Anti-HLA sensitization in extensively burned patients: extent, associated factors, and reduction in potential access to vascularized composite allotransplantation.

Extensively burned patients receive iterative blood transfusions and skin allografts that often lead to HLA sensitization, and potentially impede access to vascularized composite allotransplantation (VCA). In this retrospective, single-center study, anti-HLA sensitization was measured by single-antigen-flow bead analysis in patients with deep, second- and third-degree burns over ≥40% total body surface area (TBSA). Association of HLA sensitization with blood transfusions, skin allografts, and pregnancies was analyzed by bivariate analysis. The eligibility for transplantation was assessed using calculated panel reactive antibodies (cPRA). Twenty-nine patients aged 32 ± 14 years, including 11 women, presented with a mean burned TBSA of 54 ± 11%. Fifteen patients received skin allografts, comprising those who received cryopreserved (n = 3) or glycerol-preserved (n = 7) allografts, or both (n = 5). An average 36 ± 13 packed red blood cell (PRBC) units were transfused per patient. In sera samples collected 38 ± 13 months after the burns, all patients except one presented with anti-HLA antibodies, of which 13 patients (45%) had complement-fixing antibodies. Eighteen patients (62%) were considered highly sensitized (cPRA≥85%). Cryopreserved, but not glycerol-preserved skin allografts, history of pregnancy, and number of PRBC units were associated with HLA sensitization. Extensively burned patients may become highly HLA sensitized during acute care and hence not qualify for VCA. Alternatives to skin allografts might help preserve their later access to VCA.