Birgitta Versluijs

Predictors for long-term outcome in children with alloimmune lung syndromes after hematopoietic cell transplantation A.B. Versluys, M.B. Bierings, J.J. Boelens, C.K. van der Ent Manuscript submitted Abstract Allo-immune Lung Syndromes (Allo-LS), including Idiopathic Pneumonia Syndrome (IPS) and Bronchiolitis Obliterans Syndro- me (BOS), have a high impact on non-relapse mortality (NRM) af- ter Hematopoietic Cell Transplantation (HCT). We studied therapy response in children with Allo-LS, looking for prognostic factors for long term outcome. We analyzed the association between Allo-LS free survival and pa- tient characteristics, HCT characteristics, Allo-LS characteristics and initial response to Methyl Prednisolone pulse (MP-pulse) the- rapy in all patients developing Allo-LS after HCT in our center from 2004- 2016. Fifty-three patients were included, median age of 6.9 (0.3-18.8) years; 30 with IPS and 23 with BOS, mean duration of follow up 9.0 (0.9-13.2) years. Overall Allo-LS free survival was 43%. In the group of 24 patients (45%) with initial therapy failure, the survival rate was only 4%. In multivariate analysis mechanical ventilation at time of diagnosis of Allo-LS (HR 3.61, 95% CI 1.49-8.76, p=0.005) and systemic treatment for GvHD prior to the occurrence of Allo- LS (HR 7.46, 95% CI 2.15-25.86, p=0.002) appeared risk factors for poor outcome, whereas positive PCR for Respiratory Virus (RV) from Broncho Alveolar Lavage or Nasal Pharyngeal Aspirate was associated with better outcome (HR 0.32, 95% CI 0.13-0.76, p=0.01). Good responders to initial MP pulse therapy had norma- lization of pulmonary function and an overall survival of 73%. In conclusion, therapy failure in Allo-LS occurs in 45% and has very poor prognosis. Early recognition of these refractory patients is important, and improvement of salvage therapies are needed for better survival after Allo-LS. Blood and Marrow Transplantation Program, Depart- ment of Pediatrics University Medical Center Utrecht (UMCU), Utrecht, The Netherlands A.B. Versluys M.B. Bierings J.J. Boelens U-DANCE Labora- tory of Translatio- nal Immunology UMCU, Utrecht, The Netherlands J.J. Boelens Department of Pediatric Pulmo- nology, UMCU, Utrecht, The Netherlands C.K. van der Ent