Predictive Value of Bronchiolitis Obliterans Syndrome Stage 0p in Chronic Graft-versus-Host Disease of the Lung

• BOS 0p frequently precedes BOS and is significantly associated with the development of BOS.
• Detection of BOS 0p may be a suitable screening tool to identify patients at high risk for BOS, where intervention is likely to be more effective than in more advanced cases with irreversible airway damage.

Bronchiolitis obliterans syndrome (BOS) is a significant post-transplant complication with low survival. BOS stage 0p (BOS 0p) is a parameter detected on pulmonary function tests (PFTs) after lung transplantation to identify patients at risk to develop BOS. We performed a retrospective study on 442 patients who underwent allogeneic stem cell transplant from 2007 to 2011 to evaluate whether development of BOS 0p is a risk factor in this population for BOS. Patients who met criteria for BOS 0p were significantly more likely to develop BOS (hazard ratio [HR], 3.22; P < .001). BOS 0p was significantly associated with a history of lung disease pretransplant (HR, 2.48; P = .001) and chronic graft-versus-host disease (GVHD) outside the lung post-transplant (HR, 23; P < .001). Finally, BOS 0p criteria were adequately sensitive in predicting BOS (85%), with a high negative predictive value (98%). Our findings suggest a routine PFT screening strategy with the intent of detecting BOS 0p, especially among patients with prior lung disease and who developed chronic GVHD, could suitably identify an at-risk population for the development of BOS.