Abstract:

Objective To explore the diagnostic value of matrix metalloproteinase 9 (MMP9) and its related proteins for food allergy (FA) in infants. Methods This nested case-control study enrolled infants with suspected FA from April to October 2023. Infant feces were collected and the infants were divided into FA group and non-FA group according to the results of oral food challenges. The fecal MMP9, tissue inhibitor of metalloproteinase 1(TIMP1) and lipocalin 2(LCN2) were measured by enzyme-linked immunosorbent assay, and the relative content was calculated. The area under the ROC curve (AUC), sensitivity and specificity were used to evaluate the accuracy of the target proteins in the diagnosis of infantile FA. We assessed the diagnose value by area under the curve (AUC), sensitivity and specificity. The predictors of FA were screened by binary logistic regression analysis. Results A total of 69 patients in the FA group and 72 patients in the non-FA group were included. The AUC values of fecal MMP9 and TIMP1 concentrations for the diagnosis of FA were 0.82 and 0.78, respectively, and the AUC values of the relative contents of MMP9 and TIMP1 were increased to 0.85 and 0.83, respectively. The diagnostic value of LCN2 is poor. Binary multivariate logistic regression analysis suggested that fecal MMP9 was the best predictor of FA. Conclusion Fecal MMP9 and TIMP1 are useful diagnostic tools for FA in infants, and can distinguish FA from other similar diseases.

Key words: food allergy, matrix metalloproteinase 9, lipocalin 2, tissue inhibitor of metalloproteinase 1, infant