Abstract
The diagnosis of bronchiolitis obliterans syndrome (BOS), an obstructive lung disease that occurs following hematopoietic stem cell transplantation (HCT), is clinically challenging due to the presence of pulmonary infections. We evaluated parametric response mapping (PRM) as an indicator of BOS in HCT patients with acute pulmonary infection. PRM was performed in four subject cohorts: HCT patients diagnosed with acute infection (n=11), BOS (n=34), BOS plus infection (n=9), and age-matched, non-HCT subjects (n=23). The PRM analysis includes a 3D map and joint density histogram of voxels color-coded based on classification: green for normal, yellow for fSAD, red for emphysema and purple for parenchymal disease. Presented in the figure is the PRM analysis of a HCT recipient with BOS that was found to have extensive fSAD (yellow; PRMfSAD=40%). Significantly greater PRMfSAD values were identified in patients with BOS (38±2%) as compared to infection alone (17±4%, p<0.0001) and age-matched subjects (8.4±1%, p<0.0001). Negligible differences in PRMfSAD were observed in patients with BOS, whether a concurrent infection was present or not. PRM is a useful indicator of BOS even in the presence of concurrent pulmonary infection. The PRM biomarker may provide a significant advance in the ability to definitively identify the non-emphysematous small airway obstruction characteristic of BOS.
- © 2014 ERS