Mycoplasma pneumoniae in adult community-acquired pneumonia increases matrix metalloproteinase-9 serum level and induces its gene expression in peripheral blood mononuclear cells

Abstract

SummaryBackgroundThe objective of this study was to assess the concentration of metalloproteinase-2 (MMP-2) and metalloproteinase-9 (MMP-9) in peripheral circulation and their mRNA expression in peripheral blood mononuclear cells (PBMCs) in patients with CAP caused by M. pneumoniae.Material/MethodsWe prospectively analyzed MMPs in 40 hospitalized patients with M. pneumoniae CAP on admission, and in the convalescent phase. Twenty healthy men were used as controls. Quantitative real-time PCR and ELISA tests were used.ResultsMMP-9 mRNA expression in PBMCs was increased in the acute phase of illness compared to the control group as well as in convalescent phase in which case it was statistically significant (Mann-Whitney; p=0.028). The same was found for MMP-9 plasma levels (Mann-Whitney test; p<0.001; p=0.001). Circulating MMP-2 concentration in acute patients was significantly lower than in the control group and convalescent phase (Mann-Whitney test; p=0.012; p=0.001), while no MMP-2 mRNA expression was found in PBMCs. The plasma level of MMP-9 correlated with leukocyte count in peripheral circulation (r=0.67, p<0.001).ConclusionsWe conclude that M. pneumoniae in adult CAP induces activity of MMP-9 in peripheral blood circulation.

Elevated serum matrix metalloproteinase-2 and -9 and their correlationswith severity of disease in patients with community-acquired pneumonia

“…We performed a zymographic analysis to determine active and inactive MMPs in the serums of CAP patients and controls. Active forms of MMP-2 and MMP-9 were 13 and 17 times higher, respectively, in CAP patients than controls, making our findings consistent with the results of previous studies (6,23,24,(26)(27)(28).…”

“…However, only a few studies in the literature have investigated the role of MMPs in pneumonia pathogenesis (6,(22)(23)(24)(26)(27)(28). These have shown that patients with hospital-acquired pneumonia (HAP) have excessive MMP-8 and -9 concentrations in plasma and mini-BAL fluids compared to healthy controls (22)(23)(24).…”

“…These have shown that patients with hospital-acquired pneumonia (HAP) have excessive MMP-8 and -9 concentrations in plasma and mini-BAL fluids compared to healthy controls (22)(23)(24). Excessive serum MMP-9 levels and MMP-9 activities have also been reported in the few studies of patients with CAP (6,(26)(27)(28). We performed a zymographic analysis to determine active and inactive MMPs in the serums of CAP patients and controls.…”

“…Some bacteria, such as S. aureus, P. aeruginosa, and E. coli, may be associated with severe pulmonary damage and severe pneumonia (necrotizing pneumonia). However, only one study in the literature investigated MMP levels in relation to etiological microorganisms in CAP patients, showing that M. pneumoniae induces activity of MMP-9 in the patients' peripheral circulation (28). In patients with HAP, high-risk bacteria, such as S. aureus and P. aeruginosa, are related to increased concentrations and activities of pulmonary MMP (19).…”

Convergence in the Epidemiology and Pathogenesis of COPD and Pneumonia

“…A number of studies have examined a possible relationship between MMP-9 and COPD. Plasma levels of MMP-9 have been reported to be increased in α 1 -antitrypsin deficiency-associated emphysema and in COPD, and to correlate negatively with FEV 1 (109,110). Increased plasma levels of MMP-9 have been shown to negatively correlate with FEV 1 and indicate a decline in pulmonary function (111).…”