Abstract:
Objective
To study the serum levels of matrix metalloproteinase-9 (MMP-9) and its gene expression in peripheral blood mononuclear cells in children with Mycoplasma pneumoniae pneumonia(MPP), in order to provide a theoretical basis for the role of MMP in immune pathogenesis of Mycoplasma pneumoniae pneumonia in children.
Methods
Totally 78 cases of acute MMP patients treated and followed up in Department of Respiration of our hospital from January 2015 to August 2016 were selected as the observation group. Enzyme-linked immunosorbent assay(ELISA) and realtime quantitative PCR method were used to detect the level of serum MMP-9 in acute period and recovery period and the gene expression of MMP-9 in peripheral blood mononuclear cells; at the same time, a total of 78 healthy children in our hospital for health examination were selected as the control group and were given same testing.
Results
The level of MMP9 in the acute stage of the observation group was significantly higher than that in the recovery stage and that of the control group(P<0.05), but there was no difference between the recovery stage and control group(P>0.05). At the same time, positive expression of MMP-9 mRNA in children at acute rate was higher than that at the recovery period and that of the control group(P<0.05).
Conclusion
The level of serum MMP-9 and the positive rate of MMP-9 mRNA are of great significance for the diagnosis of the disease.

Key words: Mycoplasma pneumoniae pneumonia, Matrix metalloproteinase-9, Enzyme-linked immunosorbent assay, Immunity, Children