Antigen Expression Patterns of Plasma Cell Myeloma: An Association of Cytogenetic Abnormality and International Staging System (ISS) for Myeloma

Background Immunophenotyping of plasma cell has become an important diagnostic tool for plasma cell myeloma. There have been a few studies for association of antigen expression and cytogenetic abnormality of plasma cell myeloma. Methods A total of 68 symptomatic/smoldering plasma cell myeloma case were analyzed by multicolor flow cytometry using CD38 and CD138 for primary gating of plasma cells. A conventional cytogenetics and fluorescence in situ hybridization (FISH) studies for detection of del(13q) or aneuploidy, del(17p), and IGH/FGFR translocation were done. We statistically analyzed the association of antigen expression and cytogenetic abnormality/myeloma stage (international staging system for multiple myeloma). Results Positive expression of CD19, CD28, CD45, CD56, CD117, and CD274 was detected in 8.8%, 50.0%, 50.0%, 75.0%, 39.7%, and 2.9% of cases, respectively. CD117‐negative cases were associated with hypodiploidy (P = 0.017). CD45‐negative cases were associated with deletion 13 or aneuploidy (P < 0.001) and del(17p)(P = 0.011) by FISH. CD45‐negativity or CD117‐negativity was associated with advanced stage (P = 0.012 and P = 0.016, respectively). Conclusion The antigen expression patterns of myeloma plasma cell were associated with cytogenetic abnormality and stage.