Successful treatment of idiopathic mast cell activation syndrome with low‐dose Omalizumab

Abstract

Objectives Idiopathic mast cell disorders, a recently defined and recognised syndrome in clinical practice, are similar to the previously termed non‐clonal mast cell disorder. Patients with idiopathic mast cell activation syndrome (MCAS) suffer all the classical signs of mast cell activation but do not have evidence of mast cell clonality. Furthermore, treatment of these patients can be limited and burdensome in those with refractory symptoms. Methods Here, we describe treatment of a patient with idiopathic MCAS utilising a single monthly subcutaneous injection of omalizumab and review the current classification and therapeutic options for clonal and non‐clonal MCAS. Results Low‐dose omalizumab treatment has successfully led to a 5‐year, sustained clinical response, controlled debilitating symptoms of mast cell activation and allowed for reintroduction and long‐term maintenance of bee venom subcutaneous immunotherapy. Conclusion Low‐dose omalizumab of 150 mg monthly should be considered for maintenance management of patients with idiopathic MCAS for its cost and quality‐of‐life benefits.

Mastocytosis and Mast Cell Activation Disorders: Clearing the Air

“…In steroid-refractory mastocytosis of the skin, ultraviolent phototherapy in combination with or without oral psoralen can be an effective alternative treatment option [ 36 ]. The use of other novel medications such as omalizumab as an intervention has been recommended on a case-by-case basis [ 105 , 106 , 107 , 108 , 109 , 110 , 111 , 112 , 113 ].…”

“…An epinephrine autoinjector should always be prescribed for patients presenting with anaphylaxis or severe systemic reactions including syncope [ 82 , 83 ]. For patients with recurrent episodes of anaphylaxis, the anti-IgE monoclonal antibody omalizumab has been shown to significantly improve symptom control and improve quality of life [ 105 , 106 , 107 , 108 , 109 , 110 , 111 , 112 , 113 ]. Other biologicals that target mast cell regulatory proteins and receptors—KIT, IgE, SIGLEC-8, IL-4 receptors, IL-6 receptors, IL-9, IL-33, tryptase, CD25, and CD30— are in development or undergoing clinical trials [ 117 ].…”

Omalizumab and COVID‐19 treatment: Could it help?

“…OMZ has showed reduction of local nasal mucosal inflammation and improving nasal respiration, in addition to improvement of sinonasal function in patients with chronic rhinosinusitis, 4 a mechanism that could be essential for the initial combating of COVID‐19. OMZ can be used in treatment of patients with different types of MCs disorders, even in low‐dose, 5 mitigating viral‐triggered release of the pro‐inflammatory mediators and risk of subsequent serious complications in COVID‐19 patients. Researchers noted OMZ treatment in vivo restored interferon alpha responses to both rhinovirus and influenza via OMZ‐reduced expression of FcεRI α on the cell surface secondary to OMZ‐reduction of free serum IgE levels, denoting an antiviral potential of OMZ 6 …”

Selecting the Right Criteria and Proper Classification to Diagnose Mast Cell Activation Syndromes: A Critical Review

“…Response to additional drugs, including multitargeted tyrosine kinase inhibitors (in patients with SM, such as midostaurin) and anti-IgE therapy (ie, omalizumab) may be considered an indirect sign of MCA or MCAS. [80][81][82][83][84][85][86][87][88] Agents targeting growth and activation of neoplastic MCs, such as KIT-targeting kinase blockers, are often recommended in advanced SM. [89][90][91][92] For instance, midostaurin is a broadly acting signal transduction inhibitor that recognizes kinase targets (such as SYK) downstream of the IgE receptor.…”