Cytomegalovirus infection among kidney transplant recipients attending Kenyatta national hospital outpatient clinic: a retrospective observational study

Abstract

Background: Cytomegalovirus (CMV) causes significant morbidity and mortality among Kidney Transplant recipients (KTR). Kidney transplant recipients are at risk of acquiring CMV infection and progressing to active disease. Recent studies have shown a marked reduction in all-cause mortality, CMV related mortality and morbidity following antiviral prophylaxis in solid organ transplant recipients (SOTRs). Hence the Kidney Disease Improving Global Outcomes (KDIGO) guidelines have come up with strategies to prevent cytomegalovirus infection (CMVI) and cytomegalovirus disease (CMVD) ultimately improving outcomes among KTR. Study objectives: To determine the prevalence of CMV Infection among KTR Methodology: Study design: Retrospective observational cohort study Setting: Kenyatta National Hospital Transplant Clinic Renal Unit. Subjects: Kidney transplant recipients on follow up in Kenyatta National Hospital, Renal Unit. Materials and methods: Kidney transplant recipients provided data sought for the study. The data was categorized as CMV serology (Donor/Recipient) pre-transplant and CMV clinical disease outcomes post-transplant. Data collection and analysis: Continuous variables are expressed as means and standard deviations, prevalence expressed as percentages with 95% confidence interval. A p value of less than or equal to 0.05 was considered statistically significant. Results: CMV sero-prevalence pre-transplant was very high with 191(97.5%) of recipients and 179 (91.8%) of donors being sero-positive for CMV IgG. None of the donors and recipients had active disease at the time of transplant. CMV serologic pairing at the time of transplant was 180 (92%) concordant positive (D+/R+), 4(2%) concordant negative (D-/R-) and 11(6%) discordant xii pair of D-/R+. None of the R- received graft from a D+. The period prevalence of CMVD post-transplant was 8.2% among these 2.05% had confirmed CMVD and 6.15% had probable CMVD. The median post-transplant period to development of CMVD was 3 months. All patients with confirmed CMVD presented with CMV syndrome. Those with probable invasive CMVD presented with CMV colitis 7(58.3%), CMV hepatitis 2(16.67%) and CMV encephalitis 1(8.3%). Majority of patients with confirmed CMVD died 3(75%) and the remaining one (25%) developed graft rejection and is back on dialysis. Among those with probable disease 5(41.67%) have functioning grafts, 5(41.67%) developed chronic graft dysfunction, 1 (8.3%) developed graft rejection and is on dialysis and 1(8.3%) died of CMV related complications. Conclusions: There is a very high CMV sero-prevalence among KTR in KNH (97.5%) however majority of KTR did not progress to CMVD (8.2%) in the background of no chemoprophylaxis possibly due to a pre-existing cell mediated immunity controlling viral replication. A majority of the patients with CMVD were D+/R+ (93.5%) probably through super infection with reactivation of different CMV genotypes. The impact of CMVD on patients’ outcomes is considerable resulting in reduction in patient survival, graft survival and contributing to graft dysfunction. CMV prophylaxis for all KTR is as a result recommended. CMVD presented in the early pre-transplant period (median 3 months) with non-specific symptoms and hence a high index of suspicion in the early post-transplant period is also recommended.