ABSTRACT
BACKGROUND: The pathogenesis of infantile hypertrophic pyloric stenosis (IHPS) is not fully understood. Hypertrophy of the pyloric muscle is probably regulated by growth factors. Recent studies reported an increase in the local synthesis of insulin-like growth factor-1 (IGF-1). There are no reports concerning platelet-derived endothelial cell growth factor (PDEGF) playing an important role in the pathological angiogenesis. The aim of this study was to analyze the expressions of IGF-1 and PDEGF by immunohistochemistry (IHC) in the muscularis propria of the pyloric muscle in children with IHPS. MATERIAL/METHODS: Twenty-two muscle biopsies were obtained at the time of pyloromyotomy. The control group consisted of seven children. Specimens were evaluated by routine histopathological methods and by immunohistochemistry using monoclonal mouse anti-PDEGF or -IGF-1 antibodies. Cells showing positive reaction were counted in five random 200x high-power fields. Values were expressed as the mean +/-SD of the real expression area of the analyzed marker to the total analyzed area. RESULTS: In children with IHPS the average area of PDEGF expression was 62+/-52.5, whereas in the control group it was 15+/-12.1. The average area of IGF-1 expression was 1037+/-491.9) in study group and 259+/-221.44 in the controls. Statistically significant differences were found. CONCLUSIONS: These results show a local increase in the expressions of IGF-1 and PDEGF in the muscularis propria of the pyloric muscle in children with IHPS, which may have implications to the pathogenesis of the disease.
