Prevalence of Takayasu arteritis in Southern Sweden low, comparable to Europe
Takayasu arteritis is uncommon in Southern Sweden, but rates are higher than previous estimates and comparable to rates in other parts of Europe, according to recently published research.
Researchers studied 983,419 patients from three health care centers in the southernmost Swedish county of Skåne, of whom 195,766 were born outside of Sweden. The patients represent about 10% of the country’s total population. Women comprised 50.5% of the population overall and 49.2% of the patients older than 40 years of age.
Patient records were evaluated to confirm the diagnosis, and only patients who met American College of Rheumatology (ACR) 1990 criteria were included in the study. All radiologic information available was assessed to determine the distribution of arterial lesions. Treatment and the vasculitis damage index (VDI) data were collected, and pregnancy and pregnancy outcome data were collected before and after diagnosis.
Twenty-nine patients with a diagnosis of Takayasu arteritis (TA) were initially identified from records from the departments of rheumatology, nephrology and vascular medicine at hospitals in the region, and private practices were also asked if any patients had been treated for TA.
After case evaluation and restriction to patients who lived within the study area, a total of 13 patients with TA were identified. Ten patients were diagnosed between 1997 and 2011 and three living patients were diagnosed prior to 1997.
Median age at diagnosis was 23 years. Swedish ancestry was seen in eight patients, whereas two patients were of Arab descent and one each was of either Asian, African or northern European descent.
The annual incidence rate of 0.7 patients per million was calculated based on the 10 patients diagnosed between 1997 and 2011, and an incidence rate of 1.5 patients per million was calculated for women, specifically.
Mean annual incidence in patients older than 40 years of age was calculated as 1.1 case per million residents, and in women older than 40 years, the rate was 2.3 per million. A rate of 0.6 per million was calculated for inhabitants of Swedish ancestry. The point prevalence was estimated at 13.2 per million and 26.2 patients per million in women, and at 10.2 per million in patients of Swedish ancestry, according to the researchers.
At the final recorded assessment, median VDI score was 5 for all patients. Eight patients had severe organ damage, and two developed critical damage. Damage related to treatment was seen in three patients. The peripheral vascular system was most commonly affected, followed by the cardiovascular system. Five patients (38%) underwent eight surgical and two endovascular interventions.
Twenty-three pregnancies in 10 women were identified, 16 of which occurred prior to diagnosis and resulted in 15 live births. Seven pregnancies occurred after diagnosis of TA and resulted in five live births.
The prevalence of TA is twofold higher than in prior studies and comparable to studies in Denmark and the U.K., according to the researchers. – by Shirley Pulawski
Disclosure: The research was supported by grants from the Swedish Rheumatism Association (Reumatikerförbundet), the Swedish Medical Association (Läkarsällskapet) and the Faculty of Medicine, Lund University.