A new case of infantile aggressive systemic mastocytosis (SM) treated with midostaurin has been reported. The case, published in the Annals of Allergy, Asthma, & Immunology, noted the therapy improved the patient’s clinical symptoms without significant adverse events.
The patient was a 3-month-old boy with diffuse pruritic patches and hepatosplenomegaly. His tryptase levels were significantly elevated at 187 ng/mL, and a bone marrow biopsy revealed multifocal mast cell infiltration. A proportion of the mast cells were spindle shaped.
Immunostaining of the mast cells was positive for tryptase, CD117, CD2, and CD30, and a biopsy of the skin revealed mast cell infiltration in the dermis. He had no cytopenias. Genetic analyses showed he had a KIT816V mutation.
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Initial treatment included H1 and H2 antihistamines with oral cromolyn, but 3 months later, he developed a fever and hepatosplenomegaly. Blood testing revealed increased tryptase, anemia, thrombocytopenia, low albumin, and increased prothrombin time.
Krase I, Tiano R, Varghese M, et al. Infantile aggressive systemic mastocytosis treated with oral midostaurin. Ann Allergy Asthma Immun. November, 2022. doi:10.1016/j.anai.2022.08.757