The antibody response in chronic pyelonephritis.

Serum antibodies specific for the bacteria isolated from the urines of 41 patients with chronic pyelonephritis and 14 with asymptomatic bacteriuria were assayed. Even though it is clear that infections which involve the kidney evoke higher antibody responses than do purely bladder infections, it is difficult to establish a cut-off level for distinguishing the two by this method. There is a greater probability that there will be an upper urinary tract infection without an antibody response than that there will be a good antibody response in cases with lower tract infections. In our case list, 49% of the patients with chronic pyelonephritis had titers equal to or greater than 1:400, and another 44% had titers between 1:50 and 1:100. Therefore it appears that the magnitude of the antibody response depends not only on the location of the infection but also on other factors, such as the intrinsic immunogenicity of the different bacterial strains and the properties of the immunological system of the patient.