The Incidence of Cytomegalovirus Glycoprotein B Genotypes in Kidney Transplant Recipients in Iran

Background: Cytomegalovirus (CMV) is the most common opportunistic viral infection in kidney transplant recipients. CMV classification is usually based on its glycoprotein B (gB) genotypes, which divides the virus into 4 strains (gB1–4). Objective: To determine the incidence of CMV genotypes in Iran and their relation to various clinical factors. Methods: We studied 80 renal transplant recipients admitted to our transplant referral center between 2014 and 2015. All of the studied patients were monitored every 1–2 weeks for CMV infection by immunofluorescence method. There were 34 CMV-infected patients whose sera were studied with sequencing technique to identify the 4 CMV genotypes. All patients were followed up to 6 months after transplantation. Results: gB1 was the most common genotype (35.3%); it was followed by gB3 and gB4 (each with 17.6 %), gB2, and mixed gB1,3 and gB1,2 (each with 14.7%). Age (p=0.037), time of infection after transplantation (p=0.011), and biopsy-proven rejection (p=0.012) were associated with CMV genotype. After adjusting for covariates, significant associations were found between genotype gB1 and family relationship (p=0.047) as well as HLA mismatch (p=0.014); genotype gB3 and family relationship (p=0.011); and genotype gB4 and age (p=0.019). Conclusion: The most common CMV gB genotype in CMV-infected kidney transplant recipients in Iran was gB1. We recommend considering related therapeutic applications in the management of such patients.