Detection of pulmonary complications in common variable immunodeficiency

Airway and interstitial lung disease are distinct entities in paediatric common variable immunodeficiency

Common variable immunodeficiency (CVID) is a common primary immune deficiency, caused by undefined defects in lymphocyte function, and is treated routinely by immunoglobulin substitution. CVID complications include airway disease (AD) and interstitial lung disease (ILD). It was not known if AD and ILD in CVID have a common immunological aetiology and should be considered separate features of the same disease, or as distinct syndromes that require specialized monitoring and treatment. We used high-resolution computed tomography (CT) to diagnose AD or ILD in paediatric CVID patients. Spirometry and body plethysmography did not differentiate between ILD and AD. Patients with AD (n = 11, 20%) developed more pneumonias while children with ILD (n = 8, 15%) showed immune dysregulation characterized by autoimmune complications, more severe memory B cell reduction and expansion of non-naive cytotoxic T cells. In conclusion, ILD and AD in CVID have dissimilar clinical and immunological characteristics, suggesting distinct aetiology requiring tailored monitoring and treatment of these patient subgroups.

A CT scan score for the assessment of lung disease in children with common variable immunodeficiency disorders

BACKGROUND

The prevalence and severity of structural lung disease in children with common variable immunodeficiency (CVID) disorders is not well known, and a dedicated CT scanning protocol and CT scan scoring system have not been described in this category.

METHODS

This was a cohort study of 54 children (34 CVID, 20 CVID-like disorder) in a stable condition who underwent volumetric inspiratory and end-expiratory CT scans. Scans were scored for airway abnormalities, interstitial and parenchymal lung disease, and lymphadenopathy using a newly developed CT scan scoring system. Scores were normalized to a 0% to 100% scale. Observer agreement was assessed using an intraclass correlation coefficient (Ri). Prevalence and severity of CT scan abnormalities were calculated.

RESULTS

Structural lung disease was common (85%-93%), but usually mild as reflected in the relatively low scores (bronchiectasis score 2.8% +/- 6.4%). Moderate-to-severe bronchiectasis was found in three (5%) patients. Expiratory air trapping was the most common finding, found in 71% to 80%, but often in a mild form; application of a cut off level of > 10% reduced its prevalence to 33% to 38%. In 9% to 15% of all patients, air trapping was the only abnormality. Multiple lung nodules were seen in 24% to 25% and could disappear after corticosteroid treatment. Observer agreement was moderate (Ri 0.6-0.79) to good (Ri > 0.8) for all items and the composite scores, except airway wall thickening.

CONCLUSION

In children with CVID disorders, mild structural lung disease is common. Expiratory CT scans show the most frequent abnormality, air trapping. The occurrence of (silent) lung disease progression and the clinical impact of CT scans require further investigations.