Antibody-coated bacteria in the urine of children with urinary tract infections.

The test for antibody-coated bacteria in urine for the diagnosis of the anatomical level of urinary tract infections was evaluated in children with UTI. The ability of the test to differentiate between an upper and lower infection is influenced by the antiglobulin preparation used, since too sensitive an antiglobulin probably detects nonspecifically bound antibodies. Staphylococcal protein A seems to be well suited for use as an antiglobulin in this test. Using staphylococcal protein A all children with X-ray findings suggesting renal damage had antibody-coated bacteria in the urine, however, nine infants and 5 children and clinical symptoms of pyelonephritis had a negative test. Of 28 children with clinical symptoms of cystitis only one had a positive test. Of 50 children with asymptomatic bacteriuria 9 had antibody-coated bacteria in the urine; 41 had not. The findings indicate that the method might be useful in establishing the anatomical level of urinary tract infection and might also be useful for screening children with asymptomatic bacteriuria who risk developing kidney infections.