title: Mycoplasma pneumoniae in adult community-acquired pneumonia increases matrix metalloproteinase-9 serum level and induces its gene expression in peripheral blood mononuclear cells.
abstract: BACKGROUND
  The 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.
  
  
  METHODS
  We 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.
  
  
  RESULTS
  MMP-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).
  
  
  CONCLUSIONS
  We conclude that M. pneumoniae in adult CAP induces activity of MMP-9 in peripheral blood circulation.
authors: University of Zagreb School of Medicine, University Hospital for Infectious Diseases, Dr. Fran Mihaljević, Zagreb, Croatia. ipuljiz@bfm.hr
authors: Ivan
authors: I
authors: Puljiz
authors: Alemka
authors: A
authors: Markotić
authors: Lidija
authors: L
authors: Cvetko Krajinovic
authors: Marija
authors: M
authors: Gužvinec
authors: Ozren
authors: O
authors: Polašek
authors: Ilija
authors: I
authors: Kuzman
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D017714:Community-Acquired Infections / Q000201:enzymology / Q000453:epidemiology / Q000235:genetics / Q000382:microbiology*; D017523:Croatia / Q000453:epidemiology; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000201:enzymology*; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000097:blood / Q000235:genetics; D020780:Matrix Metalloproteinase 9 / Q000097:blood* / Q000235:genetics*; D008875:Middle Aged; D009177:Mycoplasma pneumoniae / Q000502:physiology*; D011019:Pneumonia, Mycoplasma / Q000201:enzymology / Q000453:epidemiology / Q000235:genetics / Q000382:microbiology*; D018709:Statistics, Nonparametric; D055815:Young Adult
chemical_list: C522361:MMP2 protein, human; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9