Cytomegalovirus Infection after Renal Transplantation: Occurrence, Clinical Features, and the Cutoff for Antigenemia in a University Hospital in Brazil

Background: Cytomegalovirus (CMV) is the main infectious agent causative of morbidity and mortality in transplant recipients. This study aimed to describe the occurrence and clinical features of CMV infection, and the optimum antigenemia assay cutoff associated with symptomatic infection.

Materials and methods: This was a cohort study that investigated 87 patients undergoing renal transplantation. The patients were monitored with the CMV antigenemia assay performed weekly for the first 3 months post-transplantation and subsequently, when CMV infection was suspected clinically.

Results: CMV infection was observed in 63.2% (55/87) of the recipients during the follow-up. Of the 65 episodes observed, 75% (49/65) occurred until 100 days after transplantation (D+100) and 25% (16/65) after D+100 with a median of 60 days. CMV infection was associated with age of the transplant recipients (P = 0.001) and use of deceased donor organ (P = 0.009). There were asymptomatic (34%) and symptomatic (66%) episodes of CMV infection, in which diarrhea was the most common symptom (22.6%), followed by elevated creatinine levels (14.5%), fever (12.9%) and leukopenia (10.5%). The optimum cutoff point associated with symptomatic infection was 5 positive cells/200,000 leukocytes (area under the curve = 0.87, positive predictive value = 88% and negative predictive value= 71%).

Conclusions: The high occurrence and the risk factors for CMV infection such as the age of recipients, the number of positive cells in the antigenemia assay, and use of a deceased donor organ should be considered for appropriate monitoring and management of kidney recipients during the post-transplant period.