|  | CD81 Protein is Expressed at High Levels in Normal Germinal Center B cells and in Subtypes of Human Lymphomas Robert F Luo, Shuchun Zhao, Robert Tibshirani, June H Myklebust, Mrinmoy Sanyal, Rosemary Fernandez, Dita Gratzinger, Robert J Marinelli, Zhi Shun Lu, Anna Wong, Ronald Levy, Shoshana Levy, Yasodha Natkunam
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					Welcome to the web supplement to the paper:
				
					
						CD81 Protein is Expressed at High Levels in Normal Germinal Center B cells and in Subtypes of Human Lymphomas
					 
					Human Pathology, epub ahead of print (PMID: 20004001)
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	Abstract
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				| CD81 is a tetraspanin cell surface protein that regulates CD19 expression in B lymphocytes and enables hepatitis C virus infection of human cells. Immunohistologic analysis in normal hematopoietic tissue showed strong staining for CD81 in normal germinal center B cells, a cell type in which its increased expression has not been previously recognized. High-dimensional flow cytometry analysis of normal hematopoietic tissue confirmed that among B- and T-cell subsets, germinal center B cells showed the highest level of CD81 expression. In more than 800 neoplastic tissue samples, its expression was also found in most non-Hodgkin lymphomas. Staining for CD81 was rarely seen in multiple myeloma, Hodgkin lymphoma, or myeloid leukemia. In hierarchical cluster analysis of diffuse large B-cell lymphoma, staining for CD81 was most similar to other germinal center B cell–associated markers, particularly LMO2. By flow cytometry, CD81 was expressed in diffuse large B-cell lymphoma cells independent of the presence or absence of CD10, another germinal center B-cell marker. The detection of CD81 in routine biopsy samples and its differential expression in lymphoma subtypes, particularly diffuse large B-cell lymphoma, warrant further study to assess CD81 expression and its role in the risk stratification of patients with diffuse large B-cell lymphoma. |  |