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

ABSTRACT

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