Urinary tract infection in infants - Studies on management and genetic susceptibility

Abstract

Urinary tract infection (UTI) in infants is associated with kidney damage. Recommendations on investigations to identify patients at risk of recurrent UTIs and kidney related morbidity vary considerably. The objectives of this thesis were to evaluate current management of infants with their first UTI, including adherence to the Swedish UTI guidelines, and to investigate predictive clinical and genetic markers of UTI associated kidney damage. Infants <1 year presenting with a first episode of UTI were included in a nationwide prospective study with one year follow-up. Patient characteristics, laboratory results and findings on imaging of the kidneys and urinary tract were described (Paper I). Performed investigations were related to guideline recommendations for adherence studies (Paper II). In a subgroup, blood sample DNA was used for genetic association analysis of permanent kidney damage identified by renal scintigraphy (Paper III). Anatomical abnormalities and kidney damage were identified in line with previous prevalence estimates at the expense of a high number of investigations. Diagnostic work-up and treatment were largely performed according to guidelines while adherence to recommended imaging was lower. A genetic profile could segregate infants with permanent kidney damage from those without persistent damage. In conclusion, diagnostic and therapeutic management of infants with UTI is satisfying but the burden of radiation from imaging is high in relation to findings. A genetic susceptibility partly explains why some infants with kidney infection have persistent kidney defects while others heal without damage.