Chest ImagingE2829. Common Variable Immunodeficiency: What Radiologists Should Know
Saad H, Williams P, Spizarny D. Henry Ford Hospital, Detroit, Mi
Address correspondence to H. Saad (Hannans@rad.hfh.edu)
Background Information: Common variable immunodeficiency (CVID) is the most frequently diagnosed primary immunodeficiency with a prevalence of one person in 10,000 to 30,000. Patients with CVID have impaired differentiation of B cells into antibody-producing plasma cells and memory B cells. The lack of specialized immunoglobulins predisposes patients to severe and recurrent sinopulmonary infections. Patients with CVID often go undiagnosed until adulthood, with some studies estimating a mean diagnostic delay of 8.9 years. As such, patients with CVID have a high risk of developing chronic lung disease and bronchiectasis. Imaging in CVID patients is critical, both in making a diagnosis and following complications.
Educational Goals/Teaching Points: We will review the spectrum of thoracic imaging findings in patients with CVID, including the findings of granulomatous and lymphocytic interstitial lung disease (GLILD), a lesser known chronic lung disease in CVID patients.
Key Anatomic/Physiologic Issues and Imaging Findings/Techniques: Thoracic manifestations of CVID include: bronchial wall abnormalities, air-trapping, infections, scarring, and interstitial lung disease, particularly GLILD. Bronchiectasis is common in CVID, and a poor prognostic indicator. Bronchiectasis is usually cylindrical, bilateral, and most common in the middle and lower lobes. Of patients with CVID, 33–43% have small airway involvement, which leads to ventilation abnormalities and chronic obstruction. On high resolution CT, air-trapping appears as mosaic attenuation. CVID patients are particularly susceptible to infections with encapsulated bacteria, which often cause acute consolidation or a bronchiolitis pattern. Recurrent infections in patients with CVID result in scarring, which appears as linear and reticular opacities at the sites of prior infection. It has been estimated that ILD occurs in 10–20% of patients with CVID. GLILD occurs in a subset of patients with CVID and is defined by granulomas and peribronchiolar and interstitial lymphocytic infiltration, consisting of lymphocytic interstitial pneumonia (LIP), follicular bronchiolitis, and lymphoid hyperplasia. The CT findings are nonspecific and GLILD is diagnosed by VATS/open lung biopsy.
Conclusion: CVID is the most common symptomatic congenital immunodeficiency. These patients often go undiagnosed until adulthood, exposing them to the sequelae of excessive sinopulmonary infections. The pulmonary manifestations of CVID include recurrent infections, bronchiectasis, ventilation abnormalities, scarring, and chronic lung disease. Some chronic lung disease in patients with CVID is GLILD, a diagnosis unfamiliar to many radiologists. It is paramount that radiologists recognize the pulmonary manifestations of CVID and suggest an inquiry into a patient’s immune status if such findings are made. Doing so might delay the progression to bronchiectasis and chronic lung disease and perhaps even lower mortality.