From the Guidelines
The management approach for a patient with elevated tryptase levels should focus on identifying and treating the underlying cause, with a priority on ruling out anaphylaxis and monitoring for systemic mastocytosis, as recommended by the most recent guidelines 1. To determine the appropriate management, it is crucial to obtain a thorough history to differentiate between acute and persistent elevations. For acute elevations suggestive of anaphylaxis, administer epinephrine (0.3-0.5 mg IM for adults, 0.15 mg for small children) as first-line treatment, followed by H1 antihistamines like diphenhydramine (25-50 mg) and H2 blockers such as famotidine (20 mg) 1. In cases of persistent elevations, referral to an allergist/immunologist for comprehensive evaluation, including bone marrow biopsy if systemic mastocytosis is suspected, is necessary. Treatment for systemic mastocytosis may include daily cetirizine 10 mg and famotidine 20 mg twice daily for symptom control, with sodium cromoglycate (200 mg four times daily) added for gastrointestinal symptoms. Severe cases may require mast cell stabilizers like ketotifen (1-2 mg twice daily) or leukotriene antagonists such as montelukast (10 mg daily) 1. Regular monitoring of tryptase levels is essential to assess disease progression and treatment response, as tryptase serves as a specific marker of mast cell activation and burden 1. Patients should avoid identified triggers and carry emergency epinephrine, emphasizing the importance of patient education and awareness in managing elevated tryptase levels and preventing anaphylactic episodes 1.
Key considerations in the management include:
- Differentiating between acute and persistent tryptase elevations to guide treatment
- Early administration of epinephrine in suspected anaphylaxis
- Comprehensive evaluation for systemic mastocytosis in persistent cases
- Patient education on trigger avoidance and emergency epinephrine use
- Regular monitoring of tryptase levels to assess treatment response and disease progression.
Given the complexity and potential severity of conditions associated with elevated tryptase levels, a multidisciplinary approach, including allergists/immunologists and other specialists, may be necessary to optimize patient outcomes 1.
From the Research
Management Approach for Elevated Tryptase Levels
Elevated tryptase levels can be indicative of various conditions, including anaphylaxis, systemic mastocytosis (SM), and mast cell activation syndrome (MCAS) 2, 3, 4. The management approach for a patient with elevated tryptase levels depends on the underlying condition.
Diagnostic Evaluation
- Serum tryptase levels should be measured to diagnose anaphylaxis and systemic mastocytosis 2, 4.
- A complete workup of each patient is necessary to interpret tryptase levels in the context of their clinical presentation 4.
- The diagnosis of SM requires evidence of dense mast cell infiltrate, presence of KIT D816V mutation, and elevated serum tryptase level (>20 μg/L) 2.
- MCAS should be considered in case of severe and recurrent typical clinical signs of systemic mast cell activation involving at least two organs, associated with an increase in serum tryptase level of 20% + 2 μg/L from the individual's baseline 2.
Interpretation of Tryptase Levels
- Normal serum tryptase range is 0-11.4 μg/L 2.
- Elevated tryptase levels can be caused by various conditions, including anaphylaxis, SM, MCAS, acute myelocytic leukemia, and end-stage renal failure 3, 4.
- Tryptase levels >20 μg/L are associated with SM and MCAS 2, 3.
- The consensus equation (peak MCT should be > 1.2x baseline tryptase + 2 ng/L) can be used to diagnose acute mast cell activation (aMCA) 5.
Clinical Practice
- Tryptase is currently the most specific mast cell biomarker available in clinical laboratories 6.
- Tryptase levels contribute to the diagnostic, prognostic, and therapeutic evaluation of immediate hypersensitivity reactions, clonal mast cell diseases, and hereditary α-tryptasemia 6.
- The practicing clinician should be aware of the pathophysiology and methods regarding mast cells and tryptase to interpret tryptase test results accurately 6.