Multiple myeloma: an immunologic profile. I. Peripheral blood studies

Area of Science:

• Immunology
• Hematology
• Oncology

Background:

• Multiple myeloma is a hematologic malignancy affecting plasma cells.
• Peripheral blood lymphocytes (PBL) play a crucial role in immune response.
• Understanding immune dysregulation in myeloma is vital for therapeutic strategies.

Purpose of the Study:

• To characterize peripheral blood lymphocytes in multiple myeloma patients.
• To assess immune cell function, including receptor expression and mitogen responses.
• To compare immune profiles of myeloma patients with normal controls and benign monoclonal gammopathy.

Main Methods:

• Flow cytometry for E, EAC, and EA rosette-forming cells, surface immunoglobulin (SIg), and Fc receptors.
• Assessment of lymphocyte proliferation in response to phytohemagglutinin (PHA), concanavalin A (Con A), and pokeweed mitogen (PWM).
• Mixed lymphocyte culture (MLC) to evaluate T cell stimulation and response; cytotoxicity assays against target cells.

Main Results:

• Untreated myeloma patients exhibited normal T cell percentages but abnormal B cell distribution (decreased SIg, increased EAC receptors without SIg).
• Lymphocyte response to PHA, Con A, and PWM, and MLC response were generally normal, but stimulation in MLC was significantly depressed.
• Treated patients showed similar findings, with an additional depression in PWM response; cytotoxicity of PWM-stimulated cells was reduced in both groups.

Conclusions:

• Myeloma patients possess peripheral blood lymphocyte populations with EAC receptors but lacking SIg, impairing MLC stimulation and PWM-induced cytotoxicity.
• These findings establish a baseline for studying abnormal lymphoid function in multiple myeloma.
• Deficiencies in immune cell function may contribute to the pathogenesis and progression of multiple myeloma.