Background Elevated concentrations of matrix metalloproteinases (MMP) have been associated with neonatal morbidity. There are no data on the serum levels of MMP-2, MMP-9, tissue inhibitors of matrix metalloproteinase (TIMP-1) from preterm infants recovering from these morbidities. We aimed to compare MMP-2, MMP-9, and TIMP-1 levels in preterm and term infants hospitalized with their first episode of wheezing.

Methods We prospectively evaluated 18 preterm infants with a history of chronic lung disease, respiratory distress syndrome and 14 age- and sex- matched term infants who were admitted for a first episode of wheezing. We quantified total serum concentrations of MMP-2, MMP-9, and TIMP-1 to assess whether these serum markers levels were associated with wheezing with a history of oxygen therapy during the neonatal period.

Results Upon hospitalization for the first episode of wheezing, MMP-2 and TIMP-1 levels were higher in preterm infants than in term infants.

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[Comparison of MMP-2, MMP-9, and TIMP-1 levels]

In contrast, there was no significant relationship between MMP-9 levels or the MMP-9/TIMP-1 ratio between preterm and term infants (univariate analysis). The area under the ROC curve for MMP-2 was 0.70 (95% CI 0.51–0.89, p=0.04). The area under the curve for TIMP-1 was 0.78 (95% CI 0.61–0.94, p=0.007). MMP-9, MMP-2, and TIMP-1 levels did not correlate with gestational age, gender, severity of wheezing.

Conclusion Elevated serum MMP-2 and TIMP-1 levels appear to increase the risk for wheezing. Further studies will be required to determine whether therapeutic inhibitors will prevent recurrent lung morbidities in preterm infants.