Wegener's granulomatosis: epidemiological and clinical features in a South Australian study

The epidemiology of Wegener's granulomatosis (WG) has shown a latitude-dependent predisposition in Northern Hemisphere and in New Zealand. There are no studies describing epidemiology or long-term follow up of WG reported from Australia. The aims of this study were to describe the epidemiological and clinical features of WG in South Australia (SA).

The 5-year incidence of WG in SA over the period 2001-2005 was determined using the International Classification of Diseases classification (M313) of the discharge diagnosis using the Integrated South Australian Activity Collection. A retrospective case record analysis of 30 patients fulfilling the American College of Rheumatology criteria for WG and managed at two regional hospitals over a 20-year period (1985-2004) was carried out.

The 5-year incidence of WG in SA was 56 per 10(6) (95% confidence interval 44.1-68.4 per 10(6)). There were no regional or seasonal variations in disease occurrence. The demographic, clinical and serological features in the clinical study were similar to previously published studies. Significant treatment-related morbidity was noted with 50% of patients having atherosclerotic vascular complications. The median survival was 12 years. There were two important periods with greater risk of dying -- in the first 5 years and after 10 years.

The 5-year incidence of WG in SA is higher than that in the same latitudinal region in New Zealand ( approximately 34 degrees S). Atherosclerotic vascular disease was a major long-term morbidity. There is increased incidence of early mortality, warranting the need for earlier diagnosis and better therapies. Further studies from Southern Hemisphere are required for better epidemiological description of this disease.