PRETRANSPLANT SMALL-AIRWAY DYSFUNCTION IS ASSOCIATED WITH POSTTRANSPLANT COMPLICATIONS IN ADULT HSCT RECIPIENTS

Caner ÇINAR, Ahmet Mert YANIK, Zeynep MERCANCI, Cansu YILDIZ, Tayfur TOPTAŞ, Işık ATAGÜNDÜZ, Semiha Emel ERYÜKSEL, Sait KARAKURT

Thoracic Research and Practice - 2026;27(Sup1):20-26

Division of Pulmonary Medicine, Marmara University Faculty of Medicine, İstanbul, Türkiye

 

OBJECTIVE: Pulmonary function testing is routinely performed before hematopoietic stem cell transplantation (HSCT), but conventional parameters may not capture subtle airway abnormalities. This study evaluated the association of pretransplant forced expiratory flow between 25% and 75% of forced vital capacity (FEF25-75) with post-HSCT complications in adults. MATERIAL AND METHODS: This retrospective single-center cohort included 83 adults who underwent HSCT between 2016 and 2023. Reduced FEF25-75 was defined as <75% predicted. The primary outcome was a composite of post-HSCT complications. Multivariable logistic regression models were adjusted for age, sex, ever-smoking status, HSCT type, and reduced forced expiratory volume in 1 second (FEV1). Discrimination was assessed using receiver operating characteristic analysis. RESULTS: Overall, 32 patients (38.6%) experienced post-HSCT complications. Complications occurred in 50.0% of patients with reduced FEF25-75 versus 28.9% of those with FEF25-75 >=75% predicted (P = 0.049). Reduced FEF25-75 was independently associated with higher odds of complications [odds ratio (OR): 3.58, 95% confidence interval (CI): 1.28-10.04; P = 0.015]. Reduced FEV1 showed an inverse association (OR: 0.12, 95% confidence interval (CI): 0.02-0.71; P = 0.019). FEF25-75 showed poor standalone discrimination (area under the curve: 0.578, 95% confidence interval (CI): 0.450-0.705). CONCLUSION: Reduced pretransplant FEF25-75 was independently associated with post-HSCT complications, but showed poor standalone discrimination. These hypothesis-generating findings suggest that FEF25-75 may provide information complementary to FEV1, but they do not support its use as an independent predictive test. Larger prospective studies are required.