Despite the discordance of the correlation pattern, between MPA and GPA patients, given that in real clinical settings, there are patients classified as both MPA and GPA, patients with unclear boundaries between MPA and GPA, and those whose MPA and GPA diagnoses change over time, we believe that these results may support that peripheral eosinophil count at diagnosis could reflect cross-sectional BVAS and CRP regardless of MPA or GPA patients. Here, CRP is linked to microscopic polyangiitis.