Are the current chronic allograft nephropathy grading systems sufficient to predict renal allograft survival?

Factors affecting eGFR 5-year post-deceased donor renal transplant: analysis and predictive model

AIM

Long-term survival of renal allografts has improved over the last 20 years. However, less is known about current expectations for long-term allograft function as determined by estimated glomerular filtration rate (eGFR). The aim of this study was to investigate factors which affect graft function at 5 years' post-renal transplantation. The statistically significant factors were then used to construct a predictive model for expected eGFR at five years' post-transplant.

METHODS

We retrospectively reviewed all adult patients who received a renal transplant in the Republic of Ireland between 1990 and 2004. Data collected included era of transplantation (1990-1994, 1995-1999, 2000-2004), donor and recipient age and gender, number of human leucocyte antigen mismatches, cold ischemia time (CIT), number of prior renal transplants, immunosuppressive regimen used and acute rejection episodes. Estimated GFR was calculated at 5 years after transplantation from patient data using the Modified Diet in Renal Disease (MDRD) equation. Consecutive sampling was used to divide the study population into two equal unbiased groups of 489 patients. The first group (derivation cohort) was used to construct a predictive model for eGFR five years' post-transplantation, the second (validation cohort) to test this model.

RESULTS

Nine hundred and seventy eight patients were analyzed. The median age at transplantation was 43 years (range 18-78) and 620 (63.4%) were male. One hundred and seventy five patients (17.9%) had received a prior renal transplant. Improved eGFR at five years' post-transplantation was associated with tacrolimus-based combination immunosuppression, younger donor age, male recipient, absence of cytomegalovirus disease and absence of acute rejection episodes as independently significant factors (p < 0.05). The predictive model developed using these factors showed good correlation between predicted and actual median eGFR at five years. The model explained 20% of eGFR variability. The validation model findings were consistent with the derivation model (21% variability of eGFR explained by model using same covariates on new data).

CONCLUSION

The predictive model we have developed shows good correlation between predicted and actual median eGFR at five years' post-transplant. Applications of this model include comparison of current and future therapy options such as new immunosuppressive regimens.

Current status of renal transplantation from HCV-positive donors

Hepatitis C virus (HCV) infection remains frequent among renal transplant (RT) recipients and has a detrimental effect on patient and graft survival. accelerated progression of liver disease due to HCV has been implicated in increased mortality after kidney transplantation but additional outcomes have been related to HCV after RT. all HCV-infected kidney transplant candidates should be considered for liver biopsy before RT. HCV infection should not be considered an absolute contraindication to renal transplantation, although the course of HCV-related liver disease is often progressive. Numerous organ procurement organizations have introduced the policy of accepting kidneys from HCV-positive donors for HCV-positive recipients, but this is still controversial. Single-center experiences have not reported adverse effects on the short-term patient and graft survival, however information from large databases has suggested that RT recipients of HCV-positive donors are independently at risk of mortality even in the modern era of immunosuppression. Renal transplantation should be considered using HCV-seropositive grafts for qualified patients with chronic kidney disease (CKD) stage 5 and HCV infection since good information indicates that the transplantation of kidneys from HCV-infected donors results in improved survival compared to wait-listed and dialysis-dependent candidates. a potential risk related to the use of donor HCV-positive kidneys cannot be excluded, and kidneys from HCV-infected donors should be restricted to recipients with evidence of active viremia at the time of kidney transplantation.