Capping of leukemic cells with monoclonal anti-HLA-A,B,C related to prognosis in childhood acute lymphoblastic leukemia.

Capping of leukemic cells with a monoclonal antibody against HLA A,B,C determinants was studied in 53 cases of childhood acute lymphoblastic leukemia (ALL). Determination of the percentages of capped cells after different times of incubation with anti-HLA A,B,C show that T ALL and common ALL do have quite different kinetics of HLA capping. In T ALL all cases reach levels of percentage of capped cells above 30%, in common ALL only 11 of 31 cases cap well. Dilution of the antiserum in 6 common ALL cases results in an increase of capped cells, but the original kinetics of the common ALL capping remain. ALL cases with capping curves above 30% have a worse prognosis (shorter continuous complete remission) than cases with capping curves below 30% in the total group as well as in the non-high-risk group.