title: Estrogenic action on innate defense mechanisms in the urinary tract.
abstract: Clinical data suggest an impact of estrogen on the pathogenesis of urinary tract infections (UTI). In particular, women after menopause often suffer from recurrent UTI, characterized by at least three acute UTI episodes within a year. Aside from bacterial factors promoting persistence within the urinary bladder, the low estrogen levels induce structural and chemical changes in the urogenital tract which facilitate UTI. Increased residual urine volume and changes in the vaginal microflora are well documented risk factors. Local supplementation with estrogen can at least partly reverse these changes. Treatment allows the re-establishment of a lactobacilli-dominated vaginal microflora and improves epithelial differentiation and integrity in the urogenital tract. This estrogenic effect on the epithelium is marked by an increased production of antimicrobial peptides and a tighter intercellular connection, preventing bacteria from reaching cells where they can hide and later emerge and cause a new infection. Estrogen in the dosages and applications used to date is considered safe for the endometrium in the majority of women. Based on the actions and safety of estrogen, local supplementation thus offers a treatment option for postmenopausal women suffering from recurrent UTI.
authors.affiliation: Department of Microbiology, Tumor and Cell Biology, Division of Clinical Microbiology, Karolinska Institutet and Karolinska University Hospital, 17176 Stockholm, Sweden.
authors.forename: Petra
authors.initials: P
authors.lastname: Lüthje
authors.affiliation: Department of Women's and Children's Health, Division of Obstetrics and Gynecology, Karolinska University Hospital and Karolinska Institutet, 17177 Stockholm, Sweden.
authors.forename: Angelica Lindén
authors.initials: AL
authors.lastname: Hirschberg
authors.affiliation: Department of Microbiology, Tumor and Cell Biology, Division of Clinical Microbiology, Karolinska Institutet and Karolinska University Hospital, 17176 Stockholm, Sweden. Electronic address: Annelie.Brauner@ki.se.
authors.forename: Annelie
authors.initials: A
authors.lastname: Brauner
mesh_terms: D004967:Estrogens / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D064307:Microbiota / Q000187:drug effects*; D001743:Urinary Bladder / Q000187:drug effects / Q000382:microbiology; D014552:Urinary Tract Infections / Q000382:microbiology / Q000517:prevention & control*; D019459:Urothelium / Q000187:drug effects* / Q000382:microbiology; D014621:Vagina / Q000187:drug effects / Q000382:microbiology
chemical_list: D004967:Estrogens
keywords: Antimicrobial peptides; Epithelial differentiation; Estrogen supplementation; Innate immunity; Recurrent urinary tract infection; Uropathogenic Escherichia coli