LONGTERM EFFECT OF SPLENECTOMY VERSUS NO SPLENECTOMY IN RENAL TRANSPLANT PATIENTS

In 1980 we determined the patient and renal allograft survival in 299 kidney transplants recipients who, between 1976 and 1979, were randomized to splenectomy (n=146) versus nonsplenectomy (n=152), and who were treated with antilymphocyte globulin-azathioprine-prednisone for immunosuppression. The preliminary analysis showed significantly (P<.05) better (10 overall, 12 for cadaver, 14 for non identical-related) graft survival rates at two years in splenectomized recipients. The splenectomized patients had higher white blood counts and received more azathioprine and less prednisone. We concluded that splenectomy had a beneficial effect for at least the first two years posttransplant without a detrimental effect on patient survival. Splenectomy, however, remains controversial. Thus, we reanalyzed the original cohort 7 years after the study began and 4 years after the last patient was entered. The reanalysis showed that the differences in graft survival rates between splenectomized and non splenectomized recipients were no longer significant. There were more late deaths from sepsis in the splenectomized group, although the overall patient survival rates were similar in splenectomized and non splenectomized recipients. Splenectomy modestly improved graft survival for the first few years, but the eventual fate of the graft was determined by other factors. The dominant influence on graft survival rates was the source of the kidney (at 6 years in splenectomized recipients the functional survival rate of grafts from HLA-identical siblings was 24 higher than that of grafts from HLA-mismatched relatives, which in turn was 24 higher than that of grafts from cadaver donors; in non splenectomized recipients the difference in 6-year function rates between HLA-identical and mismatched related grafts was 34, and between mismatched related and cadaver grafts was 16. Between 1979 and 1983, we performed pretrans-plant splenectomies in all recipients of renal allografts from HLA-mismatched related or cadaver donors. Two-year graft survival rates were 81 and 68, respectively, in azathioprine-treated recipients, 7 and 12 higher than in the splenectomized patients in the randomized trial. During the same period, splenectomized patients treated with cyclosporine had mismatched related and cadaveric graft survival rates of 86 and 78, respectively. Whether discontinuation of a splenectomypolicy will allow these graft survival rates to be maintained remains to be seen, but we have concluded that indiscriminate splenectomy should not be performed in all renal allograft recipients.