Human leukocyte antigenic specificity HL-A3: frequency of occurrence.

Reactivity of antiserum against HL-A3, a human leukocyte and tissue antigenic specificity, depends upon a property of the lymphocyte as well as on the potency of the serum. Many reactions of HL-A3 antiserums can only be recognized through absorption or by a two-stage test not in general use. Interpretations of donor-recipient compatibility and of the constitution of HL-A alleles affected by these findings.