ISSN 2997-1036
International Journal of Hematology | Vol. 5, No. 11, November 2014 | pp. 81–88
DOI: 10.46882/2014/IJH/000059
Original Article
Title: Immunophenotypic differentiation of plasma cell leukemia from multiple myeloma using CD56 and CD117 expression markers
Names of Authors: W. A. Adebayo¹, X. Y. Emeka², Z. Z. Salami³
Authors’ Affiliations: ¹Department of Haematology, University of Ibadan, Ibadan, Nigeria; ²Department of Haematology, University of Calabar Teaching Hospital, Calabar, Nigeria; ³Department of Pathology, Lagos University Teaching Hospital, Lagos, Nigeria
Abstract: Plasma cell leukemia is an aggressive variant of plasma cell dyscrasia characterized by high numbers of circulating clonal plasma cells. This study investigated the immunophenotypic differences between 10 cases of primary plasma cell leukemia and 45 cases of newly diagnosed multiple myeloma using multiparameter flow cytometry panels targeting CD38, CD138, CD56, and CD117 expression levels. Clonal plasma cells were identified via strong co-expression of CD38 and CD138. CD56 expression was detected in 77.8% (35 of 45) of multiple myeloma patients but was completely absent (0.0%) in all 10 plasma cell leukemia cases (P < 0.001). Similarly, CD117 (c-kit) was expressed in 33.3% of multiple myeloma cases but was negative in the plasma cell leukemia cohort. Conversely, plasma cell leukemia cells displayed a higher density of CD45 and CD19 expression compared to standard intra-medullary myeloma counterparts. The complete absence of CD56 and CD117 coupled with CD45 upregulation marks a distinct immunophenotypic profile for plasma cell leukemia. These biomarkers highlight an altered cell adhesion mechanism that promotes extramedullary escape, assisting pathologists in diagnosing this aggressive hematological condition.
Keywords: Plasma cell leukemia, multiple myeloma, flow cytometry, CD56, CD117, immunophenotyping
Manuscript Timeline: Received: August 20, 2014; Revised: September 25, 2014; Accepted: October 14, 2014; Published: November 19, 2014