Síndromes linfoproliferativos crónicos en Chile: estudio prospectivo de 132 casos / Chronic lymphoproliferative disorders in Chile: a prospective study in 132 patients

Background: Chronic lymphoproliferative disorders include a variety of diseases which are often a diagnostic problem for clinical hematologists. Aim: To study prospectively the distribution and incidence of chronic lymphoproliferative disorders in Chile and compare them with those of other Western, Latin American and Oriental countries. Patients and methods : A group of 132 patients were studied in a 36 months period (1999-2001), with a panel of monoclonal antibodies. A score for chronic lymphocytic leukemia was employed to differentiate it from other B-cell disorders. Results : The median age was 63 years old (range 32-94). Most patients had B-cell tumors (109) and the rest (23), T-cell tumors (82 percent vs 18 percent). Forty five percent of patients with B-cell tumors had a chronic lymphocytic leukemia (CLL), while the others were disseminated lymphomas. The incidence of T-cell tumors was slightly higher than that of other Western countries. Noteworthy is that the most common of these disorders was adult T cell leukemia/lymphoma (ATLL), in concordance with the high HTLV-1 seroprevalence in Chile. Conclusions : A morphologic, immunophenotypic and pathological study in a large number of patients with chronic lymphoproliferative disorders in Chile, shows a relatively low incidence of CLL when compared to other chronic B-cell tumors and a high representation of ATLL associated to HTLV-1 infection, compared with other Western countries. The lower incidence of CLL in our study might be due to patient's selection and/or underdiagnosis of this disease as a substantial proportion of CLL are asymptomatic

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