Successful treatment with Omalizumab of a child affected by Systemic Mastocytosis: clinical and biological implications.

BACKGROUND: Pediatric Mastocytosis is a rare and heterogeneous disease, characterized by accumulation of mast cells in the skin (Cutaneous Mastocytosis) and/or, less frequently, in other organs, mainly liver, spleen, bone marrow, lymph nodes and gastrointestinal tract (Systemic Mastocytosis). Patients affected by Systemic Mastocytosis show symptoms caused by  a massive release of mast cell mediators: itching, flushing, abdominal pain, generalized weakness, fatigue and neuropsychiatric disorders. Moreover, children with Systemic Mastocytosis are at greater risk of anaphylactic/anaphylactoid reactions, often poorly controlled by the conventional therapy with antihistamines, mast cells stabilizers and steroids. As a result, children affected by Systemic Mastocytosis have a poor quality of life and suffer the consequence of prolonged steroidal treatment. CASE PRESENTATION: A child with Systemic Mastocytosis and severe symptoms, refractory to symptomatic and steroidal therapy, has been successfully treated with Omalizumab, an anti-IgE monoclonal antibody usually employed in allergic patients with severe asthma and orticaria. The onset of clinical benefit of Omalizumab therapy was extraordinarily rapid, but proved to be strictly dependent on drug administration. The child has become completely and steadily asymptomatic. No other anaphylactic episodes have been reported. Steroid treatment could be definitively withdrawn after the second dose of Omalizumab, and all the other medications were later reduced. Twenty months after beginning, Omalizumab therapy is still ongoing with good symptomatology control; no side effects have been observed so far. CONCLUSIONS: In our experience, Omalizumab is an effective treatment for children affected by Systemic Mastocytosis not responding to conventional medical treatments. The main strengths of this therapy are its rapid and extraordinary efficacy to control the severe mast cells mediator-related symptoms, the lack of side effects and its steroid-sparing effect. However, more extensive and controlled studies in pediatric patients affected by Systemic Mastocytosis are needed to substantiate these promising findings.

Safety of biological therapy in children and adolescents with severe asthma during the COVID-19 pandemic: a case series.

Background and aim  It is still unclear whether patients with severe asthma are at greater risk of developing severe COVID-19, particularly pediatric allergic patients under biologic therapy. Studies targeting pediatric patients are currently limited; thus, this study aims to assess the clinical characteristics of young patients with severe asthma under biological therapies during the COVID-19 pandemic. Methods We collected data from February 2020 to April 2021. Patients with severe asthma treated with biological therapies (omalizumab and mepolizumab) have been enrolled. We described demographic data, clinical features, therapies, comorbidities, and laboratory findings for each patient. For patients who got COVID-19, we also described the severity of the disease, the need for hospitalization, and specific therapy. Results A total of 14 patients were included in the study, 11 (78.6%) of them under treatment with omalizumab and 3 (21.6%) with mepolizumab. We identified four patients (28.6%) who tested positive for SARS-CoV-2. Two patients treated with mepolizumab had an asymptomatic disease, and two patients treated with omalizumab had mild disease. Only one patient with mild COVID-19 required hospitalization and specific therapy because of severe obesity. Conclusions No differences regarding the SARS-CoV-2 infection have been found between the two treatments groups. Furthermore, any poor outcome has been observed, confirming the safety of biological therapies. The limited number of patients enrolled and the lack of a control group did not establish a significant risk for infections for these patients.