lipid-a and Bacteriuria

Serum levels of antibodies to lipid A were determined with an enzyme-linked immunosorbent assay in 26 girls with their first known symptomatic urinary tract infection (UTI) and in 15 girls with asymptomatic bacteriuria (ABU). Also included were six female patients with recurrence of acute upper UTI, five of whom had renal changes after the infections; 28 female patients with renal scarring but not symptomatic UTI at the time of investigation; and uninfected individuals. IgG and IgM antibodies to lipid A were found in approximately 50% of the uninfected children older than two years of age. Girls with acute cystitis, acute pyelonephritis, or ABU showed significantly elevated levels of IgG antibodies to lipid A as compared with children with no history of UTI. High levels of IgG antibodies to lipid A may be indicative of severe renal infection and development or progression of renal parenchymal reduction. The diagnostic value of determining levels of antibodies to lipid A is discussed.

Topics: Adolescent; Bacteriuria; Child; Child, Preschool; Cystitis; Enzyme-Linked Immunosorbent Assay; Female; Humans; Immunoglobulin G; Immunoglobulin M; Infant; Lipid A; Lipopolysaccharides; Pyelonephritis; Urinary Tract Infections

Lipid A injected into the temporarily occluded renal pelvis of adult dogs, persisted in the kidney tissue and induced an abacterial interstitial nephritis with positive anti-lipid A titers. This reaction was increased by a single dose of lipid A vaccine, reduced by four consecutive immunisations prior to the lipid A injection and absent in puppies. The presence of IgG, IgM and complement complexes in the kidney was demonstrated by immunofluoroscopy. Lipid A antibody titers were measured by the passive hemolysis test in 349 humans. In two out of 20 healthy adults and 16 out of 18 children with recurrent urinary tract infection anti-lipid A antibodies were present. In contrast, no titers were found in 23 newborn babies. In a group of 156 patients with acute urinary tract infection, 28% revealed positive titers, whereas in a group of 132 patients with recurrent urinary tract infection titers occurred in 81%. Selected from this group of 132 patients 61 suffered from an acute infection of the upper tract. 59 oft these (96%) showed definite titers. There was no difference in the development of anti-lipid A antibodies between men and women and the height of the titers did not correlate with the clinical picture of the disease (acute or chronic). The combination of proteinuria and anti-lipid A antibodies indicates the pressure of reccurrent urinary tract infection or chronic pyelonephritis with about 90% accuracy. The titers are caused by immunogenically active lipid A in the body. Since lipid A has the ability to remain in the renal tissue for a long period of time and thereby to maintain the inflammatory response, long-term antimicrobial prophylaxis (six months) should be given to patients with a high risk of recurrent urinary tract infection.

Topics: Animals; Anti-Bacterial Agents; Antibodies; Bacteriuria; Dogs; Fluorescent Antibody Technique; Immunoglobulin G; Immunoglobulin M; Kidney Pelvis; Lipid A; Lipopolysaccharides; Pyelonephritis