Abstract 701: Risk of Wegener´s Granulomatosis Among Close Relatives of Patients with the Disease
Phil Seo, M.D.
Authors
A. Knight, S. Sandin, J. Askling
Background
Wegener’s granulomatosis is an autoimmune disease of unclear etiology that predominantly affects the respiratory tract and kidneys, and is associated with blood vessel wall inflammation and the formation of necrotizing granuloma. We have long suspected that genetics plays an important role in conferring risk, although its true impact is unknown. This important study examines the risk of developing Wegener’s granulomatosis among close relatives of a patient diagnosed with this disease.
Methods
The purpose of this study was to identify the frequency of Wegener’s granulomatosis among first degree relatives of patients who had already carried this diagnosis, and to compare that frequency to that observed in a control population. The Swedish national patient registry was used to identify 1994 patients who carried a diagnosis of Wegener’s granulomatosis and their 6670 first-degree relatives. The registry was also used to identify a random control population of 19,655 Swedish patients without Wegener’s granulomatosis and their first-degree relatives.
Results
Of the 1994 patients with Wegener’s granulomatosis studied, only one had a first-degree relative who was also diagnosed with this disease. In the control population, 13 patients with Wegener’s granulomatosis were identified, none of whom were closely related to someone who also carried this diagnosis. The relative risk of Wegener’s granulomatosis in a first degree relative was therefore 1.56 (95% confidence interval 0.35-6.90). Of note, none of the spouses of the patients in this study had been diagnosed with Wegener’s granulomatosis as well.
Conclusions
The absolute risk of developing Wegener’s granulomatosis in a first degree relative is quite small, and likely no different from the risk experienced by the general population.
Editorial Comment
Often, the first thing that a patient newly diagnosed with Wegener’s granulomatosis wants to know is whether his or her children might be at risk of developing this disease as well. The results of this comprehensive study of Wegener’s granulomatosis demonstrate that the risk is quite small, and will finally allow many patients to breathe a sigh of relief. It is important to note that this study relied solely on medical databases; no effort was made to confirm the diagnosis of Wegener’s granulomatosis either in the patient or the first degree relatives. Therefore, it seems possible that some cases—particularly among the first degree relatives—may have been missed. Because of the large numbers of participants in this study, however, it seems unlikely that such cases would have dramatically swayed the results.
