The Importance of CD319 Marker in Diagnosis and Prognosis of Plasma Cell Myeloma Patients

Abstract

Background: The surface antigen CD319 (CS1,SLAMF7) is a marker of normal and malignant plasma cells in plasma cell myeloma. It is encoded by the SLAMF7 gene that located on chromsome 1 on long arm (1q23.3). It acts as a human NK cell receptor which its function activated through homophilic interactions.In contrast to CD138 (the traditional plasma cell marker), CD319/SLAMF7 is much more stable and allows proper isolation of malignant plasma cells from delayed or even cryopreserved samples. So SLAMF7 expression (CD319) play an important role in diagnosis of plasma cell myeloma. This study aimed to evaluate the use of CD319 as a diagnostic and prognostic marker of plasma cell myeloma. Methods: This is a Cohort study . It was conducted on newly diagnosed plasma cell myeloma patients at Internal Medicine Department-Hematology unit at Zagazig University Hospitals and Clinical Pathology Department .It included 18 cases (11 males and 7 females) with a male to female ratio of 1.5:1. Mean age of cases was 53 ± 9.8 years. Patients were followed up three months later after initiation of treatment. The study started at February 2019 to February 2021. Results: This study showed that CD319 (SLAMF7, CRACC, CS1) is a stable marker with high expression (MFI) on normal and malignant plasma cells. In this study , CD319 is found positive in all PCM patients . Low expression of CD319 (if MFI below 128.3) associated with a significant better response to treatment and good prognosis but high expression of CD319accompanied by bad response to treatment. It can be effectively used as a diagnostic and prognostic marker for PCM. Conclusion: CD319 is found positive in all PCM patients and shows strong positive correlation with CD138/CD38 and CD56 . It can be effectively used as a diagnostic marker for PCM. Low expression of CD319 associated with a significant better response to treatment. This indicates importance of CD319 as a prognostic marker of PCM .