Clinical significance of childhood acute myeloid leukemias expressing lymphoid-associated antigens.

The clinical significance of the expression of lymphoid-associated antigens in leukemic cells was studied in 66 children with newly diagnosed acute myeloid leukemia (AML). Among 66 AML cases, 17% were CD7-positive, 15% were CD19-positive, 8% were CD2-positive, and 5% were CD10-positive. In 23 (35%) of the 66 AML cases, at least one lymphoid-associated antigen was expressed in the leukemic cells. When the clinical features and laboratory findings were compared at diagnosis between the 23 Ly+ and the 43 Ly- AML cases, no statistically significant difference was found. The expression of CD34 was significantly more frequent in Ly+ AML cases (91%) than in Ly- AML cases (31%). Chromosomal analysis revealed t(8;21) in 6 of the 21 Ly+ AML cases examined. No other specific chromosome aberration was noted. The 3-year event-free survival rates of Ly+ AML cases and Ly- AML cases were 34% +/- 12% and 26% +/- 8%, respectively. There was no statistically significant difference between the two groups. Further studies are required to determine the prognostic significance of lymphoid-associated antigen expression.