Secondary immunodeficiency and non-cystic fibrosis bronchiectasis.

Abstract

Bronchiectasis is a chronic respiratory disease characterized by the abnormal dilation of the bronchi that causes cough, sputum, and recurrent infections. Identifying the underlying cause is a critical aspect of managing bronchiectasis because it may be associated with various respiratory or systemic diseases. Immunodeficiency is a rare but important cause of bronchiectasis, and its treatability is a significant trait for bronchiectasis management. Primary immunodeficiencies in bronchiectasis are well recognized, but secondary immunodeficiencies remain under-reported and under-researched. Secondary immunodeficiencies may result from various diseases and conditions, such as hematologic malignancies, human immunodeficiency virus infection, renal transplantation, and the use of immunosuppressive drugs, and may contribute to the occurrence of bronchiectasis. Recurrent pulmonary and/or extra-pulmonary infections in bronchiectasis may indicate the presence of secondary immunodeficiency in patients with these underlying conditions. Regarding treatment, examining the underlying condition, managing bronchiectasis adequately, and prophylactic antibiotics (e.g., macrolide) and/or supplementing immunoglobulin G therapy may provide potential benefits. Considering the projected increase in the prevalence of secondary immunodeficiencies and bronchiectasis, future guidelines and research on the diagnosis and optimized treatment are needed.