Antineutrophilic cytoplasmic antibody-associated vasculitis with and without renal involvement: C3 contributes to prognosis, but renal involvement does not.

Although patients with renal involvement had higher ages, lower C3 levels at diagnosis, and poorer prognoses, multivariable analysis demonstrated that the C3 level and age at diagnosis, but not renal involvement, contributed significantly to overall survival. Our results demonstrate the relationship between C3 hidden behind renal involvement and AAV prognosis.