CYTOMEGALOVIRUS-INFECTION AND ALLOSPECIFIC CYTOTOXIC ACTIVITY OF GRAFT-INFILTRATING CELLS AFTER HEART-TRANSPLANTATION

We have investigated whether cytomegalovirus (CMV) infection has an ef fect on donor directed cytotoxicity of graft-infiltrating cells in hum an heart transplants. Our study group consisted of 89 heart transplant recipients. Thirty-eight (43%) showed signs of CMV infection; in 28 o f them, cytolytic activity of biopsy derived cultures could be tested during the infection. Eight patients had a primary and 20 a secondary infection. We found that during CMV infection, both primary and second ary, a significantly higher proportion of the biopsy-derived cultures showed cytotoxicity against donor HLA antigens (chi(2) test; P < 0.01 in comparison with 51 patients without infection). Th is was most evid ent in patients with both infection and acute rejection episodes when compared to patients with only one of these complications. This sugges ts that one process amplifies the other with regard to the up-regulati on of alloreactivity within the transplanted heart. In secondary infec tions, only an increase of donor class I-directed cytotoxicity was fou nd, while in primary infections cytotoxicity against donor class I and II antigens was increased (P < 0.005 vs. secondary infection). (C) 19 94 Wiley-Liss, Inc.