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.