Preliminary studies showed that desmosine and isodesmosine levels in biofluids (plasma, urine, and sputum) from COPD patients with or without AATD are increased [112, 113]; one study also showed evidence that AAT augmentation therapy diminished desmosine excretion in AATD patients [114]. The gene discussed is SERPINA1; the disease is alpha 1-antitrypsin deficiency.