Quantitative analysis of Langerhans' cells in oral chronic graft-vs.-host disease

Background: The Langerhans cells (LCs) are scattered throughout the epithelium of skin and mucosa and have been associated with the graft‐vs.‐host disease (GVHD), which is the highest cause of morbidity and mortality in patients who underwent bone marrow transplant (BMT). This study aims at quantifying the LCs in the oral chronic GVHD (cGVHD). Methods: Microscopic sections from biopsies carried out in the buccal mucosa of 40 patients who underwent allogenic BMT and developed (20) or not (20) oral cGVHD (Groups 1 and 2, respectively) were utilised. For the control group, free surgical margins of 20 biopsies of non‐inflammatory lesions in the buccal mucosa (Group 3) were used. The sections were studied in routine colouration and immunostained for CD1a. Results: Group 1 (with cGVHD) presented a greater number of Langerhans’ cells/mm2 (50.6 ± 37.2) when compared with the other groups (Group 2, 23.11 ± 19.7; Group 3, 16.6 ± 17.3). Conclusion: Our results suggest a greater recruitment of LCs in patients transplanted with cGVHD, probably as a result of cytokines secreted by the inflammatory cells.