The standard diagnosis of multiple myeloma by flow cytometry is based on selection of population of CD38+/CD138+ positives cells. As the result treatment with proteasome inhibitors, CD138 may be underexpressed on atypical plasma cells. Thus, in order to improve this strategy, recently new CD138-independent method, based on CD38 positivity of plasma cells was developed. We present an unusual case of CD138- negative multiple myeloma which had become double CD138-/CD38- negative after treatment with daratumumab by which we would like to illustrate potential pitfalls of both strategies.
Keywords: CD138; CD38; Daratumumab; Flow cytometry; Multiple myeloma; Proteasome inhibitors.
Copyright © 2017 King Faisal Specialist Hospital & Research Centre. Published by Elsevier Ltd. All rights reserved.