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Transient 5-oxoprolinuria: unusually high anion gap acidosis in an infant
Sarah L Hulley1, Jeff Perring2, Nigel Manning3
1Sheffield Children's NHS Foundation Trust, Sheffield Children's Hospital, Western Bank, Sheffield, S10 2TH, UK. Sarah.hulley@nhs.net.
Insights
Transient 5-oxoprolinuria, a condition typically seen in adults, can occur in children during severe sepsis and paracetamol use. This case highlights its importance in pediatric metabolic acidosis diagnosis.
Area of Science:
- Pediatric Critical Care Medicine
- Clinical Biochemistry
- Neonatal and Pediatric Sepsis
Background:
- Transient 5-oxoprolinuria is recognized in adults with severe glutathione depletion, often linked to sepsis or drug use.
- In children, 5-oxoprolinuria is typically associated with inborn errors of metabolism.
- This condition is rarely reported in the pediatric population.
Observation:
- An unusual case of transient 5-oxoprolinuria in a 15-month-old child presenting with severe sepsis and paracetamol (acetaminophen) use.
- The patient exhibited extreme anion gap metabolic acidosis unresponsive to initial resuscitation.
- High levels of 5-oxoproline were detected, indicating significant metabolic disturbance.
Findings:
- Treatment involved haemofiltration, N-acetylcysteine to replenish glutathione, and discontinuation of paracetamol.
- This multi-faceted approach successfully resolved the metabolic acidosis.
- Post-sepsis treatment, the patient showed no further signs of 5-oxoprolinuria.
Implications:
- Transient 5-oxoprolinuria should be considered in pediatric patients with unexplained severe high anion gap metabolic acidosis.
- This case underscores the need for thorough investigation to avoid missing rare diagnoses.
- Early recognition and appropriate management can lead to favorable outcomes in pediatric cases.
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.
Conclusion:
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.
What Is Known:
• 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.
What Is New:
• 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.
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