The problem of cytomegalovirus infection in renal allograft recipients.

A prospective study of the effects of cytomegalovirus (CMV) infection on 145 recipients of 155 renal allografts is reported. Immunosuppression was either with azathioprine and low-dose prednisolone (103 transplants) or with Cyclosporin A (52 transplants). Sixty-one cases of CMV infection were diagnosed; of those 21 were primary (i.e. in CMV sero-negative recipients) and 40 were secondary (i.e. in previously sero-positive recipients). The infection rate in patients treated with azathioprine and low-dose prednisolone did not differ from the rate in those treated with Cyclosporin A. Eighteen of the 21 primary CMV infections were clinically overt; several of these patients became seriously ill, and one of them died. Only four of the 40 secondary infections were overt, and these were all mild. Graft and patient survival were not adversely affected by CMV infection. Indeed the group with secondary CMV had significantly better survival rates than the uninfected sero-positive or sero-negative patient groups. Recommendations to minimise the effects of primary CMV infections are given.