Association of emergence of HLA antibody and acute rejection in intestinal transplant recipients: a possible evidence of acute humoral sensitization.

Development of HLA antibody has been associated with chronic allograft failure in kidney recipients. We tested HLA antibody in posttransplant sera of intestinal recipients: 126 sera from 28 pediatric recipients were tested for HLA antibody by flow PRA (f-PRA). Median age was 1.1 years (0.44-17). Graft types included isolated intestine (n = 6), liver and intestine (n = 3), modified multivisceral (n = 3), and multivisceral grafts (n = 16). Greater than 10% of either class I (CI) or class II (CII) f-PRA was considered positive, and >30% strongly positive. Five of 28 patients had positive f-PRA in multiple samples; the remaining 23 had either no positive or only one positive sample. Three patients had strongly positive f-PRA. Patients with multiple positive samples were recipients of two modified multivisceral and three multivisceral grafts. Only one of these patients had a positive PRA pretransplant. Cytotoxic cross-match at transplant was negative for all. The three with strongly positive f-PRA showed significant episodes of rejection around the time of positive samples. One of them who persistently had f-PRA value >80% (from day 13-113) died of refractory rejection. The other two had f-PRA of 76% and 53% during the early postoperative course with associated episodes of rejection. F-PRA value decreased with rejection therapy. Only one of the 23 patients (4%) with negative f-PRA had an episode of rejection around the time of sample collection. Development of HLA antibody after intestinal transplantation seems to have significant association with acute rejection episodes.