[Bronchiectasis in the elderly. Study of serum levels of immunoglobulin G subclasses]

To analyze the serum levels of immunoglobulin G (IgG) subclasses in a broad range of elderly patients with bronchiectasis.

Data were collected from all patients who had a high-resolution chest computerized axial tomography diagnosis of bronchiectasis in our center. We gathered data related to case history, respiratory symptoms, forced spirometry, general laboratory tests, immunoglobulin concentration (including IgG subclasses), Mantoux test, sputum culture and staining, paranasal sinus X-rays/computerized axial tomography, and a specific etiologic evaluation based on the available clinical evidence.

A total of 128 patients were included -mean age (standard deviation): 71.6 (5.1) years; range: 65-88; 44.5% males- and 20.3% of them had chronic sputum colonization with Pseudomonas aeruginosa. 28.1% cases had a post-infectious nature and in 40.6% the etiology was unknown. Sixteen patients (12.5%) had decreased levels of at least one of the sIgG compared to normal values. The most frequent deficiency corresponded to IgG2 levels. These subjects showed a characteristic profile of bronchiectasis with an increased lung extension of the disease (p = 0.02); greater presence of cylindrical and diffuse bronchiectasis (p = 0.02 and 0.01, respectively), greater percentage of an unknown etiology (p = 0.004); greater presence of paranasal sinus X-ray abnormalities (p = 0.004) and increased number of past repeated upper airway infections (p = 0.03).

Decreased serum levels of IgG subclasses might be associated with a characteristic profile of bronchiectasis in elderly patients in whom other etiologies have been ruled out.