XeMRI-derived gas-exchange ratios in people with inborn errors of immunity and healthy controls. Violin plots show group differences in hyperpolarized XeMRI ratios: (A) RBC/Gas, (B) RBC/Mem, and (C) Mem/Gas. People with inborn errors of immunity had a higher Mem/Gas ratio (p=0.0459) and lower RBC/Mem ratio (p = 0.0355) compared to healthy controls, with no difference in RBC/Gas ratio (p=0.9019). White-filled points denote individuals with reduced Kco (z < −1.3, <10th percentile). RBC, red blood cell; Mem, interstitial (alveolar-capillary) membrane; Gas, airspaces; HC, healthy controls; IEI, inborn error of immunity; Kco, carbon monoxide transfer coefficient.