Spontaneous Post-Transplant Air-Leak Syndrome in Adult Patients Receiving Allogeneic Hematopoietic Stem Cell Transplantation
Authors: Chien Sheng-Hsuan , Liu Yao-Chung , Fan Nai-Wen , Liu Chia-Jen , Chiou Tzeon-Jye , Tzeng Cheng-Hwai , Gau Jyh-Pyng , Liu Jin-Hwang 
Published: November 2019

Abstract
Introduction:
Post-transplant air-leak syndrome (ALS) is a rare but potentially life-threatening complication following allogeneic hematopoietic stem cell transplantation (SCT). All forms of thoracic air leak are defined as ALS, including spontaneouspneumomediastinumorpneumopericardium, subcutaneous emphysema, interstitial emphysema and pneumothorax.The risk factors and pathogenesis of this rare complication have not been well defined, and we reviewed adult patients undergoing hematopoietic SCT in our hospital between January 2003 and December 2014 with focus on this complication.
Method
We reviewed 423 adult patients undergoing allogeneichematopoieticSCT from 2003 to 2014in Blood and Marrow Transplant Center of Taipei Veterans General Hospital in Taiwan. Pre-transplant and transplant-related clinical data including age, sex, pre-transplant biological data, disease diagnosis, comorbidities, type of transplant, human leukocyte antigen matching, conditioning regimens, graft-versus-host disease (GVHD) and other clinical complications were collected for analysis.We used multivariate logistic regression models adjusting for possible independent confounding factors to determine the independent risk factor of ALS. A log-rank test was used to compare survival curves for statistical significance.
Results
Thirteen out of 423 patients (3.07%) developed post-transplant ALS in study period. The median age at SCT was 33 years (interquartile-range: 27-46) and male were predominant (69%) among ALS patients.The median time for ALS development was at 253 days (range: 40-2680) after SCT.Multivariate analysis revealed that grade III-IVacute GVHD(odds ratio [OR] 4.36, 95% confidence interval [CI] 1.30-14.66; p = 0.017), extensive chronic GVHD (OR 4.22, 95% CI 1.26-14.12; p = 0.019) and prior history of pulmonary invasive fungal infection (OR 11.84, 95% CI 1.98-70.69; p = 0.007) were significant risk factors for ALS (Table 1) and a trend as risk factor in patients with age ≤42 years (OR 3.41, 95% CI 0.85-13.67; p = 0.083). In patients with chronic GVHD, those with ALS had significantly worse survival time than those without ALS (log-rank p = 0.04, Figure).
Conclusion
Currently, there are less published data analyzing and exploring post-transplant ALS in adult allogeneichematopoieticSCT. Our study showed a large patient cohort andwe confirmed the risk factors for developing post-transplant ALS, including grade III-IV acute GVHD, extensivechronic GVHD and patients with pulmonary invasive fungus infection history. Patients with young age also had a trend of risk in developing ALS. Patients with post-transplant ALS had a poor survival, especially in patients with chronic GVHD.Prospective studies are needed to determine the etiology andoptimal management of ALS after adult allogeneic hematopoietic SCT.
Figure Figure.

Disclosures
No relevant conflicts of interest to declare.