title: Evaluation of antibody class in response to endoscopic subureteral collagen injection in patients with vesicoureteral reflux.
abstract: OBJECTIVE
  Clinical problems after glutaraldehyde cross-linked collagen injection for vesicoureteral reflux are the appearance of anticollagen antibodies and a decrease in collagen with time. We evaluated whether antibody production affects reflux recurrence and implanted collagen absorption.
  
  
  METHODS
  We treated 27 patients (39 ureters) who had vesicoureteral reflux with endoscopic subureteral glutaraldehyde cross-linked collagen injection. The maximum diameter of the elevated ureteral orifice was measured 3-dimensionally and the numerical value calculated by multiplying each diameter by approximately pi/6 was used as the ultrasound estimate of injected collagen volume. The 1-to-6-month collagen volume ratio was used as an index of the decrease in implant collagen volume. The antibody class against bovine collagen was characterized by indirect enzyme-linked immunosorbent assay.
  
  
  RESULTS
  Seroconversion in 6 patients was noted a mean 6.8 months after the first injection. In these patients the antibody class was IgG dominant and IgA or IgM was not detected. There was no significant difference in the total injected collagen volume, total number of injections or collagen volume ratio in the seropositive and seronegative groups. Reflux recurred in 4 patients and the curve of the reflux-free rate was similar regardless of antibody appearance.
  
  
  CONCLUSIONS
  The immune response to bovine collagen injection for vesicoureteral reflux does not depend on injected collagen volume or an increased number of treatments. Antibody production had no effects on absorption of the implanted collagen or reflux recurrence.
authors.affiliation: Department of Urology, Hiroshima University School of Medicine, Hiroshima, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Inoue
authors.forename: T
authors.initials: T
authors.lastname: Nakamoto
authors.forename: A
authors.initials: A
authors.lastname: Usui
authors.forename: T
authors.initials: T
authors.lastname: Usui
mesh_terms: D000328:Adult; D000906:Antibodies / Q000097:blood; D002648:Child; D003094:Collagen / Q000008:administration & dosage* / Q000276:immunology*; D003432:Cross-Linking Reagents / Q000008:administration & dosage*; D006801:Humans; D007267:Injections; D011446:Prospective Studies; D018666:Ureteroscopy; D014718:Vesico-Ureteral Reflux / Q000097:blood / Q000276:immunology* / Q000628:therapy*
chemical_list: D000906:Antibodies; D003432:Cross-Linking Reagents; C048470:glutaraldehyde-cross-linked collagen; D003094:Collagen