Renal vasculitis in Japan and the UK--are there differences in epidemiology and clinical phenotype?

Abstract

We identified 27 cases of renal vasculitis (Wegener's granulomatosis 13, microscopic polyangiitis 11, Churg Strauss syndrome 3) fulfilling the case definition. The overall average age was 63.5 years which is less than those of the Japanese patients. The overall annual incidence of renal vasculitis was 12.2/million similar to Japan. The annual incidence of Wegener's granulomatosis was 5.8/million, microscopic polyangiitis 4.9/million and Churg Strauss syndrome 1.4/million. ENT and neurological involvement were much less common in Japan. No patients with cANCA/PR3 were seen in Japan. Wegener's granumolatosis seems to be much less common in Japan than the UK. Discussion. Whilst the overall occurrence of renal vasculitis is similar in Japan to the UK, the clinical phenotype is very different with microscopic polyangiitis predominating in Japan.