Association between immunophenotypic markers and cytogenetic aberrations in Egyptian patients with plasma cell myeloma

Abstract

Background Plasma cell myeloma is a devastating disease of clonal plasma cells that show considerable diversity both in their immunophenotypic and in their cytogenetic features. Immunophenotyping has been used widely for diagnostic and prognostic evaluation of malignant plasma cells. Aim The aim of this study was to evaluate the relationship between the immunophenotypic profile and standard prognostic factors, and also to determine the correlation between different antigenic expression and the cytogenetic aberrations as well as clinical stage in patients with plasma cell myeloma. Patients and methods A total of 31 newly diagnosed Egyptian patients with plasma cell myeloma were evaluated by multiparameter flow cytometry. Interphase fluorescence in situ hybridization was performed for detection of the expression of the 14q32 immunoglobulin H rearrangement, t(11;14), t(4;14), 13q del, and 17p del on bone marrow samples collected from the patients at diagnosis. Results Positive expression of CD19, CD20, CD13, and CD33 was detected in 38.7, 51.6, 19.4, and 12.9% of patients, whereas CD56, CD45, CD65, and CD117 were expressed in 41.9, 77.4, 9.7, and 25.8% of patients, respectively. A statistically significant correlation was found between CD13 positivity, CD56 positivity, or CD45 negativity and advanced International Staging System (P=0.011, 0.036, and 0.004, respectively). CD33-negative cases were significantly associated with absence of the 14q32 immunoglobulin H rearrangement (P=0.050) and absence of t(4;14) (P=0.018). CD45 positivity and CD13 negativity were correlated with absence of 13q del (P=0.031 and 0.011, respectively). Conclusion Immunophenotypic antigenic expression profile is associated with advanced clinical stage and absence of some cytogenetic aberrations in plasma cell myeloma.