FIT AND MATCH HYPOTHESIS FOR KIDNEY-TRANSPLANTATION

The importance of HLA matching for cadaver-donor transplants is often ignored due to the small (10%) difference in graft survival rates betw een the best and worst matched pairs. A new ''fit and match'' hypothes is is proposed to improve the predictive value of matching. Graft and functional survival rates of kidney transplants were calculated for li ving and cadaver-donors by the standard Kaplan and Meier methods. Mean discharge serum creatinine (SCr) values were computed after excluding patients who died or lost their grafts before discharge. Donor size, recipient size, age of donor kidney, damage caused by cold ischemia ti me, and mode of donor death all had substantial effects on the average SCr levels at discharge. These SCr levels correlated with one- and fi ve-year graft survival rates. Transplants that had extremely different graft survival rates, such as those from living donors and cadaver do nors, were found to have similar rates when reclassified by SCr levels at discharge. By examining the combined effects of the fit and match factors, transplants with the best fit and match exhibited a 95% one-y ear graft survival rate, whereas those with the worst fit and match ha d a 75% survival rate. This 20% difference increased to 36% after five years (84% vs. 48%). We conclude that the fit and match hypothesis pr ovides a theoretical basis for devising a more critical method of pred icting cadaver kidney transplant survival rates. Furthermore, it sugge sts a vital need to develop methods for estimating functional donor re nal mass.