Extracellular matrix remodeling in children with airway foreign-body aspiration.
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.
Tang
Lan Fang
LF
Department of Respiratory Medicine, Zhejiang University Children's Hospital, School of Medicine, Zhugan Xiang, Hangzhou, China.
Du
Li Zhong
LZ
Chen
Zhi Min
ZM
Zou
Chao Chun
CC
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
D019715:Tissue Inhibitor of Metalloproteinase-1; D020780:Matrix Metalloproteinase 9; D006909:Hydroxyproline