A Pilot Study of Azithromycin Prophylaxis for Acute Chest Syndrome in Sickle Cell Disease

Acute chest syndrome (ACS), a lung complication in sickle cell disease (SCD), is the second most common cause of hospitalization and leading cause of death in SCD. ACS is associated with airway inflammation, and a major cause is pulmonary infection from atypical organisms. To date, there are no drugs available to reduce inflammation and risk of recurrent ACS. Macrolides are a group of antibiotics that exert immunomodulatory and anti-inflammatory actions both in vitro and in vivo. In addition, macrolides reduce bacterial burden in the airway of atypical organisms, all of which play an important role in the pathophysiology of ACS. Numerous studies have evaluated macrolide prophylaxis in conditions associated with lung inflammation, such as cystic fibrosis, asthma, bronchiectasis etc., and high quality evidence have found macrolides to be beneficial as a disease modifying agent that leads to improvement in airway inflammation, reduced pulmonary exacerbations and improved lung function. The investigators hypothesize that azithromycin prophylaxis is well tolerated and has the potential to reduce inflammation and improve lung outcome in children with SCD with a history of ACS. A prospective, single arm, open label feasibility study of azithromycin prophylaxis will be performed in children with SCD with a history ACS with the specific aim to examine the feasibility, safety and tolerability of azithromycin prophylaxis administration in participants with SCD , and to examine whether azithromycin prophylaxis has the potential to improve lung outcome. In addition, this study will determine whether azithromycin prophylaxis reduces inflammation in participants with SCD with a history of ACS.