Matrix metalloproteinase-7 could be a predictor for acute inflammation in psoriatic patients

Purpose: The pathogenesis of psoriasis is characterized by a disruption of extracellular matrix (ECM) in which matrix metalloproteinases (MMPs) participate actively. We aimed to determine MMP-7 level and its association with the inflammatory response in order to determine its usefulness as a biomarker for psoriasis prediction. We also aimed to determine its distribution in uninvolved and involved psoriatic skin to evaluate the probable role of MMP-7 in psoriasis pathogenesis.

Materials and methods: We recruited 108 psoriatic patients and 133 healthy controls. MMP-7, tissue inhibitors of metalloproteinases (TIMPs) and interleukin-6 (IL-6) levels were measured by Enzyme-Linked Immunosorbent Assay (ELISA) assay. MMP-7 expression was detected by Immunohistochemistry (IHC) study.

Results: ECM turnover and inflammatory biomarker levels were significantly higher in psoriatic patients. MMP-7 revealed to be independently associated to psoriasis even after adjustment for different models. The area under the curve (AUC) of MMP-7 and inflammation Z-score were similar. MMP-7 was positively correlated with IL-6 and inflammation Z-score. Psoriasis severity (PASI) was correlated significantly with IL-6 (p = 0.007). The MMP-7 expression was detected in the epidermis of involved and uninvolved psoriatic skin. In involved skin, MMP-7 was expressed by basal and mostly suprabasal keratinocytes. In uninvolved skin, expression of MMP-7 was restricted to basal keratinocytes.

Conclusion: MMP-7 is independently associated to psoriasis disease and to inflammatory response which make it a potential biomarker for this dermatosis.