title: Extracellular matrix remodeling in children with airway foreign-body aspiration.
abstract: The purpose of this study was to observe extracellular matrix remodeling in children with airway foreign-body aspiration (FBA) by detecting the expression of matrix metalloproteinase-9 (MMP-9), tissue inhibitor of matrix metalloproteinase-1 (TIMP-1), and hydroxyproline (HYP) in bronchoalveolar lavage fluid (BALF). Forty-six children with FBA and 12 control subjects from 2002-2003 were enrolled in this study. The former were divided into three subgroups according to duration of foreign-body (FB) retention (subgroup 1, <7 days; subgroup 2, 7-30 days; subgroup 3, >30 days). Cell count, and levels of MMP-9, TIMP-1, and HYP in BALF were measured. The total number of cells and differential counts detected in BALF did not differ significantly between patients and controls (P > 0.05), while mast cells were found only in the BALF of patients. The positive rates of MMP-9 in controls, subgroup 1, subgroup 2, and subgroup 3 were 33.3%, 62.5%, 80.0%, and 93.3%, respectively, with a significant difference (P = 0.006). The positive rate of TIMP-1 in controls and subgroups 1, 2, and 3 were 33.3%, 62.5%, 80.0%, and 93.3%, respectively, with a significant difference (P < 0.001) as well. HYP levels in subgroups 2 and 3 were significantly more increased than in subgroup 1 and controls (all P < 0.001). Levels of MMP-9, TIMP-1, and HYP in patients were positively correlated with duration of FB retention (all P < 0.05), and levels of MMP-9 and TIMP-1 were also positively correlated with percentage of mast cells in BALF (all P < 0.05). The differences in MMP-9 and TIMP-1 before and after FB removed were not significant (P > 0.05), while HYP levels decreased significantly after FB were removed (P = 0.001). Our findings support the hypothesis that FBA may contribute not only to mechanical airway obstruction, but also possibly to eventual airway remodeling by generation of MMPs and TIMPs.
authors.affiliation: Department of Respiratory Medicine, Zhejiang University Children's Hospital, School of Medicine, Zhugan Xiang, Hangzhou, China.
authors.forename: Lan Fang
authors.initials: LF
authors.lastname: Tang
authors.forename: Li Zhong
authors.initials: LZ
authors.lastname: Du
authors.forename: Zhi Min
authors.initials: ZM
authors.lastname: Chen
authors.forename: Chao Chun
authors.initials: CC
authors.lastname: Zou
mesh_terms: D000402:Airway Obstruction / Q000209:etiology / Q000473:pathology*; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry / Q000166:cytology; D001999:Bronchoscopy; D016022:Case-Control Studies; D002675:Child, Preschool; D005109:Extracellular Matrix / Q000201:enzymology / Q000473:pathology*; D005260:Female; D005547:Foreign Bodies / Q000150:complications / Q000473:pathology*; D006801:Humans; D006909:Hydroxyproline / Q000032:analysis; D007150:Immunohistochemistry; D007223:Infant; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000032:analysis; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000032:analysis; D014132:Trachea
chemical_list: D019715:Tissue Inhibitor of Metalloproteinase-1; D020780:Matrix Metalloproteinase 9; D006909:Hydroxyproline