Bacteriuria increases the risk of edematous attacks in hereditary angioedema with C1-inhibitor deficiency.

Urinary tract infections are considered among the most common infectious disorders in humans. Various infections may have a role in inducing HAE attacks. Our study intended to evaluate bacteriuria in the urinalysis of patients with C1-INH-HAE. Urine specimens contributed by 139 patients with C1-INH-HAE at the annual control visits were studied retrospectively for microorganisms. We analyzed the presence of bacteriuria in relation to the clinical symptoms. Taking into account three randomly selected urine specimens, we found that the cumulative number of edematous attacks was higher in patients with bacteriuria than in those without (P = 0.019, P = 0.022, P = 0.014). Considering the same patients, attack number was significantly higher (14.51 vs 8.63) in patients with bacteriuria than in those without (P < 0.0001). In patients with bacteriuria, we found a higher incidence of edema formation during the year before evaluation, which may suggest the triggering role of bacteriuria in the occurrence of edematous episodes.