A new study published in the journal Respiratory Research revealed that an enzyme called matrix metalloproteinase 10 may be a suitable novel biomarker for idiopathic pulmonary fibrosis (IPF). The study was led by researchers at the Kyoto University in Japan and is entitled “Matrix metalloproteinase-10: a novel biomarker for idiopathic pulmonary fibrosis.”
IPF is a progressive fatal lung disease of unknown origin in which the alveoli and the lung tissue are damaged, becoming thick and scarred (fibrosis), leading to severe breathing difficulties, and compromising oxygen transfer between the lungs and the bloodstream. The disease is characterized by a shortness of breath that gradually worsens, with respiratory failure being the main cause of death. There is no cure for IPF, and it is estimated that almost 130,000 individuals in the United States and 5 million worldwide suffer from the disease. IPF has a poor prognosis and approximately two-thirds of the patients die within five years after being diagnosed.
Matrix metalloproteinases (MMPs) are enzymes capable of degrading matrix proteins and remodeling the extracellular matrix (ECM). MMPs have been suggested to be involved in IPF pathogenesis; in fact, MMP-7 has been described as a likely prognostic biomarker for the disease.
MMP-1, -2 and -7 have been found in higher levels in the blood of IPF patients, while MMP-3, -8 and -9 are present in elevated levels in the bronchoalveolar lavage fluid (BALF). The link between MMP-10 and IPF is, however, poorly elucidated.
In the study, researchers analyzed the expression of serum MMPs, including MMP-10, in 57 IPF patients, and assessed their possible link to disease severity, deterioration of pulmonary function, and survival. In 19 of the patients, MMP-7 and MMP-10 levels were also determined in the BALF.
Researchers found that serum levels of MMP-7 and MMP-10 significantly correlated with indicators of lung function (namely, predicted forced vital capacity and predicted diffusing capacity of the lung for carbon monoxide). The levels of both MMPs were also found to correlate between BALF and serum samples. Interestingly, serum MMP-10 was found to correlate more significantly with prognosis and disease severity in IPF patients in comparison to MMP-7. Furthermore, MMP-10 was the only one found to have prognostic value for clinical deterioration within six months and overall survival. In the lungs of IPF patients, a higher expression of MMP-10 was detected on macrophages, alveolar epithelial cells, and peripheral bronchiolar epithelial cells.
The research team concluded that MMP-10 may represent a new valuable biomarker for IPF in terms of disease severity and prognosis. Further studies with larger numbers of patients should be conducted to validate these findings, and to elucidate the role played by MMP-10 in IPF pathogenesis.