Immunoglobulin Replacement Therapy for Immunoglobulin G Subclass 2 Deficient Patients With Bronchiectasis

Bronchiectasis is a common chronic lung condition where patients have permanent airways damage leading to daily symptoms of cough, sputum production and recurrent respiratory tract infections. Preliminary studies in our research group have found a severe deficiency of the immune system as a rare cause of bronchiectasis (called immunoglobulin G subclass 2 deficiency) and occurs in about 1 in 20 bronchiectasis patients. The pilot work shows that these patients have more chest infections and their lung function deteriorates more rapidly. There are no trials to date to guide doctors to decide whether we should replace this deficiency from donated blood or not. The aim with treatment is to prevent disease progression and avoid the need for long term antibiotics. This trial will help us understand how this treatment works and its acceptability to patients. This study will help us decide whether investigators should pursue future formalised trials in many centres throughout the UK and how investigators should evaluate such a treatment. We are looking to recruit 20 patients to this study 10 of which will receive weekly replacement therapy and the remaining 10 will receive standard care.