Correlation of pretransplant PRA level and presensitization against HLA class I and class II antigens on graft and patient outcome in primary kidney transplant recipients .

161 primary kidney transplant recipients were retrospectively analyzed to compare graft and patient outcome among patients with PRA levels of <10 percent, ID-29 percent, 30-59 percent, and 60 percent or higher and to determine whether the presence of pre-transplant PRA levels of 10 percent or higher to both class I and class II HLA antigens, or to either class I or class II HLA antigens alone, are associated with poorer graft and patient survival at 1 year. Graft survival was highest among patients with a PRA level of <10 percent (93 percent) compared to patients with a PRA level of 10-29 percent, 30-69 percent, and 60 percent and higher with survival rates of 91 percent, 33 percent, and 67 percent respectively. A markedly significant decrease in graft survival in patients with an intermediate degree of sensitization (PRA level of 30 percent to 59 percent) was found as compared to patients with a PRA level of <30 percent. (p=0.001) There was a statistically significant increase in the episodes of acute rejection (p=0.001) in the former group as compared to the latter. Moreover, rejection episodes appeared earlier. There was no significant correlation however, between the PRA level and patient mortality or the severity of acute rejection. Graft survival at 1 year was significantly lower in patients with a PRA level of 10 percent or higher to both or either HLA class as compared to patients with a PRA level of <10 percent to both or either class alone (p=0.018). Acute rejection episodes appeared earlier and more frequent in the former group compared to the latter. Severity of rejection among groups was not statistically significant (p=0.130). Mortality rates at 1 year did not differ between the sensitized and unsensitized groups, (p=1.000).

CONCLUSION: Pretransplant PRA levels have a negative impact on renal transplant outcome. Presensitization to both or either class of HLA antigens are associated with poorer graft outcome.