Factors Associated With Mortality and Response to Extracorporeal Photopheresis in Lung Allograft Recipients With Bronchiolitis Obliterans Syndrome

Background. This study was designed to identify factors associated with clinical response to extracorporeal photopheresis (ECP) and mortality after ECP in lung allograft recipients with bronchiolitis obliterans. Methods. Forced expiratory volume in 1 second (FEV1) values obtained 6 months before (baseline) and 6 months after initiation of ECP were used to plot the linear relationship between FEV1 versus time before and after ECP. Response to ECP was assigned when a positive integer was derived after subtracting the baseline rate of decline from the rate of decline 6 months after ECP. Univariate and multivariate logistic regression analyses were used to identify demographic, treatment-related factors or spirometric parameters that may be associated with response to ECP or mortality at either 6 or 16 months after initiation of ECP. Results. Forced expiratory volume in 1 second just before ECP was associated with mortality (P = 0.007) at 16 months after ECP initiation. An FEV1 of 1.50 L or less had a sensitivity of 87% and specificity of 60% to identify patients who died within 16 months after ECP initiation. Patients whose FEV1 decline exceeded 40 mL/month were 12 times more likely to have a response to ECP (P = 0.0001). Patients whose decline in FEV1 before ECP was statistically significant (P < 0.05) were nearly 10 times (P = 0.008) more likely to respond to ECP. Conclusions. Forced expiratory volume in 1 second is an important predictor of mortality, and the response to ECP is influenced by both the extent (>40 mL/mo) and statistical significance of the relationship between FEV1 versus time before ECP initiation. Therefore, earlier bronchiolitis obliterans detection and more timely implementation of ECP (ie, when FEV1 values >1.5 L) should be considered especially in patients with a more aggressive rate of decline of lung function.