[Respiratory manifestations associated with cyclic neutropenia and innate immune deficiency (IgG3 deficiency): a case report].

Background: Inborn errors of immunity are a heterogeneous group of diseases caused by a diminished or absent response of one or more components of the immune system. IgG subclass deficiency is more common in childhood, especially in boys than in girls. IgG2 deficiency is the most common, followed by IgG3 deficiency.

Case report: A male pediatric patient experienced respiratory distress of viral and bacterial origin and asthma in his early years, with frequent emergency room admissions and/or hospitalizations. At age 5, he was diagnosed with cyclic neutropenia, so the Pediatric Hematology Department decided to offer conservative treatment. At age 6, he was evaluated by an Otorhinolaryngologist, who diagnosed allergic rhinitis and performed a septumplasty and turbinectomy. At age 7, he was evaluated by an Allergist, with normal laboratory results: immunoglobulin profile, lymphocyte subpopulations, and blood count. Subcutaneous allergen-specific testing was positive. Treatment with subcutaneous immunotherapy was initiated. At age 9, the patient relapsed, with symptoms of upper respiratory tract infection and asthma. Laboratory studies revealed IgG3 deficiency (7.81 mg/dL), so treatment with intravenous immunoglobulin was initiated.

Conclusion: The administration of human immunoglobulin and monoclonal antibodies is associated with a reduction in respiratory symptoms in patients with inborn errors of immunity and a better quality of life.