T-cell involvement in benign phase chronic myelogenous leukemia.

Area of Science:

• Hematology
• Oncology
• Immunology

Background:

• Chronic myeloid leukemia (CML) is characterized by the Philadelphia (Ph1) chromosome.
• Therapeutic interventions aim to reduce Ph1-positive cells in CML patients.
• The presence of the Ph1 abnormality in T cells is not fully understood.

Purpose of the Study:

• To investigate the presence and extent of the Philadelphia (Ph1) chromosome abnormality in T cells from chronic myeloid leukemia (CML) patients.
• To determine if Ph1-positive T cells persist despite therapy-induced reduction of Ph1-positive cells in bone marrow.

Main Methods:

• Peripheral blood T cells from CML patients were cultured and expanded.
• T cell populations were analyzed for the E-rosette receptor using monoclonal antibody OKT11.
• Simultaneous cytogenetic analysis was performed to detect Philadelphia (Ph1) metaphases in T cell cultures and bone marrow.

Main Results:

• T cell cultures were confirmed to be over 99.5% T cells via OKT11 analysis.
• Ph1 metaphases were detected in T cell suspensions from four out of seven CML patients (ranging from 6% to 14%).
• Ph1-positive T cells were identified even when bone marrow exhibited minimal or no Ph1-positive metaphases due to interferon or chemotherapy.

Conclusions:

• A minority of T cells in benign phase CML harbor the Philadelphia (Ph1) chromosome abnormality.
• The Ph1 abnormality can be detected in T cells independently of the bone marrow status, particularly during therapy.