A novel biomarker of type VII collagen degradation increases in patients with atopic dermatitis and decreases upon treatment with immunosuppressants.

Remodelling of the extracellular matrix (ECM) is a continuous process necessary for maintaining skin tissue architecture and function. Disruption of type VII and XVII collagen turnover within the ECM is a contributing factor in the pathogenesis of skin conditions such as atopic dermatitis (AD). To investigate the turnover of type VII and XVII collagens in AD using novel biomarkers of ECM turnover. Type VII (C7M) and XVII (PRO-C17) collagen turnover were measured using ELISAs. The cohort comprised 158 AD patients and 20 matched healthy donors (HD), with 53 of the AD patients treated with topical calcineurin inhibitors. Disease severity was assessed using the SCORAD index, categorizing patients into mild (SCORAD < 25), moderate (SCORAD: 25-50), and severe (SCORAD > 50) groups. AD patients across all severity groups had higher C7M levels (all: p < 0.0001), while the levels of PRO-C17 were higher in mild AD patients versus HD (p = 0.0399). The C7M marker demonstrated an AUC of 0.96, and its levels were decreased in AD patients undergoing topical calcineurin inhibitor treatment (p=0.0073). The turnover of type VII and XVII collagens, measured by the biomarkers C7M and PRO-C17, is elevated in patients with AD. The biomarker C7M may have the potential to serve as a diagnostic and treatment response biomarker in AD.