Matrix metalloproteinases are associated with severity of disease among COVID-19 patients: A possible pharmacological target

COVID-19 is a devastating disease and imbalanced matrix metalloproteinase (MMP) activity may contribute to its pathophysiology. This exploratory study examined whether increased circulating concentrations of MMP-2 and MMP-9, and their endogenous inhibitors, the tissue inhibitors of MMP (TIMP)-1, TIMP-2, TIMP-3 and TIMP-4 are persistently found in patients 2 weeks after their recovery from severe or critical COVID-19 as compared with those in healthy controls. Subjects who had severe (n = 26) or critical (n = 25) PCR-confirmed COVID-19 and healthy controls (n = 21) had blood samples drawn 2 weeks after recovery and serum MMP-2, MMP-9, TIMP-1, TIMP-2, TIMP-3 and TIMP-4 were determined using two Human Luminex® Discovery Assays. Circulating MMP activity was also determined by gel zymography. Patients who had severe or critical COVID-19 had increased circulating MMP-9 and MMP-2 concentrations, with increased MMP-9/TIMP-1 and MMP-2/TIMP-2 ratios indicating increased MMP activity, confirmed by gel zymography (all p < 0.05). Higher circulating MMP-9 (but not MMP-2) concentrations were found in critical versus severe COVID-19 (p < 0.05). We found increased circulating MMP-9 and MMP-2 concentrations and activity many days after recovery from the acute disease, with MMP-9 levels associated with disease severity. These biochemical alterations suggest that MMP-2 and MMP-9 may be important pharmacological targets in COVID-19.