Objective: To explore the expression of B-cell-specific activator protein (BSAP) of H/RS cell in classical Hodgkin's lymphoma (cHL).
Methods: Immunohistochemical method was used to detect the expression of BSAP in 33 samples of formalin-fixed, paraffin-embedded tissues of cHL. Nine samples of lymph node of reactive hyperplasia, 10 samples of B-cell lymphoma, and 10 samples of T-cell lymphoma were also detected as BSAP controls. Mouse-anti-human monoclonal antibodies CD20, CD30 and CD15 were detected among the cHL cases as routine comparison.
Results: 30 of 33 (90.91%) cases of cHL were BSAP expression positive in H/RS cells, while all of the 33 (100%) cases of background B-lymphocytes were BSAP positive. Almost all B cells of lymph node reactive hyperplasia were BSAP positive. All malignant cells in B-cell lymphoma were BSAP positive, while all malignant cells in T-cell lymphoma were BSAP negative. Among the 33 cases of cHL there was a significant difference between the expression of BSAP and the expression of CD20 (30.30%) in H/RS cells (P = 0.000), and no significant difference between the expression of CD30 (93.94%) and CD15 (75.75%, P = 0.082).
Conclusion: The frequent expression of BSAP in H/RS cells of classical Hodgkin's disease provides further evidence for its B-cell origin and helps to identify H/RS cells. The expression of BSAP in H/RS cells can be used to distinguish HL from anaplastic large cell lymphoma (ALCL).