An alternative processing approach to increase CD138 intensity in flow cytometric analysis of plasma cells
Deepak Kumar1, F N U Kiran1, Amanda Wheeler1
1Department of Pathology and Anatomical Sciences, University of Missouri Health Care, Columbia, Missouri, USA.
Background:
Surface median immunofluorescence intensity (MFI) of plasma cells antigens, particularly CD138, by flow cytometry underestimates plasma cell populations when compared with that estimated by morphological assessment on Wright's-stained slides. CD138 MFI using traditional sample preparation methods for flow cytometric analysis is often dim and difficult to interpret due to multiple factors. This becomes critical when diagnosing and accurately classifying plasma cell dyscrasias.
Methods:
In this study, we analyzed 280 flow cytometric results collected from 2016 to 2022 for CD38 and CD138 MFI on bone marrow aspirates performed by two different methods of sample processing-traditional method of lyse-wash and the alternative method of lyse-no-wash.
Results:
Visual examination of histograms showed a clear advantage to CD138 expression intensity with the no-wash method. Although no significant difference was observed in CD38 MFI between the two techniques (p = 0.3), considerable improvement was observed in CD138 MFI with the lyse-no-wash technique of sample processing compared with the conventional method (p = 0.003).
Conclusions:
We concluded that the method of lyse-no-wash is superior to traditional methods especially when it comes to handling bone marrow aspirate samples for plasma cell immunophenotyping. This alternate technique increases the sensitivity of flow cytometry to detect plasma cells resulting in bright and crisp signal intensity for surface CD138. This technique may be particularly advantageous when analyzing low tumor burden such as minimal residual disease.
Insights
The lyse-no-wash method significantly improves CD138 detection in plasma cell immunophenotyping by flow cytometry. This enhanced sensitivity aids in diagnosing plasma cell dyscrasias and detecting minimal residual disease.
Area of Science:
- Hematology
- Immunology
- Clinical Pathology
Background:
- Flow cytometry's surface median immunofluorescence intensity (MFI) for CD138 underestimates plasma cell populations compared to morphology.
- Traditional sample preparation methods yield dim CD138 MFI, complicating plasma cell dyscrasia diagnosis.
Purpose of the Study:
- To compare the efficacy of traditional lyse-wash versus lyse-no-wash sample processing for flow cytometric analysis of CD38 and CD138 MFI.
- To determine if the lyse-no-wash method improves plasma cell detection in bone marrow aspirates.
Main Methods:
- Analysis of 280 flow cytometric results from bone marrow aspirates (2016-2022).
- Comparison of CD38 and CD138 MFI between traditional lyse-wash and alternative lyse-no-wash sample processing methods.
Main Results:
- The lyse-no-wash method demonstrated a clear advantage in CD138 expression intensity.
- A significant improvement in CD138 MFI was observed with the lyse-no-wash technique (p=0.003).
- No significant difference in CD38 MFI was found between the two methods (p=0.3).
Conclusions:
- The lyse-no-wash method is superior for plasma cell immunophenotyping of bone marrow aspirates.
- This technique enhances flow cytometry sensitivity for plasma cell detection, yielding brighter CD138 signals.
- The lyse-no-wash method is particularly beneficial for analyzing low tumor burdens, such as minimal residual disease.
