Exhaled breath condensate of children with asthma contains higher levels of matrix metalloprotease-9 than in children who do not have the disease, researchers found in a Turkish study.
Researchers conducted a study of 42 children with asthma, aged 8 to 15 years, to test the matrix metalloprotease-9 (MMP-9) and natural tissue inhibitors of metalloproteinases (TIMP-1) levels of exhaled breath condensate (EBC). Investigators also evaluated asthma severity and whether the MMP-9 and TIMP-1 enzymes were related to interleukin (IL)-4/10 levels in EBC.
The study was divided into three cohorts: persistent asthma (n=20), intermittent asthma (n=10) and nonasthmatic controls (n=12). Each participant was evaluated for forced expiratory volume in 1 second (FEV1), peak expiratory flow and forced expiratory flow. Their MMP-9, TIMP-1 and IL-4/10 levels in EBC were then tested using ELISA assay.
The persistent asthma group had the highest levels of MMP-9 in EBC (57.7±17.5 ng/mL) compared with the intermittent asthma group (35.4±11.7 ng/mL) and the control group (30.6±3.7 ng/mL). Overall, the MMP-9 in EBC levels in the persistent and intermittent asthma groups were significantly higher than the control group’s (P<.001 and P=.047, respectively).
There was no statistically significant difference in TIMP-1 in EBC levels among the three groups.
In children with asthma, the results showed a positive correlation between levels of MMP-9 and IL-4/10 in EBC (r=0.419; P=.027 and r=0.405; P=.032; respectively).
“ … MMP-9 levels of EBC are elevated in children with asthma and correlated with lung functions and other inflammatory markers,” researchers wrote. “We suggest that EBC MMP-9 levels could be helpful in determining the severity of the disease.”
Disclosure: The researchers report no relevant financial disclosures.