A team of European researchers reported that neither systemic mastocytosis (SM) nor concomitant therapy had a substantial impact on the clinical course of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Findings were published in the Journal of Investigational Allergology and Clinical Immunology.

SM is a hematological disease characterized by the neoplastic proliferation of mast cells, typically affecting the bone marrow, skin, gastrointestinal tract, bones, liver, and spleen. Patients with SM may have comorbidities and organ impairment from mast cell infiltration, possibly increasing their risk of developing SARS-CoV-2 infection. 

In addition, scientists fear that the treatment of SM, which can involve various classes of drugs, may affect the clinical outcomes of patients with SARS-CoV-2 infection.

In the EPICOVIDEHA study, researchers studied 20 patients (11 male and 9 female) with SM who were infected with SARS-CoV-2 (a median time of 60 months from their SM diagnosis). Among the participants, 3 were on antimediator drugs, 6 were on midostaurin, and 8 were not receiving any treatment for SM. The final 3 were on a combination of radiation therapy, hydroxyurea, and midostaurin plus chemotherapy and autologous stem cell transplant therapy for a concomitant hematological neoplasm. 

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Six patients were asymptomatic, 10 had mild infection, 3 had severe infection, and 1 was critically infected. Ten did not receive any treatment for the SARS-CoV-2 infection and were conservatively managed. Others received monoclonal antibodies, antiretroviral therapy, or antiviral therapy. Among the 20 participants, 1 died despite best supportive treatment. 

Another study looked at 24 patients infected with SARS-CoV-2 who had clonal mast cell disorders. None of the patients had a significant increase in mediator release symptoms during infection or treatment for the infection. That study also did not identify any risk factors associated with infection severity or overall survival that were related to the patients’ clonal mast cell disorders. 

“Neither [systemic mastocytosis] itself nor concomitant therapy seem to have a strong impact on the clinical course of SARS-CoV-2 infection,” the authors of the EPICOVIDEHA study concluded. 


Criscuolo M, Salmanton-García J, Fracchiolla N, et al. SARS-CoV-2 infection among patients with mastocytosis: an EPICOVIDEHA reportJ Investig Allergol Clin Immunol. Published online July 26, 2022. doi:10.18176/jiaci.0845