Serum circulating <i>S100A7</i> and <i>S100A15</i> DNA copies are elevated in patients with psoriasis and atopic dermatitis

In this study, we investigated whether circulating S100A7 and S100A15 DNA copies in cell-free DNA (cfDNA) are elevated in patients with psoriasis and atopic dermatitis (AD) and their levels are correlated with clinical findings. Serum cfDNA was obtained from 124 psoriasis patients and 45 AD patients. Circulating S100A7 and S100A15 DNA copies in psoriasis and AD patients were significantly higher than in healthy controls. Although circulating S100A7 and S100A15 DNA copies showed a significant positive correlation with the Psoriasis Severity and Area Index (PASI) scores in patients with severe psoriasis (PASI ≥ 10), in AD patients there was no significant correlation between their levels and disease severity. Furthermore, in psoriasis patients, circulating S100A15 DNA copies were significantly decreased in patients after treatment compared with patients before treatment.