Leucemia linfoma T del adulto en Chile: estudio clínico patológico y molecular de 26 pacientes / Adult T cell leukemia lymphoma in Chile: a clinical-pathological and molecular study of 26 patients

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

Leucemia mieloide aguda MO: características clínicas y de laboratorio / Acute myeloid leukemia MO: clinical and laboratory features

Patients and methods: Eight patients, our of 368, with acute myeloid leukemia that were studied in the Hematology Laboratory of a public hospital in Santiago, were classified as LMA-MO. Results: Blast cell morphology was undifferentiated or of subtype FAB-L2 lymphoblastic leukemia with medium sized blasts, agranular basophilic cytoplasm, reticular nuclear chromatin and a prominent nucleolus. Cytochemical staining was negative for peroxidase and esterases, immunophenotyping showed the expression of one or more myeloid antigens (CD13, CD33) and was negative for lymphoid antigens. Immunocytochemical expression of myeloperoxidase was positive in the three cases where it was performed. Only one patient achieved complete remission and is free of disease after 36 months of follow up. All other patients died without obtaining remission, six shortly after the onser and one 12 months after. Conclusions: The diagnosis of LMA-MO is essential considering its dismal prognosis

Inmunofenotipo: características clínicas y laboratorio de la leucemia linfoblástica aguda en Chile: estudio de 500 niños y 131 adultos / Immunophenotype: clinical and laboratory characteristics of acute lymphoblastic leukemia in Chile: study of 500 children and 131 adults

We describe the clinical features and immunophenotype of 500 children and 131 adults with acute lymphoblastic leukemia (ALL), diagnosed between 1984 and 1993. Cases were classified according to immunophenotype in B-cell ALL accounted for 74 percent of cases and pro-B ALL was more common in children of less than 1 year (14 percent). B ALL was observed in 2 percent of children. Ten percent of children, mostly males, had T-cell ALL. The third part of these children had high leukocyte counts and a mediastinal mass. Children from Mapuche origin, compared with Caucasian had a lower proportion of common ALL (36 and 74 percent respectively) and a higher proportions of T-cell ALL (41 and 10 percent respectively). Among adults common ALL was the most common phenotype (72 percent) followe by T-cell ALL (15 percent), pro-B ALL (11 percent) and B-cell ALL (2 percent). There was a lower incidence of children with common ALL with positive cytoplasmatic immunoglobulin, compared to North American or European studies (2 and 15-33 percent respectively) and a higher proportion of adults with common ALL compared with pro-B cell ALL, in contrast to European studies that show a higher proportion of patients with pro-B cell ALL. No other immunophenotypic, clinical or laboratory differences were observed with ALL. No other immunophenotypic, clinical or laboratory differences were observed with ALL from developed countries. It is concluded that the immunophenotyping of ALL, allows a more precise diagnosis of this disease

Leucemia prolinfocítica, descripción de dos casos / Prolymphocytic leukemia, description of 2 cases

We present the clinical and laboratory features of 2 patients with B prolymphocitic leukemia. Both are females of the fith and seventh decade of life. One had the classical clinical picture of massive splenomegaly and a high white cell count, with characteristic prolymphocytes and the other was asymptomatic, with a low white cell count. The cells were positive to B cell lineage reagents with strong surface immunoglobuline (Ig) and unreactive to T cell antibodies. Analysis of Ig genes at the DNA level demonstrated that both cases had heavy-chain gene rearrangements, confirming the B-cell origin. These are the first patients of prolymphocytic leukemia described in Chile