Table 2.
Differential diagnoses in patients with slightly elevated serum tryptase levels* but no evidence of mastocyosis in the skin
| Diagnosis | Major cellular source of tryptase |
|---|---|
| Hematologic | |
| Systemic Mastocytosis (SM) | Neoplastic mast cells |
| Chronic myeloid leukemia (CML) | Neoplastic (immature) basophils |
| Chronic eosinophilic leukemia (CEL) | Neoplastic mast cells or basophils |
| Chronic basophilic leukemia (CBL) | Neoplastic (immature) basophils |
| Acute myeloid leukemia (AML) | Myeloblasts |
| Myelodysplastic syndrome (MDS) | Blast cells, basophils or mast cells |
| Myeloproliferative neoplasm (MPN) | Blast cells, basophils or mast cells |
| MDS/MPN overlap neoplasm | Blast cells, basophils or mast cells |
| Myelomastocytic leukemia (MML) | Blast cells and neoplastic mast cells |
| Non-Hematologic Reactive | |
| Allergic reaction (transient increase) | Mast cells |
| Mast cell activation syndrome (MCAS) | Mast cells |
| Atopic disorders | Mast cells |
| Chronic inflammatory disease (CID) | Mast cells |
| Chronic helminth infection | Mast cells |
| Others/Pitfalls/Varia | |
| Chronic severe renal failure | Mast cells |
| Normal healthy individual | Mast cells |
| False positive test result** | - |
*
Total serum tryptase 15-30 ng/mL as assessed by the flouroenzyme-immunoassay (FIA).
**
False positive results have previously been produced in a few patients, sometimes on the basis of heterophilic antibodies.
However, the new generation of the FIA developed more recently, should avoid this problem.