients and more specifically in 20% of Burkitt's lymphoma. The sequence analysis showed missense mutations in 10 cases and an insertion mutation in one case. Mutations of the transition type occurred more frequently than transversions (seven of 11). Analysis of the spectrum of single-nucleotide substitutions showed a 30% frequency of transition mutations in CpG dinucleotide sequences. The overall frequency of p53 immunostaining positivity was 36% (15 of 41). There was a very good agreement between protein expression and the presence of TP53 mutation (P=0.0005). No significant correlation was found regarding age, gender, clinical stage and LDH level and TP53 mutations. Comparison of EFS curves using the log-rank test were also not significant. However, the analysis of the effects of mutations on the core p53 structure identified biological and biochemical mutants with phenotypes probably related to different response to chemotherapy. CONCLUSIONS: Our data suggest that some types of mutants can alter the protein distinctly and may be associated with a more aggressive phenotype. In addition, the impact of TP53 mutations on response to therapy may also be influenced by disruption of other genes.

Alemtuzumab (Campath-1H) para tratamento da leucemia linfóide crônica / Alemtuzumab (Campath-1H) in chronic lymphocytic leukemia

O CAMPATH-1H é um anticorpo monoclonal quimérico dirigido contra o CD 52, antígeno expresso na superfície das células linfóides malignas ou normais, macrófagos, monócitos, eosinófilos e algumas células epiteliais. Este anticorpo tem sido usado no tratamento de linfomas não-Hodgkin, doenças auto-imunes, esquemas de condicionamento para transplante de medula óssea e particularmente na leucemia linfóide crônica (LLC). Os estudos de fase II em LLC revelam um índice de resposta global em torno de 33 por cento, com 4 por cento a 31 por cento de respostascompletas, em casos de doença refratária ou recidivada. As principais complicações observadas foram relacionadascom a infusão venosa do medicamento (febre, calafrios, náusea e hipotensão) e infecções oportunísticas. Atualmente está em andamento um estudo de fase III, com o objetivo de comparar as eficácias do CAMPATH-1H e clorambucil para pacientes com LLC.

Correlaçäo entre a expressäo celular do CD44 e formas tumorais das leucemias linfoblásticas / Correlation between the cellular expression of CD44 and the forms of acute lymphoblastic

O CD44 é uma molécula de adesäo que se expressa em linfócitos-B e T, participa na mediaçäo de adesäo destas células e dos componentes da matriz extracelular e na adesäo a células endoteliais vasculares. A proposta deste estudo foi a de investigar a expressäo celular do CD44 em 108 pacientes portadores de leucemias linfoblásticas (57 leucemias linfóides agudas de linhagem B e 51 de células-T), através de uma metodologia que inclui a análise citomorfológica e imunofenotipagem, com um painel de anticorpos monoclonais detectados pelas técnicas da imunoperoxidase conjugada, e imunofluorescência com análise por citometria de fluxo. Inicialmente, investigamos a correlaçäo do CD44 com as distintas fases de diferenciaçäo celular destas leucemias, determinadas pela expressäo antigênica. Em seguida, investigamos a correlaçäo desta molécula com os achados clínico-patológicos, como a presença de massas tumorais, adenomegalias, infiltraçäo de células leucêmicas no sistema nervoso central e em outros órgäos, além da presença de células blásticas no sangue periférico. Paralelamente ao estudo das leucemias, também investigamos a expressäo de CD44 em linfócitos do sangue periférico oriundos de 11 indivíduos sadios. A expressäo de CD44 foi positiva em 83 casos (76,8 porcento) das leucemias linfóides agudas, sendo 46 casos (80,7 porcento) das LLA de linhagem B, e em 37 casos (72,5 porcento) de LLA de células-T. Nos quatro subgrupos que compöem as LLA de linhagem B, observamos a expressäo desta molécula em dois casos (66,7 porcento) das LLA do tipo null; em 34 casos (77,3 porcento) das LLA do tipo comum e em todos os casos de LLA pré-B (cu+) e LLA-B (Smlg+). Já nas LLA de células-T, a expressäo do CD44 mostrou-se variável nos três subgrupos que compöem estas leucemias. No subgrupo I (LLA pré-T), todos os nove casos (100 por cento) foram CD44 positivos; nos 14 casos do Subgrupo II (LLA-T intermediária), quatro casos (28,6 porcento) foram CD44 positivos e no Subgrupo III (LLA-T-medular) o CD44 foi positivo em 24 casos (85,7 porcento). A correlaçäo da expressäo de CD44 com o perfil...

Importância da aplicação de anticorpos monoclonais no diagnóstico laboratorial das leucemias linfóides agudas / The importance to application of monoclonal antibodies in laboratorial diagnostic of lymphoblastic leukemia

Os autores realizaram um estudo em 126 pacientes portadores de leukemia linfóide aguda (LLA) antes do tratamento, com metodologias que incluiu a análise citomorfológica e imunofenotipagem com painel de anticorpos monoclonais (AC.Mo.) específico para leucemias agudas com CD1a, CD2, CD3, CD4, CD7, CD8, CD10, CD13, CD14, CD19, CD22, CD34, anti IgM, antikappa, anti lambda. Anti cadeia mu e anti TdT, através de técnicas como a imunoiperoxidase e citometria de fluxo. Paralelaamente também foram investigadas informações referentes aos pacientes com a idade e sexo, aqssim como dados clínicos e laboratoriais dentre os quais a presença de massas tumorais, linfadenopatia, hepatomegalia, esplenomegalia, infiltração leucêmica no sistema nervoso central (SNC) e contagem de células blásticas no sangue periférico. Os resultados demonstraram que 71 casos (56,7%) foram de LLA de linhagem B (Null, comum, pré-B e B) e 55 LLA de Células T (pré-T, T-intermediária e T-medular). Relacionando-se estes dados com o sexo, observou-se que o sexo masculino foi o mais acometido pela doença, independente da classificação imunológica. Correlacionando-se a idade com os subtipos imunológicos, observou-se que as LLAs de linhagem B foram mais freqüentes em crianças (idade  que 15 anos) ao passo que as LLAs de Células T estiveram mais presentes em indivíduos adultos. A freqüência da r elação destas imunofenotipagens com os subtipos morfológicos da classificação FAB apresentaram uma correlação direta entre o subgrupo L3 e LLA de células B, ao passo que os subgrupos L1 e L2 correlacionaram-se mais freqüentemente com as LLA pré-B e T respectivamente. A análise da correlação entre a imunofenotipagem e o perfil clínico patológico destas LLA demonstraram que as LLA de Células T estavam mais associadas com formas tumorais da doença com uma maior incidência de linfadenopatias, hepatomegalias, esplenomegalias, massas tumorais e infiltração no SNC, apresentando também uma maior contagem de células blásticas no sangue periférico que os demais subgrupos. Finalizando, estes dados, sugerem que a imunofenotipagem é uma importante metodologia no diagnóstico, na monitoração da avaliação prognóstica e na determinação dos mecanismos de evolução patológica das leucemias linfóides agudas.

Meningite por Listeria monocytogenes em um caso de doença de Hodgkin / Meningitis of Listeria monocytogenes in the case Hodgkin's disease

A Listeria monocytogenes constitui uma importante causa de bacteriemia e meningite em pacientes imunossuprimidos 1, 2, 3. Trata-se de um bacilo gram-positivo, que cresce facilmente na maioria dos meios de cultura. Ganhou seu nome devido a sua habilidade de produzir importante monocitose em coelhos. A maioria dos casos de infecçäo por Listeria monocytogenes têm sido reportados em pacientes imunossuprimidos, principalmente naqueles com diminuiçäo da imunidade celular, resultante da presença de doença maligna linforreticular ou em uso de drogas quimioterápicas. Neste trabalho, nós descreveremos um caso de meningite por Listeria monocytogenes, ocorrido em nosso hospital, em um paciente com Doença de Hodgkin. Fazemos uma revisäo da literatura e discutimos a eficácia dos esquemas terapêuticos empregados