Absence of detectable HL-A antigens on cultured fibroblasts in progeria.

HL-A phenotypes were determined by a cytotoxicity assay on circulating lymphocytes of two boys with the premature aging syndrome, progeria. The antigenic phenotypes were not unusual inasmuch as they are frequently seen in the normal population. However, none of these antigens could be detected by the same assay on cultured skin fibroblasts from either individual, even when a significant mitotic potential remained before cessation of growth. Fibroblasts from normal donors were concordant with corresponding lymphocytes for HL-A antigens and maintained these antigens until mitotic division had virtually ceased. Absorption studies on fibroblasts with two HL-A2 antisera revealed that HL-A antigens are either absent or have a drastically reduced expression on progeric fibroblasts. The data are in accord with the concept of an immunological role in the pathogenesis of progeria.