IgM immune complexes, lymphocytotoxins, and rheumatoid factors in renal transplant recipients with CMV disease.

In studying 127 consecutive adult recipients of cadaver renal transplants, we found that the 23 patients who developed CMV disease produced IgM immune complexes as measured by a polyethyleneglycol precipitation (PEG) assay which coincided with symptoms of their illness. In addition to anti-CMV antibodies, PEG precipitated apparently non-specific antibodies such as lymphocytotoxins and rheumatoid factor (RF). The lymphocytotoxins were IgM antibodies that were not directed against HLA antigens and lysed granulocytes as well as lymphocytes but not platelets at 22 degrees C. Lymphocytotoxin production was correlated with HLA-DR 3 and 7 and with graft dysfunction during the CMV disease. The RF also were predominantly IgM antibodies that were detectable for only 3-8 weeks. The production of RF coincided with the initial rise in IgG anti-CMV antibody activity and some reacted with the Fab fragments of IgG raising the possibility that they could modulate the cellular or humoral immune response to CMV. Patients with RF tended to have severe CMV infections with pneumonia and graft dysfunction.