Lichen planus-like histopathologic characteristics in the cutaneous graft-vs-host reaction - Prognostic significance independent of time course after allogeneic bone marrow transplantation

Background: The discrimination between acute and chronic graft-vs-host disease (GVHD) after allogeneic bone marrow transplantation (BMT) is important because the treatment regimens and prognosis differ. Objectives: To identify whether accepted histopathologic criteria of a graft-vs-host reaction (GVHR) alone or in combination accurately reflect clinical phase of disease, to correlate patterns with clinical outcome, and to identify any concordance between inflammation and epidermal changes of a GVHR. Design: Skin biopsy specimens were analyzed according to histologically defined standards. Setting: This study was performed in a tertiary care hospital. Patients: One hundred seventy-three skin biopsy specimens (10 days before to 1326 days after BMT) from 83 patients undergoing allogeneic BMT for various malignant neoplasms were selected for study. A consecutive 12-month sample was used. Main Outcome Measures: The main measures in this study were statistical correlations between histopathologic findings and time after BMT, the outcome of BMT, and the correlations between selected histopathologic criteria. Results: Fully evolved histologic features of chronic lichenoid GVHR in the specimens occurred across a nide time range (33-832 days after BMT) and were associated with a 5.6-fold increased risk for death (P=.02) from GVHD. Histologic features of acute GVHR in the specimens also occurred across a wide time range (14-481 days after BMT) and were associated with a 2.2-fold increased risk for death; this finding was not statistically significant (P=.11). Inflammation of the upper dermis was significantly associated with acanthosis and epidermal cell necrosis (P<.001 and P<.001, respectively, for bandlike pattern), confirming the importance of this finding as a criterion for the diagnosis of a GVHR. Blinded evaluation of a subset of specimens for the diagnosis of acute vs chronic GVHR resulted in wide interobserver variation. Conclusions: This study demonstrates the following: specific histologic parameters in skin biopsy specimens do not consistently separate acute from chronic GVHD as defined by days after BMT; independent of time course, fully evolved histopathologic characteristics of a lichen planus-like GVHR is associated with a greater likelihood of death from GVHD; and identification of upper dermal inflammation correlates with the epidermal features of GVHR and should be included in the diagnostic scheme.