Amphotericin B and 5-fluorocytosine: in vitro effects on lymphocyte function

Area of Science:

• Immunology
• Pharmacology
• Infectious Diseases

Background:

• Antifungal agents like amphotericin B and 5-fluorocytosine are crucial for treating serious fungal infections.
• Understanding their impact on the host immune system is vital for optimizing treatment strategies and predicting outcomes.

Purpose of the Study:

• To investigate the in vitro effects of amphotericin B and 5-fluorocytosine, individually and in combination, on key lymphocyte functions.
• To assess the impact of these antifungals on lymphocyte proliferation, T-cell receptor interactions, and B-cell surface markers.

Main Methods:

• Lymphocyte cultures were exposed to amphotericin B, 5-fluorocytosine, or both agents.
• Lymphocyte transformation assays were performed using spontaneous, antigen (streptokinase-streptodornase), and mitogen (phytohemagglutinin, concanavalin A) stimulation.
• Flow cytometry was used to analyze T-lymphocyte receptors for sheep erythrocytes and B-lymphocyte surface immunoglobulin and complement receptors.

Main Results:

• Amphotericin B significantly suppressed spontaneous lymphocyte transformation and responses to streptokinase-streptodornase.
• The combination of amphotericin B and 5-fluorocytosine also suppressed these lymphocyte responses.
• Neither drug, alone or combined, affected lymphocyte responses to phytohemagglutinin or concanavalin A.
• No changes were observed in T-lymphocyte sheep erythrocyte receptors or B-lymphocyte surface immunoglobulin and complement receptors.

Conclusions:

• Amphotericin B exhibits immunosuppressive effects on specific lymphocyte functions in vitro, particularly antigen-specific responses.
• 5-Fluorocytosine alone does not appear to significantly alter lymphocyte function in this in vitro model.
• The combination therapy's impact on lymphocyte function warrants further investigation, especially concerning potential clinical implications for immune competence during treatment.