OBJECTIVE:Paraquat(PQ) poisoning-induced pulmonary fibrosis causes asphyxiation and death.The therapeutic potential of intravenous Xuebijing therapy in PQ poisoning patients and its underlying immunomodulatory effects on transforming growth factor(TGF)-β1 and procollagen type III peptide(PIIIP) were investigated.METHODS:Thirty-six acute PQ poisoning patients were randomly assigned to conventional therapy(Group A) and intravenous Xuebijing administration plus conventional therapy(Group B).Twenty volunteers served as controls(Group C).Blood samples were collected upon admission(day 0) and at post-treatment days 5,10,and 14.TGF-β1 and PIIIP concentrations were determined by ELISA and analyzed for intra-and inter-group differences over time.One-month follow-up was conducted for determining the mortality rate.RESULTS:TGF-β1 and PIIIP levels were significantly higher in PQ poisoning patients and increased over time(Groups A and B vs C,P