title: Clinical characteristics of acute renal failure with severe loin pain and patchy renal vasoconstriction.
abstract: BACKGROUND
  Acute renal failure (ARF) with severe loin pain and patchy renal vasoconstriction (PRV) is a syndrome presenting with sudden loin pain after anaerobic exercise. We aimed to investigate the clinical characteristics and the efficacy of diagnostic imaging studies of patients with this syndrome.
  
  
  METHODS
  We retrospectively selected 17 patients with ARF accompanied by loin or abdominal pain who showed multiple patchy wedge-shaped delayed contrast enhancements on a computerized tomography scan. Information about the clinical characteristics, including the nature of pain and combined symptoms, suspected causes, such as exercise, drug or alcohol intake, and renal hypouricemia, and the results of laboratory and imaging tests were gathered.
  
  
  RESULTS
  The mean age of patients with episodes of ARF accompanied by loin pain was 23.0±6.5 (range 16-35) years old. Pain was mainly located in the loin (70.6%) or abdominal area (76.5%) and continued for approximately 3.5±4.0 days. Exercise was suspected as a primary cause of disease in 12 (70.6%) patients. Maximal serum creatinine was 5.42±3.16 (1.4-12.1) mg/dL 3.1±1.8 (1-7) days after the onset of pain. The peak level of serum uric acid was 9.41±2.91 (6.0-15.8) mg/dL. All of the patients recovered to near-normal renal function, and one patient showed hypouricemia after recovery.
  
  
  CONCLUSIONS
  ARF with severe loin pain and PRV can present with loin or abdominal pain, even without a history of anaerobic exercise. Careful history taking and appropriate imaging studies are critical in the diagnosis and management of this syndrome.
authors.affiliation: Department of Internal Medicine, Seoul National University Hospital, Seoul, Korea.
authors.forename: Jeonghwan
authors.initials: J
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Seoul National University Hospital, Seoul, Korea.
authors.forename: Seong Woo
authors.initials: SW
authors.lastname: Lee
authors.affiliation: Epithelial Systems Biology Laboratory, National Heart Lung and Blood Institute, National Institute of Health, Bethesda, Maryland, United States.
authors.forename: Jae Wook
authors.initials: JW
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Ho Jun
authors.initials: HJ
authors.lastname: Chin
authors.affiliation: Department of Internal Medicine, Seoul National University Hospital, Seoul, Korea.
authors.forename: Kwon Wook
authors.initials: KW
authors.lastname: Joo
authors.affiliation: Department of Internal Medicine, Seoul National University Hospital, Seoul, Korea.
authors.forename: Yon Su
authors.initials: YS
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Seoul National University Hospital, Seoul, Korea.
authors.forename: Curie
authors.initials: C
authors.lastname: Ahn
authors.affiliation: Department of Internal Medicine, Seoul National University Hospital, Seoul, Korea.
authors.forename: Suhnggwon
authors.initials: S
authors.lastname: Kim
authors.affiliation: Department of Radiology, Seoul National University Hospital, Seoul, Korea.
authors.forename: Jeong Yeon
authors.initials: JY
authors.lastname: Cho
authors.affiliation: Department of Internal Medicine, Seoul National University Hospital, Seoul, Korea.
authors.forename: Jin Suk
authors.initials: JS
authors.lastname: Han
keywords: Acute kidney injury; Exercise; Renal hypouricemia; Vasoconstriction