Diagnostic Value of Tryptase in Food Allergic Reactions: A Prospective Study of 160 Adult Peanut Challenges.
J Allergy Clin Immunol Pract
; 6(5): 1692-1698.e1, 2018.
Article
in En
| MEDLINE
| ID: mdl-29500041
ABSTRACT
BACKGROUND:
Serum tryptase is useful in diagnosing drug and venom anaphylaxis. Its utility in food anaphylaxis is unknown.OBJECTIVE:
The objective of this study was to determine whether tryptase rises in food allergic reactions, optimal sampling time points, and a diagnostic cutoff for confirming a clinical reaction.METHODS:
Characterized peanut allergic patients were recruited and underwent up to 4 peanut challenges and 1 placebo challenge each. Tryptase was measured serially on challenge days both before (baseline) and during the challenge. The peak percentage tryptase rise (peak/baseline) was related to reaction severity. Receiver operating characteristic (ROC) curves were generated establishing an optimal diagnostic cutoff.RESULTS:
Tryptase was analyzed in 160 reactive (9% anaphylaxis) and 45 nonreactive (placebo) challenges in 50 adults aged 18 to 39 years. Tryptase rose above the normal range (11.4 ng/mL) in 4 of 160 reactions. When compared with baseline levels, a rise was observed in 100 of 160 (62.5%) reactions and 0 of 45 placebo challenges. The median rise (95% confidence interval [CI]) for all reactions was 25% (13.3% to 33.3%) and 70.8% (33.3% to 300%) during anaphylaxis. Peak levels occurred at 2 hours and correlated with severity (P < .05). Moderate-to-severe respiratory symptoms, generalized erythema, dizziness, and hypotension were correlated with a higher peak/baseline tryptase (P < .05). ROC curve analysis demonstrated the optimal cutoff to identify a reaction as a 30% rise (sensitivity 0.53; specificity 0.85), area under the curve 0.72 (95% CI, 0.67-0.78).CONCLUSIONS:
Serum tryptase measurement is valuable in food allergic reactions, and correlates with symptom severity. Comparing peak reaction levels at 2 hours with baseline is essential. A rise in tryptase of 30% is associated with food allergic reactions.Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Peanut Hypersensitivity
/
Tryptases
/
Anaphylaxis
Type of study:
Clinical_trials
/
Diagnostic_studies
/
Observational_studies
/
Prognostic_studies
/
Risk_factors_studies
Limits:
Adult
/
Female
/
Humans
/
Male
Country/Region as subject:
Europa
Language:
En
Journal:
J Allergy Clin Immunol Pract
Year:
2018
Document type:
Article