Study of Cytomegalovirus Infection in Renal Transplant Recipients Who had IgG CMV Antibody in the Pretransplantation Period

Kahng, Kyoung Won; Kang, Chong Myung

Abstract

Cytomegalovirus(CMV) infection occurs more frequently in renal transplant recipients than in the normal population. But the incidence and severity of CMV infection and antibody positivity are different between countries. We studied the incidence of CMV infection with a long term follow up in renal transplant recipients who were IgG CMV positive and whose donors were also IgG CMV positive preoperatively. We studied the difference and usefulness of various detection methods including IgM CMV antibody by ELISA, shell vial culture, and quantitative dual polymerase chain reaction(PCR). We also studied possible factors that may affect CMV infection and the function of the grafted kidney in CMV infected patients. This study included 36 patients, 20 males and 16 females, who received renal transplantation at Hanyang University Hospital between July, 1994 and March, 1995. IgG and IgM CMV antibodies were detected and shell vial cultures were performed in recipient candidates and donor candidates preoperatively. Postoperatively, we checked IgM CMV and performed shell vial cultures in renal transplant recipients every month after the operation and when CMV infections were suspected. We also performed dual PCR with endpoint titration to quantify the amount of CMV DNA. The total incidence of CMV infection was 30.6% (11 patients among 36 patients). Three patients had CMV disease, and only one patient was severe enough to need gancyclovir therapy. The average onset of infection was 12.9 weeks after the operation(earliest 5weeks-latest 33weeks). In all patients with CMV disease, CMV positivity appeared by all three detection methods. But detection time and duration of positivity were different. The amount of CMV DNA in patients with active CMV disease was higher than those of asymptomatic patients and one patient following antiviral therapy. Age, sex, donor type, HLA matching and rejection did not affect CMV infection. Incidence of CMV infection was higher in patients who were transfused within 3 weeks before the operation(6/8 vs 5/28, p=0.048). Changes of creatinine level from initial outpatient department(OPD) visit to last OPD visit which were corrected by OPD follow up time showed no significant difference between CMV infected and non-infected patients In conclusion, the incidence of CMV infection and disease was relatively low, and the degree of disease severity was mild. In our renal transplant recipients, CMV infection may not be a serious problem. Quantitative dual PCR using end-point titration is a good method to detect CMV infections and monitor the clinical course. Because it is easy to use, detect disease earlier and can quantify the amount of CMV DNA. Among various factors, transfusion affected CMV infection significantly in our patients. In an average of 231 days of OPD follow up time, CMV infected patients showed no impairment of grafted kidney function, but a more long term follow up is needed.