Cytomegalovirus seromismatching increases the risk of acute renal allograft rejection

Background. There is an association between cytomegalovirus (CMV) infection or disease and acute allograft rejection in the setting of renal transplantation. There is, however, debate regarding the nature of this association, with evidence supporting both a "forward" relationship (CMV infection or disease precedes acute rejection) and a "backward" relationship- (CMV infection or disease follows acute rejection). The objective of this study was to determine whether. CMV matching had an independent effect on the risk of acute renal allograft rejection, which would support the view that CMV infection or disease is a risk factor for acute rejection. Methods. Retrospective single center study (using a prospectively maintained database) of 333, first cadaveric transplant recipients from January 1st 1991 to December 31st 1997. Primary end-point was incidence of acute rejection, diagnosed clinically or by renal biopsy, for different groups formed on the basis of CMV seromatching. Results. One hundred and ninety-four patients (58.3%) had at least one acute rejection episode. CMV seromismatched patients (donor +/recipient-) had a significantly higher rate of acute rejection than nonseromismatched patients (72.6% vs. 54.2%, P=0.005). Using multiple logistic regression, CMV seromis-match, delayed graft function, and biological induction were identified as independent predictors of acute rejection. The adjusted odds ratios for these were 2.28,.1.65, and 0.52, respectively. Conclusions. Patients who are CMV seromismatched are at higher risk of acute renal allograft rejection. This finding suggests that CMV infection or disease is a risk factor for acute rejection.