[Serum antibodies in urinary infection in children. Significance and relation to pyelonephritis]

Serum antibodies were measured repeatedly in 176 cases of urinary tract infections in children. The method used, passive haemagglutination with the bacterial antigen of the patient's urinary infection, gives a positive reading from 1/160. Antibodies were found in 139 cases and the lower limit compatible with a diagnosis of pyelonephritis was 1/2560. The result may, however, be negative in infants of less than one year. As in the first publication, the authors describe three types of curves of progression. Analysis confirms the relationship between persistent antibodies and evolutive pyelonephritis. Experimental results and a comparison of clinical and pathological findings are discussed and support the notion of the value of a persistent high antibody level in the diagnosis of chronic pyelonephritis.