[Skin biopsy in diagnosis of chronic graft-versus-host disease in patients after allogeneic haematopoietic stem cell transplantation: pathologist's point of view on quantitative scoring system].

BACKGROUND: Pathology diagnosis of chronic graft-versus-host-disease (GVHD) after allogeneic haematopoietic stem cell transplantation (allo-HSCT) is an important issue in clinical follow-up, in spite of frequent difficulties in interpretation., related to dynamic changes occurring in the skin during the disease, as well as to sequelae of basic disease and immunosuppressive therapy. Recently presented Consensus NIH (National Health Institute, Bethesda, USA) of histopathologic (HP) analysis is still complex and intrinsically divergent, thus clinically difficult to implement. OBJECTIVE: Analysis of clinical value of histological evaluation results of skin biopsy in children after allo-HSCT and its correlation with clinical status. PATIENTS AND METHODS: Ten skin biopsies were taken from 7 patients (4 boys, 3 girls, age 3-15 years) after allo-HSCT (6 MFD, 1 MMUD) and analyzed after hematoxylin/eosine and immunohistochemical (CD3, CD45T, CD20) staining. Pathology analysis was based on commonly accepted criteria enabling simple and unambiguous interpretation. Results were compared with clinical data and indications for immunosuppressive therapy. RESULTS: It was found that reliable and coherent interpretation can be made when following parameters were taken into account: 1. in epithelium: the presence of apoptosis, archetypical changes and vacuolar degeneration in the basilar layer, presence of CD3/CD45 in the epidermis; 2. in the dermis: the extent of collagenization, presence of melanophages and lymphocyte infiltrations; 3. in the eccrine glands epithelium: eccrine glands atrophy and presence of lymphocytes. CONCLUSIONS: A new scoring system of skin biopsy analysis in patients with chronic GVHD based on the modified NIH Consensus was proposed. The preliminary clinical value of histological results was assessed. Skin biopsy evaluation based on limited qualitative and quantitative analysis of lymphocyte infiltrates together with studies on intensity of apoptosis, collagenization and archetypical changes is a valuable diagnostic method complementary to clinical records, enabling easier undertaking of therapeutic decisions.