Lymphopenia and CD4+/CD8+ Cell Reduction under Fumaric Acid Esters

Area of Science:

• Immunology
• Dermatology
• Pharmacology

Background:

• Fumaric acid esters (FAEs) are a common treatment for moderate-to-severe plaque psoriasis.
• Previous studies indicated that FAEs can cause lymphopenia and reduce CD4+ and CD8+ cell counts in psoriasis patients.
• Opportunistic infections have been rarely reported in association with FAE-induced lymphopenia.

Purpose of the Study:

• To investigate the impact of FAEs on white blood cells, specifically leukocytes, lymphocytes, and CD4+/CD8+ T-cells, in patients undergoing psoriasis therapy.
• To prospectively analyze the changes in these cell counts during FAE treatment.

Main Methods:

• A cohort of 105 patients with moderate-to-severe chronic plaque psoriasis was observed in a single-center trial.
• T-cell subset analyses were conducted for a subset of 36 patients.
• Patient demographics including age and sex were recorded.

Main Results:

• The median lymphocyte count decreased by 35.8% within 6 months of FAE therapy.
• Lymphopenia (<1500/µL) was observed in 46.7% of patients, with severe lymphopenia (<500/µL) in 11.4%.
• Significant reductions were noted in CD4+ (30.2%) and CD8+ (45.3%) T-cell counts.

Conclusions:

• This study represents the largest prospective analysis of CD4+ and CD8+ cell counts in psoriasis patients treated with FAEs.
• Periodic monitoring of absolute lymphocyte counts is suggested during FAE therapy.
• Establishing baseline and follow-up T-cell subset determinations before and during treatment is recommended.