Renal graft dysfunction during infection with cytomegalovirus: association with IgM lymphocytotoxins and HLA-DR3 and DR7.

Of 121 consecutive adult recipients of cadaver renal transplants who were treated with low dose steroids and azathioprine, 23 developed active cytomegalovirus infections. These 23 patients were divided into three groups on the basis of their symptoms related to the infection: five patients had no renal, respiratory, or haematological abnormalities; seven had renal dysfunction; and nine had renal dysfunction plus respiratory or haematological abnormalities. Two patients were regarded as a separate group because their infections occurred two to four weeks after graft nephrectomy. All but three of the patients produced IgM or IgG lymphocytotoxins during their infections. In the patients with mild infections and in control patients without infections, however, these lymphocytotoxins were predominantly IgG antibodies that were not precipitated by 3.5% macrogol (polyethylene glycol). In contrast, 12 of the 16 patients with renal dysfunction during their infections had broadly reactive IgM lymphocytotoxins. These IgM lymphocytotoxins lysed T as well as B lymphocytes at 22 degrees C and were precipitated by 3.5% macrogol, suggesting that they were circulating as immune complexes. Rheumatoid factors were found in sera from nine patients with cytomegalovirus infections, seven of whom developed leukopenia or pneumonia, or both, in addition to renal dysfunction. Some of these immune responses associated with cytomegalovirus infection in transplant recipients may be genetically controlled since 10 of 11 patients positive for HLA-DR3 or DR7 produced IgM lymphocytotoxins.