Recombinant human deoxyribonuclease treatment in hospital management of infants with moderate-severe bronchiolitis

Bronchiolitis is the main cause of respiratory insufficiency in infants, characterized by acute inflammation, edema, necrosis of epithelial cells and increased mucus production. Mucus is mainly purulent and consequently rich in DNA, as derived from nuclei of degenerating neutrophils and epithelial debris. The treatment is mainly supportive; bronchodilators and systemic steroids are often used but do not reduce the length of hospital stay. The aim of our study is to evaluate the efficacy of recombinant human DNase (rhDNase), in infants affected by moderate-severe bronchiolitis. In a randomized double-blind placebo-controlled study, twenty-two infants (12 males) under 6 months of age (median age 1.6 months) were enrolled and randomly assigned to receive either nebulized rhDNase or placebo (saline) at a dose of 2.5 ml once a day for three days. All infants were evaluated, based on a clinical assessment score, on admission and four times daily during the hospitalization. Placebo and study groups were sex- and age-matched and were similar in, terms of clinical severity on admission. No differences were observed between the two groups of patients with regard to the length of hospitalization and clinical score during the days observed. Two out of four infants, all in the study group, presenting atelectasis on chest radiographs, showed a rapid improvement on the first day. RhDNase is not an effective routine therapy in treating infants hospitalized for bronchiolitis and it is not useful in preventing severe forms of the disease. On the contrary, it may be an effective, safe and cost-benefit treatment only in infants with bronchiolitis and massive atelectasis.