RT Journal Article
SR Electronic
T1 Comparison of laboratory methods for the detection of neoplastic plasma cells in plasma cell dyscrasias
JF Journal of Clinical Pathology
JO J Clin Pathol
FD BMJ Publishing Group Ltd and Association of Clinical Pathologists
SP jcp-2022-208446
DO 10.1136/jcp-2022-208446
A1 Robin Dietz
A1 Trang K Lollie
A1 Tracie Goh
A1 Nagesh Rao
A1 Sheeja Pullarkat
YR 2022
UL http://jcp.bmj.com/content/early/2022/08/31/jcp-2022-208446.abstract
AB Aims To compare the ability of immunohistochemistry (IHC), multiparameter flow cytometry (MFC) and fluorescence in situ hybridisation (FISH) to detect clonal plasma cells. We also attempted to outline a testing strategy for monitoring multiple myeloma patients.Methods A retrospective review was performed on 278 CD138+sorted FISH studies from November 2019 to December 2020 along with their concurrent IHC and MFC results. A p value was computed using McNemar’s test for paired data. Association was calculated using the non-parametric Spearman correlation coefficient.Results Using the Mc Nemar’s test for paired data, CD138+sorted FISH studies achieved the highest proportion of positive results and was significantly greater than MFC (63% vs 53%, p=0.01). FISH had more positive results than IHC, although this did not reach statistical significance (60% vs 57%, p=0.34). IHC and MFC had high correlation and high agreement (90.3% agreement, kappa=0.805, p<0.0001). CD138+sorted FISH studies achieved the highest proportion of positive results relative to IHC and MFC, indicating that it may be a reliable marker for clonal plasma cell detection.Conclusions While CD138+sorted FISH is primarily used for prognostication, it may be employed as a single test for detection and monitoring clonality in certain scenarios. Further studies are needed to monitor the outcomes of patients with positive FISH and negative IHC and MFC. Additionally, there was high agreement between IHC and MFC, suggesting that performing both tests may not be necessary.