The clinicopathologic characteristics of granulomatosis with polyangiitis (Wegener's): a retrospective study of 45 patients in Korea

The aim of this study was to determine the clinicopathologic characteristics of granulomatosis with polyangiitis (Wegener's) (GPA) in Korean patients. The medical records of 45 patients with GPA treated in a single tertiary referral hospital were retrospectively analyzed with respect to clinical manifestations, including histology, ANCA positivity, disease stage, and disease activity. Patients were categorized into granulomatous, vasculitic, or mixed form based on an immunopathologic scoring system of granulomatous-vasculitic activity. Thirty-one patients (68.9 %) showed ANCA positivity (C-ANCA/P-ANCA, 42.2 %/20.0 %, proteinase-3 (PR3) ANCA/myeloperoxidase (MPO) ANCA, 44.1 %/16.1 %), and these patients (female 48.4 %) were found to be associated with a higher frequency of renal involvement (51.6 vs. 7.1 %, p = 0.004), elevated serum creatinine (29.0 vs. 0 %, p = 0.018), and higher mortality (29 vs. 7.1 %, p = 0.041) than ANCA-negative patients. Thirty-three patients (73.3 %, female 60.6 %) had the granulomatous form, whereas 8.9 and 17.8 % had the vasculitic and mixed forms, respectively. Patients with the granulomatous form were diagnosed earlier in their lives (mean age 51.2 vs. 62.3, p = 0.002) and had a lower frequency of renal involvement (21.2 vs. 100 %, p = 0.005) compared with those with the vasculitic form. Initial remission (69.7 vs. 25.0 %) and relapse (60.8 vs. 0 %) rates were higher for the granulomatous than for the vasculitic form. Taken together, in Korean patients with GPA, the granulomatous form was predominant and associated with a younger age at diagnosis and a lower frequency of renal involvement than the vasculitic form. ANCA positivity was found in 68.9 % and associated with renal involvement and higher mortality.