title: Renal arcuate vein microthrombi-associated AKI.
abstract: OBJECTIVE
  This report describes six patients with AKI stages 2-3 (median admission creatinine level, 2.75 mg/dl [range, 1.58-5.44 mg/dl]), hematuria (five with hemoproteinuria), and unremarkable imaging with an unusual and unexplained histologic diagnosis on renal biopsy.
  
  
  METHODS
  The patients were young adults who presented to two neighboring United Kingdom nephrology centers over a 40-month period (between July 2010 and November 2013). Four were male, and the median age was 22.5 years (range, 18-27 years). Their principal symptoms were flank pain or lower back pain. All had consumed alcohol in the days leading up to admission.
  
  
  RESULTS
  Renal biopsy demonstrated microthrombi in the renal arcuate veins with a corresponding stereotypical, localized inflammatory infiltrate at the corticomedullary junction. All patients recovered to baseline renal function with supportive care (median, 17 days; range, 6-60 days), and none required RRT. To date, additional investigations have not revealed an underlying cause for these histopathologic changes. Investigations have included screening for thrombophilic tendencies, renal vein Doppler ultrasonographic studies, and testing for recreational drugs and alcohol (including liquid chromatography-mass spectrometry of urine) to look for so-called designer drugs. Inquiries to the United Kingdom National Poisons Information Centre have identified no other cases with similar presentation or histologic findings.
  
  
  CONCLUSIONS
  Increased awareness and additional study of future cases may lead to a greater understanding of the underlying pathophysiologic mechanisms that caused AKI in these patients.
authors.affiliation: Department of Renal Medicine, Royal Derby Hospital, Derby, United Kingdom;
authors.forename: Andrew
authors.initials: A
authors.lastname: Redfern
authors.affiliation: Department of Renal Medicine, Royal Derby Hospital, Derby, United Kingdom;
authors.forename: Huda
authors.initials: H
authors.lastname: Mahmoud
authors.affiliation: Department of Histopathology, Nottingham University Hospitals, Nottingham, United Kingdom;
authors.forename: Tom
authors.initials: T
authors.lastname: McCulloch
authors.affiliation: Department of Renal Medicine, Royal Derby Hospital, Derby, United Kingdom;
authors.forename: Adam
authors.initials: A
authors.lastname: Shardlow
authors.affiliation: Department of Renal Medicine, Nottingham City Hospital, Nottingham University Hospitals, Nottingham, United Kingdom; and.
authors.forename: Matthew
authors.initials: M
authors.lastname: Hall
authors.affiliation: Department of Renal Medicine, Nottingham City Hospital, Nottingham University Hospitals, Nottingham, United Kingdom; and.
authors.forename: Catherine
authors.initials: C
authors.lastname: Byrne
authors.affiliation: Department of Renal Medicine, Royal Derby Hospital, Derby, United Kingdom; Division of Medical Science and Graduate Entry Medicine, School of Medicine, University of Nottingham, Nottingham, United Kingdom nicholas.selby@nottingham.ac.uk.
authors.forename: Nicholas M
authors.initials: NM
authors.lastname: Selby
mesh_terms: D058186:Acute Kidney Injury / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology / Q000628:therapy; D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000097:blood; D001706:Biopsy; D001780:Blood Coagulation Tests; D003404:Creatinine / Q000097:blood; D005260:Female; D006417:Hematuria / Q000209:etiology; D006801:Humans; D007668:Kidney / Q000098:blood supply* / Q000473:pathology / Q000503:physiopathology; D008297:Male; D011237:Predictive Value of Tests; D011507:Proteinuria / Q000209:etiology; D020127:Recovery of Function; D012082:Renal Veins / Q000000981:diagnostic imaging / Q000473:pathology; D012307:Risk Factors; D012720:Severity of Illness Index; D016896:Treatment Outcome; D018608:Ultrasonography, Doppler; D006113:United Kingdom; D020246:Venous Thrombosis / Q000175:diagnosis / Q000209:etiology*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D003404:Creatinine
keywords: acute renal failure; arcuate vein; corticomedullary junction; thrombosis