MPO and anti-neutrophil cytoplasmic antibody-associated vasculitis: TGF at AAV diagnosis in patients with MPA or those with MPO-ANCA (or P-ANCA) positivity tended to be slightly elevated compared to that in patients with GPA and EGPA or those with MPO-ANCA (or P-ANCA) negativity (p = 0.064 and p = 0.116, respectively).