The effect of HLA mismatch on highly sensitized renal allograft recipients

We examined the effects of increasing human leukocyte antigen (HLA) mismatches (MM) on long-term graft outcomes in patients transplanted with a panel reactive antibody (PRA) >80% over a 10-yr period.

A total of 142 recipients were divided into three groups based on the number of HLA MM with their allograft (0-2, 3-4 and 5-6 MM; Groups I, II and III). All patients received the same immunosuppression protocol.

The higher MM groups had a higher incidence of rejection (4.4% vs. 11.4% vs. 31.3%, p < 0.01). A multivariate analysis showed that rejection was the only significant variable affecting graft loss (OR = 7.45, p = 0.01). There was a trend toward more CMV infection and worse graft function with higher MM. Kaplan-Meier five-yr graft survival estimates were 100% vs. 81% vs. 74% for Groups I, II and III, respectively (p = 0.14).

In patients with PRA levels >80%, a higher HLA MM is associated with higher incidence of acute rejection. Acute rejection was the only significant variable affecting graft loss. We found a trend toward more CMV infections and worse graft outcomes with higher MM. Closer HLA matching and immunologic monitoring needs to be considered to improve graft outcomes among sensitized recipients.