Serum dsDNA is environmentally contingent.

Psoriasis is a recurrent autoimmune disease characterized by seasonal and latitudinal variations. Double-stranded DNA (dsDNA) is a crucial component of nucleic acids and nucleosomes that provoke innate immune responses. Given the potential influence of climate on immunity and the development of autoimmune diseases, a comprehensive quantitative analysis of dsDNA levels in the population is warranted. In this case-control study conducted from 2016 to 2020, 10,110 psoriasis patients and matched controls from 12 regions in China were included. This study examined variations in serum dsDNA levels based on season and latitude. The results revealed significant associations between geographical location, climatic conditions, and season with serum dsDNA concentration. Individuals residing in Northern China exhibited significantly higher serum dsDNA levels compared to those in the South (1.00 vs. 0.96 ng/ml), and those in medium latitude regions had higher levels than their counterparts in areas with extreme latitudes (0.98 vs. 0.96 ng/ml). Furthermore, individuals in regions with low to medium ultraviolet exposure demonstrated higher serum dsDNA concentrations than those in areas with high ultraviolet levels (1.03 vs. 0.93 ng/ml), and individuals in winter showed higher levels than those in summer (1.03 vs. 0.92 ng/ml). Factors such as sex, UV index, humidity, and sunshine duration were inversely related to serum dsDNA levels, while age and daylight hours showed a positive association. These findings suggest that meteorological and climatic factors play a role in influencing serum dsDNA levels.