Wegener's granulomatosis: a meta-analysis of 349 literary case reports

We report the results of a meta-analysis of 349 patients with Wegener's granulomatosis (WG) that were described in the literature from 1979 onward. We describe the patients in terms of diagnosis (granulomas present or absent in biopsy samples from various organs, results of the anti-neutrophil cytoplasmic antibody [ANCA) test) and of the clinical impact of renal involvement. Furthermore, we report the incidence of histopathologic lesions that were found in 134 renal biopsy samples. Before and after the development of the ANCA test, the percentage of patients in whom WG was diagnosed with histologically proven granulomas is the same. However, after 1987 the diagnosis of the group without granulomas is frequently supported by a positive ANCA test result. For the entire group we found that patients without renal involvement (N = 82) were reported to have lower erythrocyte sedimentation rate (ESR), lower white blood cell count (WBC), less anemia, less hypertension, less occurrence of joint symptoms, and less multi-organ involvement than patients with renal involvement (N = 267). The most frequently reported lesion in the renal biopsy samples was extracapillary proliferation (70%), followed by fibrinoid necrosis of the glomerular tuft (54%). Renal granulomas were reported in only 7 biopsy samples.