Time trend in frequency of occurrence of major immunophenotypes in paediatric acute lymphoblastic leukemia cases as experienced by Cancer Institute, Chennai, south India during the period 1989-2009.

Background: Pediatric acute lymphoblastic leukemia (ALL) is a biologically heterogeneous disease and socioeconomic and environmental factors are considered to be an important determinant of its immunophenotype. The aim of this analysis is to study the time trend in the immunophenotype of pediatric acute lymphoblastic leukemia (ALL) cases in our geographic setting. Materials and Methods: A total of 639 new pediatric ALL cases immunophenotyped during 1989-2009 forms the basis of this analysis. Representative bone marrow or peripheral blood of these patients was immunophenotyped flowcytometrically using an extensive panel of monoclonal antibodies. Results: During early phase of our study we noticed a relative excess of T-ALL and a paucity of common acute lymphoblastic leukemia (C-ALL) in contrast to western data. Over a period of 20 years we witnessed a gradual reduction in pediatric T-ALL cases and a proportionate increase in C-ALL cases. Conclusion: We find that this change of pattern is synchronizing with the socioeconomic and industrial development prevailing in our geographic setting and suggest a possible link between the predominant immunophenotype of pediatric ALL cases and the environmental and socioeconomic factors prevailing in that locality.

Método de reação em cadeia por polimerase para a pesquisa de retrovírus em casos de linfomas não-Hodgkin de células T periféricas e paraparesias crurais espásticas / PCR methods for retrovirus search in cases of non-Hodgkin lynphoma of peripheral T-cells and crural spastic paraparesis

Partindo de dois oligonucleotídeos degenerados derivados de uma fração conservada da região pol de retrovírus conhecidos, foi pesquisada a presença de agente viral exógeno ou de uma seqüência endógena similar as retrovirais (ERV). A partir da amplificação do DNA pela técnica de PCR, foram testadas células mononucleares periféricas de 33 portadores de paraparesia crural espática de evolução crônica sem agente etiológico conhecido, produzindo um fragmento de aproximadamente 500 bp em 8 destas amostras...

CD44 Expression in T-cell lymphoblastic leukemia

1. CD44 is an adhesion molecule expressed by B and T lymphocytes that mediates cell attachment to extracellular matrix components and specific cell surface ligands. In normal process of T-cell development, CD44 can be implicated in homing of bone marrow-derived T-cell precursors into the thymus. In hematopoietic malignancies, CD44 and other adhesion molecules can mediate the behavior of neoplastic cells such as metastatic migration. In the leukemic process, CD44 and other adhesion molecules can mediate the behavior of neoplastic cell such as metastic migration. In the leukemic process, CD44 expression is correlated with increased numbers of circulating blasts and it is present at other sites such as the central nervous system. 2. In the present study, CD44 was investigated in lymphoblasts from 30 patients with T-cell lymphoblastic leukemia (T-ALL) and peripheral lymphocytes from 10 healthy individuals. CD44 expression was detected in 23 (77 per cent) of T-ALL cases studied and was correlated with clinical features such as mediatinal mass, adenomegaly, and infiltration of the central nervous system and other ortgans. Interestingly, CD44 expression in patient with tumor infiltration was higher than in patients with no tumor infiltration. 3. These data suggest that CD44 may be regarded as an additional marker for tumor expansion in T-cell leukemias

Infección por HTLV-I, leucemia de células T del adulto y factor con actividad de parathormona

La infección por el virus linfotrópico humano tipo I (HTLV-I) se ha asociado a la paraparesia espástica tropical (PET) y a la leucemia/linfoma de células T del adulto (ATL). Recientemete se demostró que los desordenes del metabolismo del calcio que acompañan la ATL son debidos a la secreción de un factor con actividad de parthormonas producido por los linfocitos infectados por el HTVL-I. Se presenta el caso de una paciente con anticuerpos contra el HTVL-I, anormalidades en el metabolismo del calcio y con parámetros que la clasifican en uno de los subtipos de ATL.