RESUMEN
Extranodal natural killer/T-cell lymphoma, nasal type (NK/TCL) is more prevalent in Asia and in some areas of South and Central America, but it is rarely seen in the United States and Europe. In this study, a series of 122 cases of NK/TCL from Brazil was analyzed with respect to clinicopathologic features. Clinical characteristics and geographic distribution were evaluated in 97 cases of nasal/nasopharyngeal region and 23 cases in extranasal sites including 6 nodal cases. Clinical staging and follow-up information was available in a subset of 21 patients. All cases harbored Epstein-Barr virus (EBV), 95% and 85% expressed cytoplasmic CD3 and CD56, respectively, and all cases were positive for at least 1 marker for cytotoxic granules. The global distribution of EBV subtypes showed predominance of strain subtype A, 89%, and subtype B, 11%. No dual infections were detected. TCR-γ TCR-gene rearrangement was observed in 7 cases; all of them extranodal. Three of TCR-γ(+) cases showed EBV subtype A. Two TCR-γ(+)/CD56(+) cases showed EBV subtype B. Geographic distribution of NK/TCL showed higher frequency in the southeast and northeast regions of Brazil. Striking differences among geographic regions were seen with the vast majority of EBV subtype B (86%) occurring in the south and southeast regions.
Asunto(s)
Herpesvirus Humano 4/clasificación , Linfoma Extranodal de Células NK-T/virología , Linfoma de Células T/virología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Brasil/epidemiología , Distribución de Chi-Cuadrado , Niño , ADN Viral/aislamiento & purificación , Femenino , Reordenamiento Génico de la Cadena gamma de los Receptores de Antígenos de los Linfocitos T , Genes Codificadores de la Cadena gamma de los Receptores de Linfocito T , Herpesvirus Humano 4/genética , Humanos , Inmunohistoquímica , Hibridación in Situ , Estimación de Kaplan-Meier , Ganglios Linfáticos/patología , Ganglios Linfáticos/virología , Linfoma Extranodal de Células NK-T/genética , Linfoma Extranodal de Células NK-T/mortalidad , Linfoma Extranodal de Células NK-T/patología , Linfoma de Células T/genética , Linfoma de Células T/mortalidad , Linfoma de Células T/patología , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Reacción en Cadena de la Polimerasa , Pronóstico , Características de la Residencia , Estudios Retrospectivos , Tasa de Supervivencia , Factores de Tiempo , Análisis de Matrices Tisulares , Adulto JovenRESUMEN
Composite lymphomas are rare and defined as hematopoietic neoplasms with more than 1 malignant lymphomatous clone showing different phenotypic features. Of all possible combinations between non-Hodgkin lymphomas, B cell or T cell, and Hodgkin lymphoma, the least frequent are the ones combining T-cell non-Hodgkin lymphoma and classic Hodgkin lymphoma. We report a case of a 55-year-old woman with cervical and mediastinal lymphadenopathy, fever, weight loss, and night sweats. A cervical lymph node biopsy revealed a composite lymphoma with classic Hodgkin lymphoma and peripheral T-cell lymphoma components. The bone marrow was not involved. The patient refused treatment and died of disease progression 2 months after diagnosis. The biopsied lymph node showed 2 distinct populations, one composed of large cells including typical Reed-Sternberg cells and their variants, with expression of CD30, CD15, PAX5, and LMP-1. The other component was more abundant and comprised polymorphic medium-sized cells with convoluted nuclei; CD3, CD5, CD2, and CD4 expression; and negativity for CD30, cytotoxic granules, and B-cell markers. Epstein-Barr virus DNA of subtype A was identified only in the Hodgkin cells. Clonal T-cell receptor gamma and beta gene rearrangements were detected in the T-cell component, whereas monoclonal immunoglobulin H gene rearrangement was found in the Hodgkin cells.
Asunto(s)
Herpesvirus Humano 4 , Enfermedad de Hodgkin/patología , Linfoma de Células T Periférico/patología , Neoplasias Primarias Múltiples/diagnóstico , Femenino , Reordenamiento Génico , Reordenamiento Génico de la Cadena beta de los Receptores de Antígenos de los Linfocitos T , Reordenamiento Génico de la Cadena gamma de los Receptores de Antígenos de los Linfocitos T , Enfermedad de Hodgkin/diagnóstico , Enfermedad de Hodgkin/virología , Humanos , Cadenas Pesadas de Inmunoglobulina/genética , Ganglios Linfáticos/patología , Linfoma de Células T Periférico/diagnóstico , Persona de Mediana Edad , Células de Reed-SternbergRESUMEN
OBJETIVO: Determinar a utilidade, na prática rotineira, da análise da clonalidade dos linfócitos T e B nos tecidos pulmonares por reação em cadeia da polimerase no diagnóstico das doenças linfoproliferativas pulmonares. MÉTODOS: Avaliaram-se, mediante análise imunohistoquímica e rearranjo molecular dos genes, 8 casos de pneumonia intersticial linfocítica (PIL) e 7 casos de doenças linfoproliferativas pulmonares. RESULTADOS: Todos os 8 casos de PIL expressaram imunocoloração moderada a forte para CD3, em contraste com apenas 2 casos de linfoma e 1 caso de pseudolinfoma. Rearranjo gênico foi detectado em 4 de 8 casos de PIL, o que mudou o diagnóstico de PIL para linfoma, indicando, assim, a importância da detecção de rearranjo gênico em casos de PIL. Nesta situação, rearranjo gênico usando-se os pares de primers VH/JH e Vgama11/Jgama12 foi detectado em 3 e 1 casos de PIL, respectivamente, e não foram detectadas anormalidades gênicas usando-se as pares Dbeta1/Jbeta2 e Vgama101/Jgama12. Uma associação positiva foi detectada entre a intensidade de imunoexpressão CD20 e CD68 e rearranjo gênico usando-se o par de primers VH/JH. Antes do rearranjo gênico, 4 pacientes com PIL morreram rapidamente, enquanto que, após o rearranjo gênico, apenas 1 paciente com PIL morreu. CONCLUSÕES: A detecção de células B e T monoclonais por imunofenotipagem e reação em cadeia da polimerase mostrou impacto no diagnóstico de linfomas pulmonares em pacientes previamente diagnosticados com PIL. Portanto, imunofenotipagem e reação em cadeia da polimerase devem ser incluídas como métodos de 'padrão ouro' na rotina diagnóstica.
OBJECTIVE: To determine the usefulness, in routine practice, of using polymerase chain reaction to analyze B and T lymphocyte clonality in pulmonary tissue as a tool for the diagnosis of pulmonary lymphoproliferative disorders. METHODS: Immunohistochemistry and molecular gene rearrangement analysis were performed in order to assess 8 cases of lymphoid interstitial pneumonia (LIP) and 7 cases of pulmonary lymphoproliferative disorders. RESULTS: All 8 cases of LIP presented moderate to strong immunostaining for CD3, compared with only 2 cases of lymphoma and 1 case of pseudolymphoma (p = 0.02). Gene rearrangement was detected in 4 of the 8 cases, which changed the diagnosis from LIP to lymphoma, showing the importance of gene rearrangement detection in cases of LIP. In this situation, gene rearrangement using the VH/JH and Vgamma11/Jgamma12 primer pairs was detected in 3 cases and 1 case, respectively, and no gene abnormalities were found using the Dbeta1/Jbeta2 and Vgamma101/Jgamma12 primer pairs in any of the cases. A significant positive association was found between the intensity of CD20 and CD68 expression and gene rearrangement using the VH/JH primer pair. Prior to the gene rearrangement, 4 patients with LIP died quickly, whereas only one patient with LIP died after the gene rearrangement. CONCLUSIONS: Detection of monoclonal B and T cells by immunophenotyping and polymerase chain reaction had an impact on the diagnosis of pulmonary lymphomas in patients previously diagnosed with LIP. Therefore, immunophenotyping and polymerase chain reaction should be used as 'gold standard' techniques in routine practice.
Asunto(s)
Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Preescolar , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reordenamiento Génico , Inmunofenotipificación , Enfermedades Pulmonares Intersticiales/inmunología , Neoplasias Pulmonares/inmunología , Linfoma/inmunología , Antígenos CD/análisis , Estudios de Casos y Controles , Diagnóstico Diferencial , Cartilla de ADN , Estudios de Factibilidad , Reordenamiento Génico de Cadena Pesada de Linfocito B/genética , Reordenamiento Génico de Cadena Pesada de Linfocito B/inmunología , Reordenamiento Génico de la Cadena gamma de los Receptores de Antígenos de los Linfocitos T/genética , Reordenamiento Génico de la Cadena gamma de los Receptores de Antígenos de los Linfocitos T/inmunología , Enfermedades Pulmonares Intersticiales/diagnóstico , Enfermedades Pulmonares Intersticiales/genética , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/genética , Tejido Linfoide/patología , Linfoma/diagnóstico , Linfoma/genética , Trastornos Linfoproliferativos/diagnóstico , Trastornos Linfoproliferativos/genética , Trastornos Linfoproliferativos/inmunología , Reacción en Cadena de la Polimerasa , Seudolinfoma/diagnóstico , Seudolinfoma/genética , Seudolinfoma/inmunología , Estudios RetrospectivosRESUMEN
OBJECTIVE: To determine the usefulness, in routine practice, of using polymerase chain reaction to analyze B and T lymphocyte clonality in pulmonary tissue as a tool for the diagnosis of pulmonary lymphoproliferative disorders. METHODS: Immunohistochemistry and molecular gene rearrangement analysis were performed in order to assess 8 cases of lymphoid interstitial pneumonia (LIP) and 7 cases of pulmonary lymphoproliferative disorders. RESULTS: All 8 cases of LIP presented moderate to strong immunostaining for CD3, compared with only 2 cases of lymphoma and 1 case of pseudolymphoma (p = 0.02). Gene rearrangement was detected in 4 of the 8 cases, which changed the diagnosis from LIP to lymphoma, showing the importance of gene rearrangement detection in cases of LIP. In this situation, gene rearrangement using the VH/JH and Vgamma11/Jgamma12 primer pairs was detected in 3 cases and 1 case, respectively, and no gene abnormalities were found using the Dbeta1/Jbeta2 and Vgamma101/Jgamma12 primer pairs in any of the cases. A significant positive association was found between the intensity of CD20 and CD68 expression and gene rearrangement using the VH/JH primer pair. Prior to the gene rearrangement, 4 patients with LIP died quickly, whereas only one patient with LIP died after the gene rearrangement. CONCLUSIONS: Detection of monoclonal B and T cells by immunophenotyping and polymerase chain reaction had an impact on the diagnosis of pulmonary lymphomas in patients previously diagnosed with LIP. Therefore, immunophenotyping and polymerase chain reaction should be used as 'gold standard' techniques in routine practice.
Asunto(s)
Reordenamiento Génico , Inmunofenotipificación , Enfermedades Pulmonares Intersticiales/inmunología , Neoplasias Pulmonares/inmunología , Linfoma/inmunología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Antígenos CD/análisis , Estudios de Casos y Controles , Preescolar , Cartilla de ADN , Diagnóstico Diferencial , Estudios de Factibilidad , Femenino , Reordenamiento Génico de Cadena Pesada de Linfocito B/genética , Reordenamiento Génico de Cadena Pesada de Linfocito B/inmunología , Reordenamiento Génico de la Cadena gamma de los Receptores de Antígenos de los Linfocitos T/genética , Reordenamiento Génico de la Cadena gamma de los Receptores de Antígenos de los Linfocitos T/inmunología , Humanos , Enfermedades Pulmonares Intersticiales/diagnóstico , Enfermedades Pulmonares Intersticiales/genética , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/genética , Tejido Linfoide/patología , Linfoma/diagnóstico , Linfoma/genética , Trastornos Linfoproliferativos/diagnóstico , Trastornos Linfoproliferativos/genética , Trastornos Linfoproliferativos/inmunología , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Seudolinfoma/diagnóstico , Seudolinfoma/genética , Seudolinfoma/inmunología , Estudios RetrospectivosRESUMEN
Hepatosplenic gammadelta T-cell lymphoma (HSTL) is a clinicopathological entity associated with an immunocompromised status in approximately 25% of patients. Herein is described a case of HSTL in a 53-year-old Brazilian man with seven previous malaria infections, initially misdiagnosed as a hyperreactive splenomegaly due to chronic malaria. A characteristic lymphoid infiltrate was observed in spleen, liver and bone marrow sinusoids/sinuses. Neoplastic cells had a CD45RO+, CD2+, CD7+, CD3+, CD5-, CD8+, CD56+, perforin+, FasL-negative, T-cell receptor (TCR)alphabeta-negative, TCRgammadelta+ profile. Analyses of gamma and delta TCR rearrangements confirmed diagnosis of gammadelta T-cell lymphoma by detecting VgammaI/Vdelta1-Jdelta1 clonal rearrangements. Sensitive polymerase chain reaction (PCR) for Plasmodium falciparum, Epstein-Barr virus and herpesvirus-8 failed to demonstrate infection. The disease progressed to a fatal outcome following cutaneous infiltration and leukemic proliferation. The authors also comment on the association of lymphoma and infection, focusing on PCR diagnosis of TCRgamma and delta clonal rearrangements and the presumed pathogenic events leading to HSTL in the context of chronic malaria infection. Initial lymphomagenic stages might not be direct consequences of antigenic stimulation of Vdelta1 T-cells, but might depend on interactions between gammadelta T and B cells during cooperative or regulatory responses to Plasmodium sp.
Asunto(s)
Neoplasias Hepáticas/patología , Linfoma de Células T/patología , Malaria/patología , Receptores de Antígenos de Linfocitos T gamma-delta/biosíntesis , Neoplasias del Bazo/patología , ADN de Neoplasias/análisis , Resultado Fatal , Reordenamiento Génico de la Cadena delta de los Receptores de Antígenos de los Linfocitos T , Reordenamiento Génico de la Cadena gamma de los Receptores de Antígenos de los Linfocitos T , Humanos , Huésped Inmunocomprometido , Inmunofenotipificación , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/inmunología , Linfoma de Células T/genética , Linfoma de Células T/inmunología , Malaria/inmunología , Masculino , Persona de Mediana Edad , Receptores de Antígenos de Linfocitos T gamma-delta/genética , Neoplasias del Bazo/genética , Neoplasias del Bazo/inmunologíaRESUMEN
The high frequency of T cell receptor gamma (TCRG) gene rearrangements in both B-lineage and T cell acute lymphoblastic leukemia (ALL), its easy detection and the lower incidence of oligoclonality make this gene one of the main target for the detection of minimal residual disease by PCR in childhood ALL. We analyzed the frequency and type of TCRG rearrangements in DNA samples obtained from the bone marrow of 102 Brazilian children at diagnosis using PCR and automatic sequencing. TCRG rearrangements were found in 69% of patients with B-lineage ALL and in 94% of patients with T cell ALL. In contrast to other studies, rearrangements involving the Vgamma9 segment reported to be uncommon were the most frequent both in B-lineage and T cell ALL and involved 49/109 (45%) of the rearranged alleles. This fact should be considered when standardizing consensus primers for the study of minimal residual disease in different populations.
Asunto(s)
Reordenamiento Génico de la Cadena gamma de los Receptores de Antígenos de los Linfocitos T , Leucemia-Linfoma Linfoblástico de Células Precursoras/patología , Adolescente , Brasil , Niño , Preescolar , Células Clonales/química , Células Clonales/patología , Secuencia de Consenso , Cartilla de ADN , Femenino , Humanos , Lactante , Leucemia de Células B/genética , Leucemia de Células B/patología , Leucemia de Células T/genética , Leucemia de Células T/patología , Masculino , Neoplasia Residual/diagnóstico , Reacción en Cadena de la Polimerasa/métodos , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Linfocitos T/química , Linfocitos T/patologíaRESUMEN
The leptomeningeal involvement of central nervous system is defined in the most centers by the presence of blast cells in the CSF or the presence of cranial-nerve palsies. Sometimes, cytology does not allow clear distinction between lymphoblasts and normal cells, and auxiliary methods to the precise identification of leukemic cells in cerebrospinal fluid is necessary. We analyzed CSF from 11 consecutive patients, in whom a differential diagnosis of leptomeningeal involvement was made, including 4 patients at diagnosis and 7 patients during the treatment by cytomorphological analysis and PCR and automatic sequencing. Six patients were considered with leptomeningeal involvement by conventional analysis: unequivocal cytomorphological involvement was considered in 5 patients, and in one it was assumed to be due to cranial-nerve palsy, with no blast cells detected in cerebrospinal fluid. In 2 it was considered suspicious and in 3 negative. PCR and sequencing analysis showed involvement in 6 patients; 5 of the 6 patients were considered to have leptomeningeal involvement based on clinical and cytomorphological criteria, and, in one of the patients, it was suspicious. Our data suggest that the use of PCR and sequencing can be useful in confirming CNS leukemia and eliminating other conditions when used together with the cytomorphological analysis.
Asunto(s)
Líquido Cefalorraquídeo/citología , Citodiagnóstico/métodos , Neoplasias Meníngeas/líquido cefalorraquídeo , Meninges/patología , Reacción en Cadena de la Polimerasa/métodos , Leucemia-Linfoma Linfoblástico de Células Precursoras/líquido cefalorraquídeo , Células de la Médula Ósea/química , Células de la Médula Ósea/patología , Niño , Células Clonales/patología , ADN de Neoplasias/líquido cefalorraquídeo , Reordenamiento Génico de la Cadena delta de los Receptores de Antígenos de los Linfocitos T/genética , Reordenamiento Génico de la Cadena gamma de los Receptores de Antígenos de los Linfocitos T/genética , Genes Codificadores de la Cadena delta de los Receptores de Linfocito T/genética , Genes Codificadores de la Cadena gamma de los Receptores de Linfocito T/genética , Humanos , Cadenas Pesadas de Inmunoglobulina/genética , Neoplasias Meníngeas/patología , Leucemia-Linfoma Linfoblástico de Células Precursoras/patología , Reproducibilidad de los ResultadosRESUMEN
We herein present a technical strategy to optimize DNA isolation from paraffin-embedded tissue (PET). This includes the choice of adequate buffers for proteinase K digestion and multiplex PCR amplifications for assessing the appropriateness of DNA extracts for subsequent PCR assays for detecting clonality. We found that the association of proteinase K digestion in nonionic buffer and subsequent extract dilutions accounted for 79% of successful amplifications. A final efficiency of 88% was achieved by additional organic extractions and/or re-extractions. Comparisons were carried out with control DNA extracts from fresh samples to assess the efficiency of each clonality assay. Immunoglobulin CDRIII rearranged region amplification was more efficient for pregerminal center B-cell lymphomas in contrast to CDRII rearrangement detection, which was more effective for germinal and postgerminal lymphomas. T-cell clonality detection by TCRgamma PCR was less efficient in PET samples than in fresh tissues showing that DNA integrity is more critical for TCR than for IGH amplification. Two inconclusive cases without phenotypic markers and two other atypical lymphoproliferations masked by reactive T cells were diagnosed as plasmablastic lymphomas and as monoclonal B-proliferations, respectively, due to IGH rearrangements.
Asunto(s)
ADN de Neoplasias/aislamiento & purificación , Linfoma de Células B/genética , Técnicas de Diagnóstico Molecular , Adhesión en Parafina , Reacción en Cadena de la Polimerasa/métodos , Células Clonales/patología , Cartilla de ADN/química , Endopeptidasa K/metabolismo , Reordenamiento Génico de Cadena Pesada de Linfocito B , Reordenamiento Génico de la Cadena gamma de los Receptores de Antígenos de los Linfocitos T , Humanos , Linfoma de Células B/patologíaRESUMEN
BACKGROUND: The initial response to induction therapy is currently considered one of the most important prognostic factors in acute lymphoblastic leukemias (ALL). A series of methods for the detection of submicroscopic levels of residual disease in patients with ALL mainly based on PCR and immunophenotyping has been developed, demonstrating that the presence of high levels of residual disease at the end of induction therapy is an important, independent prognostic factor. We determined the usefulness of PCR detection of minimal residual disease using consensus primers as a non-remission criterion. PROCEDURE: Bone marrow samples obtained from 49 children with ALL were analyzed at diagnosis and at the end of induction therapy for the detection of clonal IgH, TCRdelta, and TCRgamma rearrangements by PCR. The results were compared with those obtained by standard morphologic analysis and risk group classification. RESULTS: Patients who had clonality detected at the end of induction showed a significantly higher recurrence rate and lower event-free survival than those without detected clonality (24.9% vs. 89.7%) (P < 0.0001). Multivariate analysis revealed that detection of clonality at the end of induction was the most important, independent prognostic factor when associated with age, number of white blood cells, and immunophenotyping. CONCLUSIONS: PCR detection of clonality using consensus primers is a relatively simple technique that is able to identify patients with a high chance of recurrence, and shows a higher sensitivity and a better prognostic value than standard morphologic analysis and risk group classification, defining a new remission criterion. However, further multicentric prospective studies using this technique employing a larger number of cases are necessary to confirm these findings.
Asunto(s)
ADN de Neoplasias/análisis , Reordenamiento Génico de la Cadena delta de los Receptores de Antígenos de los Linfocitos T/genética , Reordenamiento Génico de la Cadena gamma de los Receptores de Antígenos de los Linfocitos T/genética , Reacción en Cadena de la Polimerasa/normas , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Adolescente , Médula Ósea/patología , Niño , Preescolar , Células Clonales/patología , Cartilla de ADN , Supervivencia sin Enfermedad , Femenino , Genes Codificadores de la Cadena delta de los Receptores de Linfocito T/genética , Genes Codificadores de la Cadena gamma de los Receptores de Linfocito T/genética , Humanos , Cadenas Pesadas de Inmunoglobulina/genética , Inmunofenotipificación , Lactante , Masculino , Neoplasia Residual/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/inmunología , Leucemia-Linfoma Linfoblástico de Células Precursoras/mortalidad , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Valor Predictivo de las Pruebas , Modelos de Riesgos Proporcionales , Inducción de Remisión , Sensibilidad y EspecificidadRESUMEN
BACKGROUND: The purpose of this investigation was to analyze the incidence of clonal evolution in children in Brazil children with acute lymphoblastic leukemia and its interference with the detection of minimal residual disease by polymerase chain reaction using clone-specific primers. PATIENTS AND METHODS: The authors analyzed DNA samples from 12 children with acute lymphoblastic leukemia at diagnosis and after relapse using polymerase chain reaction and automatic sequencing to determine the presence of T-cell receptor gamma (TCRgamma) gene rearrangements. A clone-specific primer was synthesized based on the sequence obtained at diagnosis for each patient and at relapse for those with clonal evolution for the study of minimal residual disease. RESULTS: A change of the original clone was detected in 3 of 12 patients (25%), involving the same rearrangement detected at diagnosis, suggesting the development of subclones. Minimal residual disease was detected at the end of treatment or before the relapse in all patients who had maintained the same rearrangements detected at diagnosis. Minimal residual disease was investigated at the end of treatment in two of the three patients with clonal evolution and was not detected with the use of clone-specific primers. CONCLUSIONS: These data suggest that clonal evolution for TCRgamma gene rearrangements was not a rare event among children in Brazil and, when present, interfered with the detection of minimal residual disease.
Asunto(s)
ADN de Neoplasias/análisis , Reordenamiento Génico de la Cadena gamma de los Receptores de Antígenos de los Linfocitos T/genética , Leucemia Linfoide/diagnóstico , Leucemia Linfoide/genética , Enfermedad Aguda , Brasil , Niño , Preescolar , Cartilla de ADN/química , Femenino , Genes Codificadores de la Cadena gamma de los Receptores de Linfocito T/genética , Humanos , Inmunofenotipificación , Lactante , Neoplasia Residual , Reacción en Cadena de la PolimerasaRESUMEN
The minimal residual disease (MRD) detection by the polymerase chain reaction (PCR) in children with acute lymphoblastic leukemia has been pointed to be an adverse prognostic factor. Detection methods based on this technique using clone-specific primers are cumbersome and time consuming. The detection of monoclonal gene rearrangements of gamma T-cell receptors (TCRgamma) is a simpler although less sensitive method. In the present study, we analyzed the presence of MRD during four different phases of treatment (week 4; 3-6, 12-24 months, and end of treatment) in 34 Brazilian children with lymphoid leukemia by three detection methods based on the PCR technique: (1) using consensus primers for the detection of a clonal population for TCRgamma; (2) clone-specific primers for the junctional region of TCRgamma; and (3) a semi-nested reaction with an initial cycle with consensus primers followed by a second cycle with clone-specific primers. MRD presence was associated with a shorter event-free survival and was the major independent prognostic factor in most of the phases analyzed. The use of consensus primers for the detection of TCRgamma clonality, although less sensitive, proved to be a simpler, faster and less costly method whose positivity was associated with more than 90% relapse rates during all phases analyzed.
Asunto(s)
Reacción en Cadena de la Polimerasa/métodos , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico , Adolescente , Brasil , Niño , Preescolar , Femenino , Reordenamiento Génico de la Cadena gamma de los Receptores de Antígenos de los Linfocitos T , Humanos , Lactante , Masculino , Neoplasia ResidualRESUMEN
The frequency of the hybrid Vgamma/Jbeta trans-rearrangement in peripheral blood lymphocytes (PBLs) was analysed in a transversal study of paediatric patients (n = 210) with acute lymphoblastic leukaemia (ALL) and solid tumours (ST). Different amounts of DNA were used as the template for a nested polymerase chain reaction to evaluate the frequency of hybrid Vgamma/Jbeta genes, using silver-stained gels. The frequency of the rearrangement was evaluated in groups before, during and after therapy. A greatly increased frequency of Vgamma/Jbeta trans-rearrangement was found in PBLs of both groups of patients during exposure to chemotherapeutic agents compared with patients before chemotherapy. In patients who had finished treatment, the frequency of the rearrangement fell promptly to the baseline levels in ST but showed a slow decrease in ALL in those in whom increased levels could be found until 4 years after the end of treatment. We hypothesize that the chemotherapeutic agents are able to induce the Vgamma/Jbeta trans-rearrangement, but this is transient in most cases. The exact relationship between the persistence of the rearrangement and the occurrence of secondary leukaemia remains to be determined.
Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Reordenamiento Génico de la Cadena beta de los Receptores de Antígenos de los Linfocitos T , Reordenamiento Génico de la Cadena gamma de los Receptores de Antígenos de los Linfocitos T , Neoplasias/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Antraciclinas/administración & dosificación , Antraciclinas/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Estudios de Casos y Controles , Niño , Preescolar , Protocolos Clínicos , Electroforesis en Gel de Poliacrilamida , Estudios de Seguimiento , Marcadores Genéticos , Enfermedad de Hodgkin/tratamiento farmacológico , Enfermedad de Hodgkin/genética , Humanos , Neoplasias/tratamiento farmacológico , Osteosarcoma/tratamiento farmacológico , Osteosarcoma/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/inducido químicamente , Rabdomiosarcoma/tratamiento farmacológico , Rabdomiosarcoma/genética , Sarcoma de Ewing/tratamiento farmacológico , Sarcoma de Ewing/genética , Factores de TiempoRESUMEN
A 17-year-old girl presented with a lymphoproliferative disease involving the bone marrow, peripheral blood, and liver associated with reactive hyperplasia of the spleen. Neoplastic cells were atypical medium-sized lymphoblasts with convoluted nuclei and nucleoli without features of large granular lymphocytes (LGL). The phenotype was CD3+ CD4- CD8-, TCR alpha/beta-, TCR gamma/delta+, delta TCS1-, and CD16+, and these cells exhibited spontaneous natural killer (NK) activity. DNA analysis showed rearrangement of the TCR gamma gene but not of TCR beta or of Ig mu genes. This unusual lymphoproliferative disease may represent the neoplastic expansion of a minor subset of normal T gamma/delta cells with NK activity.