RESOLUTION TIME OF ESCHERICHIA-COLI CYSTITIS IS CORRELATED WITH LEVELS OF PREINFECTION ANTIBODY TO THE INFECTING ESCHERICHIA-COLI STRAIN

Objectives. A number of studies in animals have demonstrated that immu nization against uropathogenic bacteria can lessen the severity or dur ation of induced urinary tract infections (UTI). This study examined w hether preinfection levels of serum or urinary anti-Escherichia coli a ntibodies were correlated with length of time needed to resolve an ind uced E coli cystitis. Methods. Serum and urine anti-E coli antibody le vels in 36 control and 42 vaginally immunized cynomolgus monkeys were measured by enzyme-linked immunosorbent assay. Regression analyses wer e used to determine correlations between resolution time and preinfect ion antibody level, and to estimate antibody levels that might be asso ciated with effective resolution of an E coli UTI. Results. Linear reg ression analysis showed significant correlations between short resolut ion time and high levels of serum immunoglobulin M (IgM), urinary secr etory IgA, and urinary Ige specific for the infecting E coli strain. S erum IgM and urinary IgG anti-E coli levels in monkeys that cleared in fections early were significantly higher than in animals with protract ed infections. Logistic regression estimated the serum IgM and urinary Ige anti-E coli levels associated with a 50% probability of accelerat ed clearance to be 3.3 mu g/mL and 2.7 mu g/24 hours, respectively. Co nclusions. For this primate model, the observed correlations between s hort resolution time and pre-existing serum and urinary antibody sugge st that antibody-mediated immunity is an important component of host d efense against UTI.