Background Little data is available regarding the epidemiology of systemic vasculitides (SV), particularly on their incidence. Available data is heterogenous and often derived from referral centers or small populations.
Objectives To assess the incidence of systemic vasculitides in a stable population by registering all newly diagnosed patients in a large region in North Germany. To investigate the epidemiology and pattern of SV and particularly ANCA-associated vasculitis (AAV) over twelve years in a prospective study.
Methods Since 1/1/98 all newly diagnosed cases of SV as defined by the Chapel Hill Consensus Conference 1992 were identified in a large mixed rural/urban northern German region consisting of 2,83 million habitants in a population-based prospective study. The following sources were used: (a) departments of all hospitals, including their outpatient clinics; (b) all departments of pathology, and (c) the reference immunological laboratories serving the catchment area. All cases were re-evaluated by the authors.
Results Within the observation period of twelve years 1614 patients were identified as having a new diagnosis of SV in the catchment area, 473 patients with giant cell arteritis (GCA) and 434 with ANCA-associated vasculitis (granulomatosis with polyangitis (GPA), microscopic polyangitis (MPA), Churg-Strauss-Syndrome (CSS)) were observed, incidence rates were 14 (range 9-17)/million/year (95% CI 7;21) and 13 (range 8-16)/million/year (95% CI 6;20), respectively. The incidence rates for all SV were between 40 and 54 cases per one million/year with a mean incidence rate of 48/million/year. Incidence rates of GPA were two to three times higher than MPA and CSS. The incidence rates were stable between 1998 and 2010, our observations did not reveal significant differences. People 50 years and older were at a three to five-fold higher risk to get SV compared to those younger than 50 years.
Conclusions Results of our population based vasculitis register over twelve years assessing the incidence of PSV in a region of 2.83 million habitants in north Germany demonstrate stable incidence rates for all SV. Variances between years have been observed, but no pattern or periodicity. Compared to other studies investigating small regions or referral centers the incidence rates for AAV were comparable to the incidence rates observed in Norway, Sweden and the United States, lower than those in United Kingdom, but higher than in Spain and Vilnius. The incidence rates of MPA are significantly higher in Japan, whereas GPA and CSS have not been diagnosed. AAV and giant cell arteritis present with similar incidence rates.
Disclosure of Interest None Declared