Association of vitamin D receptor FokI and ApaI polymorphisms with human cytomegalovirus disease in the first three months following kidney transplantation.

Background: Untreated human cytomegalovirus (CMV) disease (CMVD) is an identified risk factor for reduced rates of patient (and graft) survival, death or retransplantation in kidney transplant recipients due to increased immunological tolerance after transplant. Vitamin D receptor (VDR) gene polymorphisms have an obvious relationship with autoimmune diseases but the relationship between VDR gene polymorphisms and CMVD are not well understood. This study investigated the relationship between VDR FokI and ApaI gene polymorphisms and CMVD, and their value for predicting risk of CMVD.

Methods: Ninety-eight kidney transplantation recipients were randomly chosen for which peripheral blood samples and case histories for the first three months after kidney transplantation were obtained. Using polymerase chain reaction-restriction fragment length polymorphisms, 30 recipients were found to be homozygous for the FokI gene (FF), 47 heterozygous (Ff), and 21 were homozygous (ff). Likewise, similar analyses determined that 12 recipients were homozygous for the ApaI gene (AA), 36 heterozygous (Aa), and 50 homozygous (aa). Factors affecting the prognosis of the kidney transplantation were compared for all genotypes by statistical analysis before operation. Infection by CMV for all recipients was detected by immunofluorescence assay to diagnose CMVD.

Results: No statistical significance was observed for the factors affecting the prognosis of the kidney transplantation between both genotypes; however, statistical differences in CMVD among the FokI genotypes were identified. It was determined that the risk of CMVD was significantly increased for recipients of the ff genotype than for other genotypes. There was no statistical significance observed for CMVD among ApaI genotypes.

Conclusions: The recessive f allelic gene of VDR can be regarded as a risk factor of CMVD while FF recipients have lower incidence of CMVD after kidney transplantation. ApaI genotypes showed no relationship with predisposition to CMVD.