Bronchiectasis Prevalence in Patients With Primary Humoral Immunodefiency in Champagne-Ardenne Region, France

Common variable immunodeficiency (CVID) and other antibody deficiencies like immunoglobin G subclass deficiency and selective IgM deficiency are the most frequent clinically significant primary immunodeficiencies (PID) in adults. Prevalence in France in 2009 was 2.11/100.000 people.

These immunodeficiencies are characterized by a significant decrease in serum immunoglobulin concentrations and antibodies production. In some patients, qualitative and/or quantitative alterations in B cells repertoire and sometimes in T cells repertoire are observed. Consequently, patients are more prone to bacterial infections, respiratory manifestations, auto-immune diseases, atopic manifestations, neoplastic complications. Respiratory manifestations are the main complication responsible for the morbidity and mortality in PHID. Bronchiectasis are one of the observed pulmonary complications. It is characterized by pathological and permanent dilatation of the airways, as demonstrated by a thoracic CT-scan. Its frequency varies from a study to another, ranging from 20% to 60% in different PHID populations. Some patients with bronchiectasis can be asymptomatic, while others can present daily symptoms of cough and sputum production with periodic worsening of their symptoms (exacerbations). It can lead to chronic respiratory failure, more infectious complications and altered quality of life. Moreover, mortality in patients with bronchiectasis (whatever the cause) is twice as high than in general population.

A thoracic CT-scan is therefore recommended at PHID diagnosis. However, there is no recommendation concerning screening of this complication during follow-up.

Pathophysiology of bronchiectasis in general is described as a cycle of events promoting impaired mucociliary clearance and retention of airways secretions, leading to chronic infection and thus to inflammatory response, leading to abnormal remodeling oh the airways.

To date, it is not known if some PHID patients are more prone to developing bronchiectasis. There is no statistical link with the number of past infectious events. Some studies suggested that patients with lower IgM concentration or lower switched memory B cell might be more at risk.