Patients with clonal mast cell diseaseMast cell disease A group of conditions in which mast cells behave abnormally by building up in excess, releasing chemicals too easily or both. Includes mastocytosis, mast cell activation syndrome and hereditary alpha-tryptasemia. (CMD) such as systemic mastocytosis (SM) and Hymenoptera venom allergy (HVA) should receive immunotherapy for at least five years, according to a recently published study in The Journal of Allergy and Clinical Immunology: In Practice.
The term Hymenoptera comprises bees, ants, and wasps. Almost everyone has been bitten by one of these insects at least once. However, in some people, the venom from these insects can cause severe, life-threatening reactions.
“Between 7-26% of patients with HVA are estimated to have a clonal 135 MCD presenting as systemic mastocytosisMastocytosis Rare disease caused by the buildup of mast cells. Cutaneous mastocytosis primarily affects the skin and is more common in children, while systemic mastocytosis affects internal organs and is more common in adults. or monoclonal mast cell activationMast cell activation Describes when mast cells release histamine and other mediators into the blood stream in response to an allergen or other trigger. This leads to symptoms like fatigue, rash and, in severe cases, anaphylaxis. syndrome (MMAS),” the authors wrote.
Having SM is a significant risk factor for suffering from a severe reaction to a Hymenoptera sting. The risk of anaphylaxisAnaphylaxis A severe allergic reaction that can turn fatal without treatment. Patients with SM are at a higher risk of developing anaphylaxis. due to HVA is approximately 19% in patients with an MCD compared to 1% in the general population. In some cases, a severe HVA could be the first manifestation leading to an SM diagnosis.
Learn more about SM signs and symptoms
Patients who suffer a severe HVA should be screened for an MCD using a clinical and laboratory analysis known as the REMA score or examination of the skin in search of mastocytosis lesions. TryptaseTryptase A protein enzyme that is primarily produced by mast cells and stored in small pockets within the cells, known as granules. High levels of tryptase are a key indicator of SM. genotyping and PCR assay are other options available if the attending physician considers the first two methods insufficient.
Patients with HVA and SM should receive preventive treatment to prevent life-threatening episodes. These patients should always carry epinephrineEpinephrine Also called adrenaline, this hormone is used in emergency situations to reverse symptoms during a severe allergic reaction (anaphylaxis). autoinjectors, which are available in case of a sting. In the author’s experience, patients with MCD usually require more than one injection to come out of a crisis.
Immunotherapy is the only effective preventive treatment for severe HVA. In patients with MCD and HVA continued immunotherapy for at least five years is recommended.
“Patients with clonal MCD have a high rate of anaphylaxis due to Hymenoptera envenomation. Often, anaphylactic reactions in these patients are rapid and severe,” the authors wrote. “Therefore, all patients with HVA should undergo screening for SM to determine the pretest probability of SM and whether a diagnostic bone marrow biopsyBone marrow biopsy A procedure to collect a sample of bone marrow using a needle. Often used to examine the characteristics of mast cells and diagnose SM. is warranted.”
