Adult T-cell leukemia/lymphoma.

Adult T-cell leukemia/lymphoma (ATL) is a malignancy of mature CD4+ T-cells caused by human T-cell lymphotropic virus type 1 (HTLV-1). Twenty million people are believed to be infected throughout the world, mostly in Japan, Africa, the Caribbean, and South America, particularly in Brazil and Peru. ATL affects about 5% of infected individuals and is classified in the following clinical forms: acute, lymphoma, primary cutaneous tumoral, chronic (favorable and unfavorable), and smoldering (leukemic and non-leukemic). Although it is considered an aggressive disease, there are cases with a long progression. We emphasize the importance of clinical classification as an indispensable element for evaluating prognosis and appropriate therapeutic approach. Since several cases have been published in Brazil and this disease is still poorly known, we decided to make a review paper for dissemination of clinical, hematological and pathological aspects, diagnosis, and therapy. The best way to reduce the occurrence of ATL would be halting the transmission of the virus through breastfeeding.

Adult T-cell leukemia/lymphoma / Leucemia/linfoma de células T do adulto

Summary Adult T-cell leukemia/lymphoma (ATL) is a malignancy of mature CD4+ T-cells caused by human T-cell lymphotropic virus type 1 (HTLV-1). Twenty million people are believed to be infected throughout the world, mostly in Japan, Africa, the Caribbean, and South America, particularly in Brazil and Peru. ATL affects about 5% of infected individuals and is classified in the following clinical forms: acute, lymphoma, primary cutaneous tumoral, chronic (favorable and unfavorable), and smoldering (leukemic and non-leukemic). Although it is considered an aggressive disease, there are cases with a long progression. We emphasize the importance of clinical classification as an indispensable element for evaluating prognosis and appropriate therapeutic approach. Since several cases have been published in Brazil and this disease is still poorly known, we decided to make a review paper for dissemination of clinical, hematological and pathological aspects, diagnosis, and therapy. The best way to reduce the occurrence of ATL would be halting the transmission of the virus through breastfeeding.

Resumo A leucemia/linfoma de células T do adulto (LLcTA) é uma neoplasia de células T maduras CD4+ causada pelo vírus linfotrópico para células T humanas tipo 1 (HTLV-1). Acredita-se que existem cerca de 20 milhões de pessoas infectadas em todo o mundo, principalmente no Japão, na África, no Caribe e na América do Sul, particularmen te no Brasil e no Peru. A LLcTA acomete cerca de 5% dos indivíduos infectados e classifica-se nas seguintes formas clínicas: aguda, linfomatosa, tumoral primária de pele, crônica (favorável e desfavorável) e indolente (leucêmica e não leucêmica). Embora seja considerada uma doença agressiva, há casos com longa evolução. Salientamos a importância da classificação clínica como elemento im prescindível para avaliação do prognóstico e conduta terapêutica adequada. Como já foram publicados vários casos no Brasil e essa doença ainda é pouco conhecida, decidimos fazer um trabalho de revisão para divulgar os seus aspectos clínicos, hematológicos, anatomopatológi cos, diagnósticos e terapêuticos. O melhor meio de redu zir a ocorrência de LLcTA seria sustando a transmissão vertical do vírus pela amamentação.

Adult T-cell leukemia/lymphoma in Bahia, Brazil: analysis of prognostic factors in a group of 70 patients.

The purpose of this study was to evaluate whether subdivision of adult T-cell leukemia/lymphoma (ATL) on the basis of clinical types, skin involvement, histologic features, cell size, and proliferative index (PI) was clinically relevant. Skin lesions were present in 47 cases (67%). Five cases were classified as primary cutaneous tumoral (PCT) type not included in the Shimoyama classification and characterized by skin tumors and absence of systemic involvement, lymphocytosis, and hypercalcemia. Mortality was high (61/70 [87%]). The overall median survival time (MST) was 12 months. The following variables were adversely related to survival: acute, lymphoma, and PCT types; absence of skin lesions; large cells; and PI more than 18%. The longer MST observed in cases with skin lesions was probably due to prolonged survival of the smoldering type (58 months). The MST of the PCT type (21 months) was shorter than that of the smoldering type, confirming the importance of clearly defining these 2 types of ATL.

Flow cytometric analysis of cell-surface and intracellular antigens in the diagnosis of acute leukemia.

To evaluate the usefulness of flow cytometric detection of intracellular antigens (Ags) in establishing proper lineage affiliation and its contribution to the diagnosis of acute leukemia, we studied 100 consecutive patients in whom acute leukemia was diagnosed between January 1997 and July 1998. Immunological classification was assessed using a three-line panel of monoclonal antibodies for phenotypic characterization of leukemic blast cells as proposed at the First Latin American Consensus Conference for Flow Cytometric Immunophenotyping of Leukemia. We found 74 cases of B-cell lineage acute lymphoblastic leukemia (ALL), seven cases of T-cell ALL, and 19 cases of acute myeloid leukemia (AML). In this study cytoplasmic (cy) CD79a, cyCD22, cyCD3, and cyMPO were highly sensitive, specific B, T, and myeloid markers that were expressed in virtually all cases of B and T cell ALL and in all subtypes of AML. Applied in combination with immunophenotyping this knowledge led to improvement in diagnostic precision and refinement of immunological classification, ensuring the selection of the most appropriate therapy for the patients studied. In conclusion, intracellular Ags detection was of utmost importance in establishing correct lineage affiliation in cases lacking expression of B, T, or myeloid surface Ags or disclosing equivocal or ambiguous immunophenotypic features and in identifying biphenotypic acute leukemia. In combination with FAB morphology and immunophenotyping, we were able to reliably classify all patients with acute leukemia in this study.