Alpha-1 antitrypsin deficiency and computed tomography findings

To investigate the severity of bronchiectasis and associated emphysema and the correlation with phenotype in patients with Alpha-1 antitrypsin deficiency.

The scoring system of Ooi and his colleagues for bronchiectasis was modified to include the degree of dilatation of bronchi in affected segments and degree of emphysema. This was applied to 26 high-resolution computed tomography thorax scans of the study population. All criteria were scored on a scale of 0-3.

Nine patients (35%) were female and 17 (65%) were male. The median age was 56 years (range: 17-76 years). Twenty-one patients had a ZZ phenotype, 3 patients had an MZ phenotype, and 2 patients had an SZ phenotype. The median forced expiratory volume in 1 second/forced vital capacity ratio was 43% (range: 24%-87%). A total of 156 lobes were assessed, and 38 (24%) had evidence of bronchiectasis. The overall median total score in affected patients for the extent of bronchiectasis was 2, and all had a ZZ phenotype. Fourteen patients (54%) had a degree of dilatation score of 1 or more, all had a ZZ phenotype, and 4 (15%) had no evidence of emphysema. Bronchiectasis was seen most commonly affecting the upper lobes.

The ZZ phenotype was associated with bronchiectasis most commonly affecting the upper lobes, with moderate emphysema throughout all lobes. Numbers of patients having the SZ and MZ phenotypes are too small to derive accurate conclusions, but none had evidence of bronchiectasis.