Absence of immunization effect in human-kidney retransplantation

We examined whether rejection of a previous graft rendered a recipient immunized against subsequent kidney transplants in over 1900 retransplants. The one-year survival rate (43 +/- 1 per cent [ +/- S.E.M.]) of second grafts from cadaver donors was only slightly (but statistically significantly) lower than that of first transplant (47 +/- 1 per cent, P less than 0.02). Repeated HLA mismatches in 180 second transplants did not show a lower survival rate than 925 grafts with no repeated HLA incompatibility. We conclude that the danger of immunization by previous grafts has been overemphasized from studies in laboratory animals. Those who rejected the first graft rapidly (high responders) had significantly shorter survival of the second graft compared with those who rejected the initial graft slowly (low responders) (60 +/- 3 versus 31 +/- 3 per cent at one year, P less than 0.00001).