DONOR-SPECIFIC ANTI-HUMAN LEUKOCYTE ANTIGEN CLASS-I ANTIBODIES AFTER IMPLANTATION OF CARDIAC-VALVE ALLOGRAFTS

The allospecific humoral immune response was examined in 31 patients i n the first year after implantation of cryopreserved human cardiac val ves. We determined the percentage antibodies against human leucocyte a ntigens (HLA) class I in a complement-dependent microlymphocytotoxicit y test against a panel of 50 selected donors carrying most of the defi ned HLA-A and HLA-B specificities (panel-reactive antibodies). In bloo d samples taken immediately before implantation, no antibodies could b e detected. Thereafter, antibodies were present in 23 of 31 (74%) pati ents (median panel-reactive antibodies: 57%, range 9% to 91%). In 21 p atients the HLA-type of the valve donor was available. In four patient s no blood samples taken after 4 weeks were available. In 14 of 17 pat ients (82%) with a follow-up of more than 1 month antibodies were pres ent, and in 12 of these 14 (86%) antibodies were specifically directed against HLA class I of the donor. In conclusion, the formation of don or-specific antibodies is frequently observed after human cardiac valv e replacement. It could be one of the factors leading to valve destruc tion and dysfunction.