The Application of Beckman Coulter VCS Technology at a Major Cancer Center, with Emphasis on the Detection of Circulating Immature Plasma Cells in Plasma Cell Leukemia

Abstract

The St. Vincent's Comprehensive Cancer Center (SVCCC) has a large multiple myeloma program in downtown New York City. The laboratory at SVCCC is an integral part of the diagnosing and monitoring of its myeloma patients. Circulating plasma cells are not a common finding in multiple myeloma. Being able to detect plasma cells in peripheral blood is important because they are a prognostic indicator that correlates with disease progression. Furthermore, the peripheral blood plasma cell population can demonstrate morphologic variability. Immature plasma cells, both plasmablasts and proplasmacytes are associated with more aggressive disease and shortened survival. We encountered 3 multiple myeloma patients with circulating immature plasma cells that appeared as distinct populations on our hematology analyzer's automated white blood cell (WBC) differential. The immature plasma cells, given their unique cellular characteristics, appeared in a common place within the WBC differential scatterplot in each patient. In our laboratory, we have utilized this common graphic pattern to screen for immature plasma cells. This pattern has proven to be a useful tool in our large population of multiple myeloma patients. We have also used examination of the scatterplots in other hematologic malignancies such as chronic lymphocytic leukemia. Using this review policy, the laboratory has been able to achieve a smear review of 25% in our highly abnormal patient population.