Role of MMP-9, TIMP-1 as Markers of Lung Imaging and Functional Abnormality of COVID-19

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV2), which has different degrees of severity, is the cause of Coronavirus Disease 2019 (COVID-19). Over 97% of COVID-19 patients make a full recovery. Inflammation increases when COVID-19 severity increases. The lungs and endothelium will suffer harm when different pro-inflammatory cytokines are released. A cytokine storm is started when many immune cells produce cytokines and chemokines. The pro-inflammatory cytokine can increase angiogenesis, vascular permeability, keratin proliferation, and collagen production. Lung lesions are affected by certain disorders. In COVID-19 patients, angiogenesis, fibroblast activation, and collagen deposition all contribute to the repair of the lungs. The pathological outcome of acute or chronic interstitial pulmonary disease is lung fibrosis, characterized by abnormal collagen and extracellular matrix (ECM) deposition, the persistence of fibroblasts, failure of alveolar re-epithelization, and destruction of normal pulmonary architecture. The breakdown or buildup of ECM is influenced by the ratio of matrix metalloproteinase (MMP) and tissue inhibitor matrix metalloproteinase (TIMP). TIMP distribution, not MMP distribution, was the primary contributor to lung fibrosis. MMP expression is increased by the production of several hormones, cytokines (IL-1, IL-6), growth factors (TGF, TNF-), platelet-derived growth factor (PDGF), and basic fibroblast growth factor (bFGF).

ECM assistance is required for the alveoli to function normally. Excessive ECM breakdown and aberrant ECM remodelling are the root causes of many respiratory conditions, including pulmonary fibrosis. ECM buildup destroys the alveolar process, particularly by impairing alveolar-capillary diffusion. On radiological images, lung abnormalities can be seen as pneumonia in the bilateral ground-glass opacity basal, which results in hypoxia. In the lower portion, bilateral abnormalities predominated. COVID-19 ARDS, hypoxemia, bilateral infiltrates, and reduced lung compliance were the hallmarks of pneumonia type H. Despite the limited sensitivity, plain chest X-rays can detect lung abnormalities in COVID-19; they are inexpensive and simple. New infiltrates on chest radiographs were used to make the diagnosis of pneumonia.

Biomarkers of pulmonary interstitial abnormalities have received limited attention in the literature, including investigations on MMP and TIMP for lung abnormalities in COVID-19 patients. One of the MMP gelatinase family's more complicated forms, MMP-9, can break down ECM components. MMP-9 increases collagen and cytokine production, fibroblast migration, and TGF- stimulation. MMP-9 is among the MMPs that TIMP1 effectively inhibits. TIMP-1 binds to pro- or latent MMP-9. For ECM proteolysis to occur, MMP and TIMP must coexist in equilibrium. This study aimed to ascertain how MMP-9 and TIMP-1 affected abnormal chest X-rays, poor oxygenation, severity, and death.

Blood is taken from hospitalized COVID-19 patients to measure the serum concentrations of MMP-9 and TIMP-1. At the time of hospital admission, three reviewers assessed the severity after chest X-Rays, followed by a BRIXIA score. At the time of hospital discharge, patients were evaluated. The levels of MMP-9 and TIMP-1 were compared to Brixia scores, oxygen consumption, severity, and death.