GYPA and chronic obstructive pulmonary disease: Addition of a protein block to the protocol abrogated most of the non-specific staining (Figure 2A), and serum was tested from 11 participants [5 HC s, 2 patients with ANCA-positive EGPA, 1 with SEA, 1 with moderate asthma (MA), 1 with COPD, and 1 with GPA/AAV; Supplemental Table S2] using the adapted protocol.