Defining the role of skin and mucosal biopsy in facial allotransplantation: A 2-year review and analysis of histology

Background: The implications of allograft skin and mucosal biopsy findings on classification of rejection and treatment remain unclear. Methods: Following facial allotransplantation, scheduled surveillance allograft skin and mucosal biopsy specimens were obtained. Clinical concern for acute rejection prompted biopsies off schedule. Compilation of biopsy results, Banff grading, immunosuppression, and clinical correlation were critically reviewed for a 2-year follow-up. Results: A total of 39 biopsy specimens at 21 time points were obtained for analysis, including allograft skin (n = 21), mucosa (n = 17), and a lesion (n = 1). The patient had three episodes of acute rejection warranting treatment. Discordance between skin and mucosa occurred in 55.6 percent of biopsy specimens (p = 0.01). Mucosa concordance with the clinical evaluation occurred in 38.9 percent of biopsy specimens (p = 0.02), and skin concordance with clinical evaluation was present in 81 percent of biopsy specimens (p = 0.01). Conclusions: The clinical utility of mucosal biopsy remains elusive. The authors' experience suggests that mucosal or skin biopsy, alone, should not drive the decision-making process in treatment. Skin biopsies are more likely to confirm clinical suspicion of rejection than mucosal histology. Data from other institutions are lacking, and future reporting may help elucidate the role of mucosal and skin biopsy in facial allotransplantation.