Analysis and detection of B cell neoplasms

Area of Science:

• Immunology
• Hematology

Background:

• B cell lymphomas are cancers of white blood cells that can be difficult to detect.
• Current diagnostic methods may not identify very small numbers of tumor cells.

Purpose of the Study:

• To describe the use of fluorescence-activated cell sorting (FACS) for sensitive detection of B cell lymphoma cells.
• To establish criteria for identifying tumor cells within normal cell populations using FACS.

Main Methods:

• Analysis of human B cell lymphoma cells using FACS.
• Quantification of surface kappa or lambda immunoglobulins (Ig) for tumor cell identification.
• Comparison of normal and tumor cell fluorescence patterns.

Main Results:

• Tumor cells identified by a 'clonal excess' of a single light chain type at specific fluorescence intensities.
• Detection of as few as 1% tumor cells in chronic lymphocytic leukemia and 0.1% in lymphoma.
• Circulating tumor cells identified in most B cell lymphoma patients with normal cytologic analysis.

Conclusions:

• FACS is a highly sensitive method for detecting B cell lymphoma cells.
• Subclinical leukemia is frequently present in B cell lymphomas.
• FACS can identify minimal residual disease and aid in diagnosis.