Clinical determinants of multiple acute rejection episodes in kidney transplant recipients

Background. Recipients with multiple (more than one) acute rejection (AR) e pisodes have significantly lower graft survival rates than those with no AR or only one treated episode. However, fewer than 50% of recipients treated for one AR episode will have another episode. Methods, We studied recipients with at least one AR episode to determine wh ether any clinical features could identify risk factors for multiple AR. Results, Between January 1, 1984, and June 30, 1997, a total of 1793 recipi ents underwent a kidney transplant at our institution. Of these, 354 were t reated for one AR episode, 307 for more than one. By multivariate analysis, recipients at highest risk for multiple AR episodes were those with initia l delayed or slow graft function (relative risk=1.5, P=0.05), those with in itially severe AR (as judged by vascular involvement or steroid resistance) , and those with an initial early AR episode (<6 months posttransplant). Th e remaining variables tested were not significant. Graft survival in recipi ents with more than one AR episode was significantly lower than in those wi th only one AR episode. Graft survival at 5 years posttransplant was 52.5% in recipients with more than one AR episode and 85.1% in recipients with on e AR episode (P=0.0001), Chronic rejection as a cause of graft loss was sig nificantly more common in recipients with more than one vs. only one AR epi sode (34.8% vs. 8.9%, P=0.001), Conclusion. Clinical features may be used to identify recipients at higher risk for multiple AR episodes. These recipients can then be targeted with m ore aggressive or novel immunosuppressive regimens in an attempt to reduce the likelihood of another AR episode.