HL‐A Antigens and Acute Lymphocytic Leukemia: The Nature of the HL‐A2 Association

Abstract

Beginning in 1969, HL–A antigens were determined for 85 Caucasian patients with acute lymphocytic leukemia (ALL). HL–A2 was the only antigen significantly different from a normal racial control group. It was present in 65 % of patients as compared to 44% of the controls ( P .005). Fifty‐three of the 85 patients were diagnosed between 1969 and 1971 and were typed soon after admission. Their HL–A antigen frequencies were normal. The other 32 patients had been diagnosed previously (1962–1968), and thus were survivors at the time of typing. Their HL–A2 frequency was 84%. The frequency of HL–A2 in patients surviving 1500 days or more was 83%. The combined frequency of HL–A2, the known related specificity W28 and the possibly related HL–A9 in these long‐term survivors was 94%. These data suggest that HL–A2 (and possibly HL–A9 and W28) is not associated with disease susceptibility, as was previously thought, but rather confers a form of resistance to ALL. This hypothesis can be tested best by a large scale prospective study.