Aberrant Expression of ID2 protein and its correlation with EBV-LMP1 and P16(INK4A) in Classical Hodgkin Lymphoma in China

Samples of classical Hodgkin lymphoma from 60 Chinese patients were analyzed for the expression of ID2, EBV-LMP1 and p16(INK4A) proteins by immunohistochemistry.ID2 protein was expressed in 83.3% of this group of classical Hodgkin lymphoma, staining strongly in both cytoplasm and nucleus of the Hodgkin and Reed-Sternberg (HRS) cells. EBV-LMP1 and P16(INK4A) were overexpressed in 85.0% and 71.7% of Hodgkin lymphoma, respectively. EBV-LMP1 was noted in the cytoplasm, membrane and nucleus of HRS cells; P16(INK4A) was in the nucleus and cytoplasm. Microscopically, ID2, EBV-LMP1 and P16(INK4A) staining distinguished the HRS cells from the complex background of lymphocytes. ID2 was positively correlated with EBV-LMP1(P < 0.01), but P16(INK4A) was inversely related to EBV-LMP1 (P < 0.05).It is suggested that ID2, EBV-LMP1 and P16(INK4A) could play an important role in the evolution of classical Hodgkin lymphoma, and be considered as potential adjunct markers to identify HRS cells in diagnosis.Hodgkin lymphoma comprises two distinct entities; namely nodular lymphocyte predominant Hodgkin lymphoma and classical Hodgkin lymphoma. Classical Hodgkin lymphoma is a lymphoid neoplasm composed of monoclonal Hodgkin cells and multinucleated Reed-Sternberg (HRS) cells residing in an infiltrate containing a variable mixture of non-neoplastic small lymphocytes, eosinophils, neutrophils, histiocytes, plasma cells, fibroblasts and collagen fibres. [1] There are four morphological variants of classical Hodgkin lymphoma, namely nodular sclerosis, mixed cellularity, lymphocyte-rich and lymphocyte-depleted. HRS cells are currently thought to be derived from mature B cells at the germinal stage of differentiation, and are pathognomonic in Hodgkin lymphoma. [1] However, HRS cells may often be scanty and difficult to identify in sections. The pathogenesis of classical Hodgkin lymphoma remains unknown.ID proteins are key regulators in several developmental and cellular processes. In general, abe