The bone marrow plasma cell labeling index by flow cytometry
1Institute of Haematology, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia.
Cytometry
|December 10, 1999
Summary
Flow cytometry offers a faster, more objective method for assessing multiple myeloma prognosis. This technique improves upon traditional microscopy by providing more reliable plasma cell labeling index values.
Area of Science:
- Hematology
- Immunology
- Oncology
Background:
- The bone marrow plasma cell labeling index is crucial for multiple myeloma prognosis.
- Traditional immunofluorescence microscopy is time-consuming and subjective.
Purpose of the Study:
- To evaluate flow cytometry adaptations for assessing the plasma cell labeling index.
- To compare different methods for S-phase detection and plasma cell identification.
Main Methods:
- Compared bromodeoxyuridine and propidium iodide methods for S-phase detection.
- Compared CD38-FITC, CD38-FITC + CD138-FITC, and CD38-biotin + streptavidin FITC for plasma cell identification.
- Correlated flow cytometry results with traditional microscopy.
Main Results:
- CD38-biotin + streptavidin FITC demonstrated superior fluorescent intensity for plasma cell identification.
- Propidium iodide staining correlated well with microscopy (r=0.71, P<0.0001).
- Bromodeoxyuridine method showed no correlation with microscopy (r=0.09, P=NS).
- Flow cytometry methods yielded higher labeling index values than microscopy.
- A new threshold of >4% labeling index is proposed, replacing the traditional >1%.
Conclusions:
- Flow cytometry provides a more objective and efficient method for determining the plasma cell labeling index in multiple myeloma.
- The propidium iodide DNA method combined with CD38-biotin + streptavidin FITC is a superior flow cytometry approach.
- This enhanced method offers additional prognostic data, including ploidy and cell cycle status.
