title: Acute focal bacterial nephritis in a cohort of hospitalized adult patients with acute pyelonephritis. Assessment of risk factors and a predictive model.
abstract: BACKGROUND
  Acute focal bacterial nephritis (AFBN) is a complicated form of acute pyelonephritis (APN) characterized by single or multiple areas of localised infection in the kidney without liquefaction or abscess. Studies investigating AFBN in adults are scarce.
  
  
  OBJECTIVE
  The present study was aimed at evaluating the prevalence, associated factors, and presence of atypical clinical and radiological manifestations in adult AFBN patients. Also, we developed a clinical prediction model to evaluate the probability of AFBN in patients with APN.
  
  
  METHODS
  The clinical records of 377 patients (mean age 54years, 74.0% females) admitted to a hospital over a 5-year period with APN were reviewed.
  
  
  RESULTS
  A total of 57 cases of AFBN were radiologically identified (prevalence, 15.1%). Patients with AFBN were younger and displayed atypical manifestations more frequently than patients without AFBN; these included both clinical and radiological (pleural effusion, gallbladder wall thickening, fluid around the gallbladder, perirenal fluid, and ascites) manifestations. Patients with AFBN showed lower systolic blood pressure and needed more days of therapy to become afebrile, longer total duration of antibiotic therapy, and longer hospital stay than patients without AFBN. Contraceptive use was more frequent in patients with AFBN. A model based on five clinical variables showed good discrimination performance for the diagnosis of AFBN (Area under the curve, 0.77 (95% CI, 0.69-0.89)).
  
  
  CONCLUSIONS
  Patients with AFBN frequently present with atypical clinical and radiological manifestations. Clinical presentation by means of a predictive model may predict the presence of AFBN. Patients with AFBN need more intensive therapy, which is followed by a favourable outcome.
authors.affiliation: Department of Internal Medicine, Hospital Clinico Universitario, Santiago de Compostela, Spain. Electronic address: xkampos@gmail.com.
authors.forename: Joaquin
authors.initials: J
authors.lastname: Campos-Franco
authors.affiliation: Department of Internal Medicine, Hospital Clinico Universitario, Santiago de Compostela, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: Macia
authors.affiliation: Department of Radiology, Hospital Clinico Universitario, Santiago de Compostela, Spain.
authors.forename: Emilio
authors.initials: E
authors.lastname: Huelga
authors.affiliation: Department of Clinical Epidemiology Unit, Hospital Clinico Universitario, Santiago de Compostela, Spain.
authors.forename: Carla
authors.initials: C
authors.lastname: Diaz-Louzao
authors.affiliation: Department of Clinical Epidemiology Unit, Hospital Clinico Universitario, Santiago de Compostela, Spain.
authors.forename: Francisco
authors.initials: F
authors.lastname: Gude
authors.affiliation: Department of Internal Medicine, Hospital Clinico Universitario, Santiago de Compostela, Spain.
authors.forename: Rosario
authors.initials: R
authors.lastname: Alende
authors.affiliation: Department of Internal Medicine, Hospital Clinico Universitario, Santiago de Compostela, Spain.
authors.forename: Arturo
authors.initials: A
authors.lastname: Gonzalez-Quintela
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001424:Bacterial Infections / Q000150:complications*; D002443:Ceftriaxone / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007668:Kidney / Q000000981:diagnostic imaging; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009393:Nephritis / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000382:microbiology; D011704:Pyelonephritis / Q000150:complications*; D012189:Retrospective Studies; D012307:Risk Factors; D013030:Spain; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D002443:Ceftriaxone
keywords: Acute focal bacterial nephritis; Acute lobar nephronia; Adult; Nomograms; Pyelonephritis