Postmortem serum tryptase levels in anaphylactic and non-anaphylactic deaths

Area of Science:

• Forensic pathology
• Toxicology
• Biochemistry

Background:

• Postmortem diagnosis of anaphylaxis is challenging due to a lack of specific biomarkers.
• Mast cell tryptase (MCT) is a marker for mast cell degranulation, with elevated levels observed in postmortem samples of anaphylaxis deaths.

Purpose of the Study:

• To evaluate the impact of cause of death, blood sampling site, sample hemolysis, and opiate presence on postmortem MCT levels.
• To establish the diagnostic utility of postmortem MCT levels for anaphylaxis-associated deaths.

Main Methods:

• Sera were collected from three sites in 189 non-suspicious postmortems.
• Aortic samples from 10 anaphylaxis deaths were analyzed for MCT levels.
• Factors influencing MCT levels, including hemolysis and opiate presence, were assessed.

Main Results:

• Elevated MCT levels (>11.4 μg/L) were found in 57% of aortic, 58% of femoral, and 30% of subclavian samples.
• Aortic MCT levels were significantly higher in anaphylaxis deaths compared to other causes.
• Aortic MCT levels >110 μg/L demonstrated 80% sensitivity and 92.1% specificity for anaphylaxis-associated deaths.

Conclusions:

• Moderately elevated postmortem MCT levels are common.
• Aortic MCT levels exceeding 110 μg/L can support an anaphylaxis diagnosis but should not be solely relied upon.
• Significant variations in MCT levels exist between sampling sites, necessitating site-specific reference ranges.