Immunohistochemical Expression of CD47 and Signal Regulatory Protein-α in B-Cell Lymphoma

Background: Lymphoma is one of many tumors that develop mechanisms to avoid the immune system. One mechanism of immune system evasion is CD47 interaction with various ligands, including signal regulatory protein alpha (SIRP-α). This interaction inhibits phagocytosis of lymphoma cells. Objectives: To assess and compare the frequency of combined immunohistochemical expression of CD47 and SIRP-α in B cell lymphomas in addition to studying its association with some clinicopathological parameters. Methods: A retrospective and prospective case series study of 51 cases of B-cell lymphomas collected randomly from the histopathological department of governmental and some private laboratories in Nineveh Province over a period of six months extending from September 2024 to February 2025. An immunohistochemistry investigation using CD47 and SIRP-α was performed, and the positive expression data were evaluated. Results: The mean age was 31.29 years for HL and 62 years for NHL, with slight male predominance (51%) and (66.67%) had nodal presentation. B-cell lymphoma cases included in this study show immunohistochemical expression of CD47 and SIRP-α, but with different staining grades. 64.71% and 33.33% were high expressors vs. 35.29% and 66.67% were low expressors for CD47 and SIRPA, respectively, with no significant association. Conclusions: Although CD47 and SIRPα showed divergent results, this study revealed that most B-cell lymphomas express CD47 and SIRPα proteins independently.