Elevated levels of 2,3-dinor-11beta-prostaglandin F2 alpha (2,3 BPG) in urine are not specific for systemic mast cell disease and may be found in patients with angioedema, diffuse urticaria, or myeloproliferative diseases in the absence of diffuse mast cell proliferation.
Systemic mast cell disease is a heterogeneous disease, and some patients may not have elevated 2,3 BPG in urine.
Patients taking aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs) may have decreased concentrations of prostaglandin F2 alpha if dosage has not been discontinued for 2 weeks or 72 hours, respectively.