e-Table 1.
Control group: The mean age of the controls was 10.8 (2.9) years (Table 1 ). C-SCD had lower DLCO/VA, FVC(%pred), FEV1(%pred), TLC (%pred), and VC(%pred) compared to controls (Table 1 ). Race/ethnicity and gender distributions were not statistically different between cases and controls (Table 1) .
Evaluation of DLCO predictors: The correlations between hemoglobin-adjusted DLCO with PFT estimates, anthropometrics, and biomarkers are presented in Table 2 . DLCO was moderately and positively correlated with FEV1(%pred), FVC(%pred), FEV1/FVC, FVC25-75(%pred), TLC(%pred); and inversely correlated with R5Hz(%pred) and with peripheral blood neutrophilia (either a percent of WBC or as absolute counts). Aspartate Aminotransferase (AST), total bilirubin, and LDH had a positive correlation with hemoglobin-adjusted DLCO. However, those associations were driven by the strong correlation between the laboratory results and hemoglobin (e-Table 2 )30, and thus they were not included in further analyses to prevent over-adjustment bias.