T- and B-cell responses in patients with malignant pleural effusions

Area of Science:

• Immunology
• Oncology
• Cell Biology

Background:

• Pleural effusions are fluid accumulations in the thoracic cavity, often associated with various conditions including cancer.
• Understanding the immunological characteristics of lymphocytes within pleural effusions is crucial for diagnosing and managing diseases.

Purpose of the Study:

• To compare immunological and cellular features of lymphocytes in pleural effusions and blood from cancer patients, benign effusions, and healthy donors.
• To investigate differences in immunoglobulin and total protein levels in effusions and serum.
• To assess lymphocyte proliferation and T-cell/B-cell content.

Main Methods:

• Analysis of cytological features, rosette-forming capacity, immunofluorescent staining, and PHA-stimulated DNA synthesis in lymphocytes.
• Quantification of total protein and immunoglobulin (IgG, IgA, IgM) levels in pleural effusions and serum.
• Comparison between metastatic effusions, non-metastatic effusions, and blood samples.

Main Results:

• Metastatic effusions had significantly higher immunoglobulin and total protein content than non-metastatic effusions.
• Serum immunoglobulin levels were higher in non-cancer patients compared to cancer patients.
• No significant difference in relative T- or B-cell content, but increased spontaneous lymphocyte proliferation in cancer effusions.
• Lower PHA-stimulated transformation index in cancer patient effusions.

Conclusions:

• Pleural effusions in cancer patients exhibit distinct immunological profiles, including elevated immunoglobulins and altered lymphocyte proliferation.
• Serum immunoglobulin levels may serve as a differentiating marker between cancer and non-cancer patients.
• The findings suggest impaired lymphocyte responsiveness in the pleural environment of cancer patients.