Abstract
BACKGROUND: The role of viruses in children with respiratory tract infections and humoral immunodeficiencies has hardly been studied. We have evaluated these infections in children with humoral immunodeficiencies who required immunoglobulin replacement therapy, considering their relationship with symptoms, lung function, bacterial co-infection, and outcomes. METHODS: We conducted a prospective case-control study during a 1-year period, including children with humoral immunodeficiencies receiving immunoglobulin replacement therapy. For each patient, at least one healthy family member was included. Respiratory samples for viral detection were taken every 1-3 months, and in case of respiratory tract infections. Symptoms questionnaires were filled biweekly. Spirometry and sputum culture were performed in every episode. RESULTS: Sixty-six episodes were analyzed in 14 patients (median age 12 years; IQR 7-17), identifying 18 respiratory viruses (27.3%), being rhinovirus the most frequently isolated one (12/18; 66%). Positive viral episodes were associated with clinical symptoms (89% vs 43%), more frequent antibiotic treatment (44% vs 15%) or hospital admission (22% vs 0%) than negative ones. Patients with positive viral detection showed impaired lung function, with lower FEV1 and FVC values. CONCLUSIONS: In our experience, viral respiratory tract infections can cause significant respiratory symptoms and impaired lung function, in children with HID, despite immunoglobulin replacement therapy. These patients could benefit from the monitoring of viral infections, as these may be a gateway for ongoing lung damage.