#2458 Factors associated with cytomegalovirus infection in kidney transplant patients: analysis from a nationwide registry data

Abstract Background and Aims Cytomegalovirus (CMV) has had a significant impact on solid organ transplantation. It can affect allograft function and increase patient morbidity and mortality. We have made several efforts to prevent CMV infection after kidney transplantation (KT), but we have not yet been able to prevent it satisfactorily. Drugs were used as preventive therapy or preemptive therapy, but they did not completely prevent the diseases. Therefore, it will be possible to reduce CMV infection by taking actions against factors that can easily cause CMV infection. We investigated factors that make CMV infection more likely and explored the effects of CMV infection using The Korean Organ Transplantation Registry (KOTRY) datasets. Method We used the data from the KOTRY datasets. A total of 7545 KT recipients were analysed. Results The mean age of the subjects was 49.7 ± 11.5 years (range, 19-80). Among the 7545 subjects, 58.6% were male. Three hundred and twenty-four (4.2%) subjects had CMV infection (CMV group). There were 4827 (64%) living donors, 2717 (36%) cadaveric donors, and 1338 (17.3%) ABO incompatible donors. Of the total, 95% were transplanted from positive to positive CMV IgG, and 1.9% were from positive to negative. Although preventive treatment is performed in the second cases, in most cases preemptive therapy is performed. The age was 49.6 ± 11.5 in the no CMV group and 51.4 ± 12.6 in the CMV group (P = 0.013). There was no difference in sex, weight and BMI in both cases. The causes of end stage renal disease were glomerulonephritis, DM, and hypertension in that order, and there was no difference in the rates of diabetes and hypertension between the two groups. There was no difference in the desensitization rate at 24% in the no CMV group and 23% in the CMV group. At the time of discharge after surgery, the tacrolimus dose was 6.4 mg/d±3.6 in the no CMV group and 6.3 ± 3.8 mg/d in the CMV group (P = 0.89). Tacrolimus concentration (C0) was 8.0 ± 2.6 ng/ml in the no CMV group and 8.9 ± 2.4 ng/ml in the CMV group. It was higher in the CMV group (P = 0.002). When divided into 3 tertiles based on C0, the break points were 6.7 and 8.9 ng/ml. There was a higher incidence of CMV in the third tertile group compared to the first and second tertiles, but there was no difference between the first and second groups. When the metabolic rate (tacrolimus concentration divided by dose) was divided into three groups, CMV occurred more frequently in the group with the lower metabolic rate, at 3.9% in the group with the lowest tertile and 2.3% in the highest tertile (P = 0.046). At 6 months, tacrolimus dose was 4.3 ± 2.4 mg/d in the no CMV group and 3.9 ± 2.3 mg/d in the CMV group, which was lower in the CMV group (P = 0.005). Tacrolimus concentration was 6.8 ± 2.4 ng/ml in the no CMV group and 6.4 ± 2.3 ng/ml in the CMV group, which was lower in the CMV group (P = 0.004). There was no difference according to metabolic rate. At discharge (62.5 ± 25.7 vs. 54.5 ± 26.5), at 6 month (56.0 ± 22.3 vs. 47.9 ± 19.0), and at 1 year (57.2 ± 20.0 vs. 48.8 ± 19.6 mL/min/1.73 m2), eGFR in the No CMV group was higher than that in the CMV group (P 0.005). One thousand two hundred and sixty-four (16.8%) patients showed acute rejection within 1 year. Acute rejection occurred within 1 year in 36.4% of the CMV group and 15.9% of the no CMV group (P 0.001). Delayed graft function occurred in 4.6% of the CMV group and 5.5% of the no CMV group (P 0.001). Conclusion CMV was more common in older people, those with higher tacrolimus concentrations, and those with lower tacrolimus metabolic rates. The risk increases when the concentration exceeds 8.9 ng/ml, and after reducing the dose, the dose and concentration were lower in the CMV group at 6 month and 1 year. Although the dose was later reduced in the CMV group, more acute rejections occurred within 1 year, which suggests that CMV infection can trigger rejections. Delayed graft function occurred less frequently in the CMV group, which may be related to the higher concentration of tacrolimus.