In vivo effects of PUVA on lymphocytes function

Area of Science:

• Immunology
• Photobiology
• Dermatology

Background:

• Psoralen-plus-ultraviolet-A (PUVA) therapy is a common photochemotherapy for various skin conditions.
• The effects of PUVA on circulating lymphocyte populations require further elucidation.

Purpose of the Study:

• To investigate the impact of whole-body erythemogenic and sub-erythemogenic doses of PUVA on lymphocyte subsets in normal volunteers.

Main Methods:

• Normal volunteers were exposed to whole-body PUVA.
• Circulating lymphocytes were analyzed for sheep erythrocyte rosette-forming (T-cells) and surface membrane immunoglobulin-positive (B-cells) cells, as well as null cells.
• Lymphocyte response to phytohaemagglutinin and absolute counts of lymphocytes and polymorphonuclear leukocytes were assessed.

Main Results:

• Erythemogenic PUVA doses decreased T-cells and B-cells and increased null cells.
• Sub-erythemogenic PUVA doses showed similar but less pronounced effects.
• These alterations were observed within 30 minutes, peaked at 12-16 hours, and normalized by 72 hours post-exposure.
• Lymphocyte response to phytohaemagglutinin and absolute counts of lymphocytes and neutrophils remained unchanged.

Conclusions:

• Whole-body PUVA therapy induces transient, dose-dependent changes in circulating lymphocyte subsets.
• The observed alterations in lymphocyte proportions do not impair lymphocyte function or alter absolute cell counts.