On the day after ECMO was established, the patient's immune disorder-related test results were back, with negative anti-nucleic antibody and anti-dsDNA antibody and positive cytoplasmic anti-neutrophil cytoplasmic antibody (c-ANCA) and proteinase3 (PR3) antibodies; we confirmed the patient's diagnosis as GPA. Here, PRTN3 is linked to granulomatosis with polyangiitis.