Apparent elevated creatinine after ingestion of nitromethane: interference with the Jaffe reaction

Area of Science:

• Clinical Chemistry
• Toxicology
• Pediatrics

Background:

• Serum creatinine is a key indicator of kidney function.
• The Jaffe reaction is a common method for measuring creatinine.
• Nitromethane, found in model car fuel, is a potential interfering substance.

Observation:

• A young boy ingested an unknown quantity of model car fuel.
• Initial Jaffe reaction testing showed markedly elevated serum creatinine.
• The patient was clinically well with unremarkable additional investigations.

Findings:

• Enzymatic creatinine testing on the same samples revealed normal levels.
• Nitromethane is known to interfere with the Jaffe reaction assay.
• This interference led to a falsely elevated creatinine result.

Implications:

• Laboratory results must be interpreted alongside clinical presentation.
• Awareness of potential toxin interference is crucial for accurate diagnosis.
• This case underscores the need for specific testing methods when interference is suspected.