Antibodies in Escherichia coli urinary tract infection

In 105 adults with E.Coli urinary tract infections, IgG coated bacteriuria was found in 8/9 with acute pyelonephritis (PN), 17/20 with chronic PN, and in only 2/76 with lower UTI. IgA was present in 66% of PN, but IgA secretory piece in less than 10%. These urinary IgG antibodies were, at least in part, synthesised in the kidney because serum IgG antibodies were detected by indirect immunofluorescence in only half the patients. 06, 018, 022 E.Coli serotypes were the three most frequently found O groups, but their prevalence in PN is not significant. The immunology of urinary tract infection (UTI) is still a subject of little interest in adult nephrology; but antibody production is a well-characterised event in pyelonephritis (PN), the study of which seems to be the best indirect procedure for localising the site of UTI. We have analysed the production of urinary and humoral antibodies, and their correlation with E.Coli serotypes in patients with E.Coli UTI.