What Is the Long-Term Effect of CMV Infection After Renal Transplantation?

Abstract

Cytomegalovirus infection is a major cause of morbidity and mortality during the first post-transplant year. However with the current anti-viral prophylaxis the long-term effects of CMV are less likely to be significant. In this study we have retrospectively analysed the impact of a proven CMV viral infection on long-term graft outcomes.A total of 70 renal transplant recipients with CMV infection were identified between 1988 - 2008. To match these patients 136 age, GFR and graft vintage matched controls (CON) were selected from our centre and the two groups were compared for graft survival, patient survival, new onset diabetes mellitus after transplantation (NODAT) and renal function as assessed by serial serum creatinine values and proteinuria. The median time to CMV infection was 3 months (IQR 0-7) with 94% of these occurring within the first post-transplant year. At 10 year follow-up there was no statistically significant difference in the patient survival and NODAT. However, patients with CMV had significantly worse death censored graft survival (P=0.01). Interestingly this difference in graft survival was only significant in patients with superior baseline renal function when compared to those with relatively poor baseline function.Figure: No Caption available.Patients with CMV had significantly worse proteinuria (measured by urine Protein Creatinine Ratio) over a five year follow-up period when compared to the controls (1yr CMV 42, CON 25, P=0.26; 2yrs CMV 56.8, CON 21.4, P=0.07; 3yrs CMV 46.1, CON 29.9, P=0.2; 4yrs CMV 61.8, CON 31, P=0.04; 5yrs CMV 80.5, CON 28.4, 0.02) Serum creatinine was relatively higher in the CMV group (6 months CMV 176, CON 147, p=0.02; 1yr CMV 159, CON 156, P=Ns; 2yr CMV 171 CON 151, P=0.2; 3yr CMV 180, CON 146, P=0.02; 4yr CMV 183, CON 146, P=0.06; 5yr 160, CON 148, P=Ns). We have finally analysed the immediate effect of CMV on haemoglobin. By 1 year from the time of CMV infection, the haemoglobin levels were similar to those without CMV infection.From this retrospective analysis we conclude that the main long-term impact of CMV infection is on allograft function. This was noticed to be more significant in patients with relatively superior baseline renal function.