ABSTRACT
Background: Acute leukemia (AL) in infants generally shows distinctive biologic features and has a poor prognosis. Aim: To study the frequency of the cytogenetic alteration of11q23 chromosome or the recombination of MLL gene in infants less than 18 months old, with acute leukemia. Patients and methods: We analyzed 37 cases of AL in infants less than 18 months of age diagnosed in Chile from 1989 to 1999. The clinical features and cytogenetic/molecular defects of 11q23MLL gene rearrangement and their influence in prognosis were determined. Results: There were 18 cases of acute Lymphoblastic leukemia (ALL) characterized by female sex (67 per cent) high presenting leukocyte count (median 99 x109/L), blast cells with a CD10 negative phenotype (50 per cent) and 11q23/MLL rearrangement (39 per cent). Molecular abnormalities of 11q23 were significantly associated with adverse prognosis, with an event free survival (EFS) of only 14 ñ 12 per cent. Interestingly, infants with germ line 11q23 had a very good outcome with an EFS of 73 ñ 11 per cent (p<0.025). There were 19 cases of acute myeloblastic leukemia (AML) characterized by male sex (63 per cent) high leukocyte count (median 93 x 109/L), FAB-MS morphology (53 per cent) and 11q23/MLL rearrangement (53 per cent). EFS was very poor, 20 ñ 9 per cent and 33ñ4 per cent for rearranged and germinal group respectively (p=NS), due to a high mortality rate during the first month of diagnosis. Conclusions: These findings demonstrate that Chilean ALL infants with 11q23 abnormalities have a very poor prognosis. However those with germinal state can enjoy a prolonged disease free survival with the current treatment protocols
Subject(s)
Humans , Male , Female , Infant , Chromosomes, Human, Pair 11/genetics , Leukemia, Myeloid, Acute/genetics , Chromosome Aberrations/genetics , Precursor Cell Lymphoblastic Leukemia-Lymphoma/genetics , Leukemia, Myeloid, Acute/diagnosis , Cytogenetic Analysis , Precursor Cell Lymphoblastic Leukemia-Lymphoma/diagnosis , Genetic Markers/genetics , Prognosis , Recombination, Genetic/geneticsABSTRACT
Background: Adult T cell leukemia lymphoma is a lymphoproliferative syndrome etiologically associated to human T cell lymphotropic virus type I. Aim: To describe the clinical and laboratory features of 26 caucasian chilean patients, with HTLV-I positive adult T-cell leukemia lymphoma (ATLL). Material and methods: Diagnostic criteria included clinical features, cell morphology, immunophenotype, HTLV-I serology and/or DNA analysis by southern blot or PCR. Results: According to the clinical presentation, 12 cases had the acute ATLL form, 6 had a lymphoma, 4 the chronic form and 4 had smoldering ATLL. The median presentation age was 50 years, younger than the Japanese patients, but significantly older than patients from other south american countries (eg Brasil, Jamaica, Colombia). The main clinical features: lymphadenopathy, skin lesions and hepatosplenomegaly, were similar in frequency to those of patients from other countries, except for the high incidence of associated neurological disease. Tropical spastic paraparesis (TSP) in our series of ATLL, was seen in one third of the patients (8/26). A T-cell immunophenotype was shown in all 26 cases and HTLV-I serology was positive in 25/26 patients. Molecular analysis on the seronegative patient showed clonal integration of proviral HTLV-I DNA into the lymphocytes DNA, and thus he may have been a poor responder to the retroviral infection. Proviral DNA integration was also demonstrated in 15/16 patients being clonal in 10, polyclonal in 3 (all smoldering cases) and oligoclonal in one. Conclusions: ATLL in Chile has similar clinical and laboratory features than the disease in other parts of the world, except for a younger age than japanese patients but older than those from other latin american countries and a high incidence of patients with associated TSP. Detailed morphological and immunophenotypic analysis of the abnormal circulating lymphocytes, together with the documentation of HTLV-I by serology and/or DNA analysis are key tests for the identification of this disease