alpha-chymotrypsin and Gastroenteritis

Human noroviruses (HuNoVs) are the leading cause of acute gastroenteritis worldwide. Histo-Blood Groups Antigens (HBGAs) have been described as attachment factors, promoting HuNoV infection. However, their role has not yet been elucidated. This study aims to evaluate the ability of HBGAs to protect HuNoVs against various factors naturally found in the human digestive system. The effects of acid pH and proteolytic enzymes (pepsin, trypsin, and chymotrypsin) on GII.4 virus-like particles (VLPs) and GII.4 HuNoVs were studied, both during interactions and non-interaction with HBGAs. The results showed that GII.4 VLPs and GII.4 HuNoVs behaved differently following the treatments. GII.4 VLPs were disrupted at a pH of less than 2.0 and in the presence of proteolytic enzymes (1,500 units/mL pepsin, 100 mg/mL trypsin, and 100 mg/mL chymotrypsin). VLPs were also partially damaged by lower concentrations of trypsin and chymotrypsin (0.1 mg/mL). Conversely, the capsids of GII.4 HuNoVs were not compromised by such treatments, since their genomes were not accessible to RNase. HBGAs were found to offer GII.4 VLPs no protection against an acid pH or proteolytic enzymes.

Topics: Blood Group Antigens; Caliciviridae Infections; Capsid; Chymotrypsin; Dose-Response Relationship, Drug; Gastroenteritis; Humans; Hydrogen-Ion Concentration; Norovirus; Pepsin A; Peptide Hydrolases; Trypsin; Virus Attachment

Random fecal chymotrypsin activity and fecal alpha 1-antitrypsin (FA-1-AT) concentrations were determined in 11 children with cystic fibrosis, 5 children with Crohn's disease, 9 children with chronic aspecific diarrhea, 85 children with acute gastroenteritis, and 54 control children. Cystic fibrosis patients showed only very low fecal chymotrypsin values that did not overlap with values obtained in patients with either acute or chronic diarrhea. When compared with our control group, a significant increase of FA-1-AT concentrations was found only in children with Crohn's disease. Normal values were found in all patients with either chronic aspecific diarrhea or cystic fibrosis, while 12 of 85 children with acute gastroenteritis showed FA-1-AT concentrations above the 95th percentile of control children. We conclude that diarrhea (either acute or chronic) does not significantly decrease the clinical usefulness of fecal chymotrypsin activity measurements in the diagnosis of pancreatic insufficiency, while acute (gastroenteritis) but not chronic (chronic aspecific diarrhea, cystic fibrosis) diarrhea can give rise to protein losing and FA-1-AT concentrations similar to those found in Crohn's disease.

Topics: Adolescent; alpha 1-Antitrypsin; Child; Child, Preschool; Chymotrypsin; Crohn Disease; Cystic Fibrosis; Diarrhea; Feces; Female; Gastroenteritis; Humans; Male

Topics: Animals; Chymotrypsin; Clinical Enzyme Tests; Dog Diseases; Dogs; Feces; Female; Gastroenteritis; Male; Pancreatic Diseases; Trypsin