CMV infection in the donor and increased kidney graft loss: impact of full HLA-I mismatch and posttransplantation CD8(+) cell reduction.

Despite a large body of literature, the impact of chronic cytomegalovirus (CMV) infection in donor on long-term graft survival remains unclear, and factors modulating theeffectofCMVinfectionongraftsurvival arepresently unknown. In this retrospective study of 1279 kidney transplant patients, we analyzed long-term graft survival and evolution of CD8+ cell population in donors and recipients by CMV serology and antigenemia status. A positiveCMVserology in thedonorwas an independent risk factor for graft loss, especiallyamong CMV-positive recipients (R+). Antigenemia was not a risk factor for graft loss and kidneys from CMV-positive donors remained associated with poor graft survival among antigenemia-free recipients. Detrimental impact of donor's CMV seropositivity on graft survival was restricted to patientswith fullHLA-I mismatch, suggesting a role of CD8+ cells. InR+ patients with positiveCMV antigenemiaduringthefirstyear, CD8+cellcountdidnot increase at 2 yearsposttransplantation, incontrast toR(-) recipients. In addition, markedCD8+-cell decreasewas a risk factor of graft failure in these patients. This study identifiesHLA-I fullmismatchandadecreaseofCD8+cell count at 2 years as important determinants of CMVassociated graft loss.