Hermansky-Pudlak syndrome: radiography and CT of the chest compared with pulmonary function tests and genetic studies
The objective of our study was to describe the chest radiographic and high-resolution CT findings in patients with Hermansky-Pudlak syndrome and to correlate the radiologic findings with age, causative gene, and pulmonary function. Sixty-seven patients with Hermansky-Pudlak syndrome underwent high-resolution CT of the chest. A scoring system based on the extent of pulmonary involvement and specific high-resolution CT findings was used, and the findings were compared with patient age and the results of pulmonary function and genetic studies. Fifty-eight (87%) of the 67 patients also underwent chest radiography. These radiographs were compared with the high-resolution CT scans. High-resolution CT was more sensitive than chest radiography in evaluating the extent of pulmonary disease in patients with Hermansky-Pudlak syndrome. All patients with mild findings on high-resolution CT scans had normal findings on chest radiographs. Common chest radiographic findings included reticulonodular interstitial pattern, perihilar fibrosis, and pleural thickening. High-resolution CT showed septal thickening, ground-glass opacities, and peribronchovascular thickening. For patients with Hermansky-Pudlak syndrome who were 30 years old or younger, high-resolution CT findings were usually minimal. Among patients who were older than 30 years, the 34 patients with HPS1 mutations had a score of 1.38+/-0.18 (mean+/-standard error of the mean) on high-resolution CT. This score is significantly greater than the score for the 11 patients without HPS1 mutations (0.36 +/- 0.15) (p < 0.001). The score based on high-resolution CT findings inversely correlated with percentage of forced vital capacity and was useful in defining the progression of interstitial disease. High-resolution CT provides a good radiologic monitor of disease status and progression in patients with Hermansky-Pudlak syndrome and correlates well with patient age, extent of pulmonary dysfunction, and genetic findings.