title: Transient 5-oxoprolinuria: unusually high anion gap acidosis in an infant.
abstract: Transient 5-oxoprolinuria is a phenomenon that is well recognised in adults. We illustrate an unusual paediatric case of transient 5-oxoprolinuria presenting during an episode of severe sepsis with concomitant paracetamol use. The 15-month-old patient had an extremely high anion gap metabolic acidosis. Adequate resuscitation failed to correct the biochemical disturbance, and high levels of 5-oxoproline were identified. A combination of haemofiltration, replenishment of glutathione stores with N-acetylcysteine and cessation of paracetamol administration resulted in the resolution of the acidosis. Subsequent testing following treatment of the sepsis revealed no ongoing 5-oxoprolinuria.
  
  
  CONCLUSIONS
  Transient 5-oxoprolinuria has been previously reported in the adult population during episodes of severe sepsis and various pharmaceutical interventions. This case illustrates that it is a phenomenon that should be considered in paediatric patients where a very high anion gap metabolic acidosis exists that cannot be explained by the biochemical indices.
  
  
  BACKGROUND
  • 5-oxoprolinuria in the paediatric population is usually secondary to an inborn error of metabolism. • Transient 5-oxoprolinuria is well recognised in adults during episodes of severe glutathione depletion.
  
  
  BACKGROUND
  • Transient 5-oxoprolinuria is a phenomenon rarely reported in the paediatric population. • It highlights the importance of investigating a high anion gap such that unusual diagnoses are not missed.
authors.affiliation: Sheffield Children's NHS Foundation Trust, Sheffield Children's Hospital, Western Bank, Sheffield, S10 2TH, UK. Sarah.hulley@nhs.net.
authors.forename: Sarah L
authors.initials: SL
authors.lastname: Hulley
authors.affiliation: Sheffield Children's NHS Foundation Trust, Sheffield Children's Hospital, Western Bank, Sheffield, S10 2TH, UK. Jeff.perring@sch.nhs.uk.
authors.forename: Jeff
authors.initials: J
authors.lastname: Perring
authors.affiliation: Sheffield Children's NHS Foundation Trust, Sheffield Children's Hospital, Western Bank, Sheffield, S10 2TH, UK. Nigel.manning@sch.nhs.uk.
authors.forename: Nigel
authors.initials: N
authors.lastname: Manning
authors.affiliation: Sheffield Children's NHS Foundation Trust, Sheffield Children's Hospital, Western Bank, Sheffield, S10 2TH, UK. Simon.olpin@sch.nhs.uk.
authors.forename: Simon
authors.initials: S
authors.lastname: Olpin
authors.affiliation: Sheffield Children's NHS Foundation Trust, Sheffield Children's Hospital, Western Bank, Sheffield, S10 2TH, UK. Sufin.yap@sch.nhs.uk.
authors.forename: Sufin
authors.initials: S
authors.lastname: Yap
mesh_terms: D000082:Acetaminophen / Q000009:adverse effects*; D000136:Acid-Base Equilibrium; D000138:Acidosis / Q000139:chemically induced* / Q000175:diagnosis; D000592:Amino Acid Metabolism, Inborn Errors / Q000209:etiology*; D018712:Analgesics, Non-Narcotic / Q000009:adverse effects*; D005260:Female; D005981:Glutathione Synthase / Q000172:deficiency*; D006801:Humans; D007223:Infant; D011761:Pyrrolidonecarboxylic Acid / Q000097:blood; D018805:Sepsis / Q000188:drug therapy
chemical_list: D018712:Analgesics, Non-Narcotic; D000082:Acetaminophen; D005981:Glutathione Synthase; D011761:Pyrrolidonecarboxylic Acid
keywords: 5-oxoproline; Anion gap; Metabolic acidosis; Paracetamol; Pyroglutamate