An Integrated Model of Alopecia Areata Biomarkers Highlights Both Th1/Th2 Upregulation, with Stronger Correlations Between Th2 Activation and Disease Severity

The study investigated biomarkers in alopecia areata (AA) and their relationship with disease severity by analyzing serum cytokines and cytokine expression in scalp tissue from 30 AA patients compared to 10 controls. Elevated levels of T-cell, Th1/IFN, and Th2 markers were found in AA patients' serum, with T-cell activation and Th2 markers showing significant correlation with clinical severity based on the Severity of Alopecia Tool (SALT). Serum Th2 markers also correlated with mRNA expressions in nonlesional scalp. Scalp mRNA of Th2 markers and IL-12/23p40 were positively correlated with AA severity, while hair keratins showed a negative correlation. The findings suggest AA is a systemic disease with immune activation in nonlesional skin and that Th1 and Th2 upregulation are linked to AA, particularly Th2 in relation to disease severity.