Autoimmune markers and autoimmune disorders in patients with postural tachycardia syndrome (POTS)

Abstract

Objective In recent years, there have been a number of studies suggesting that POTS may have an autoimmune etiology. This study examined whether the prevalence of antinuclear antibodies (ANA), other markers of autoimmunity and co-morbid autoimmune disorders is higher in patients with POTS than in the general population. Methods and results Medical records of 100 consecutive patients with POTS evaluated at our clinic were reviewed. In this cohort (90% females, mean age 32, range 13-54 years), 25% had positive ANA, 7% had at least one positive aPL antibody and 31% had markers of autoimmunity. When compared to the general population, patients with POTS had a higher prevalence of ANA (25% vs. 16%, OR 1.8, CI 1.1-2.8, p<0.05), aPL antibody (7% vs. 1%, OR 7.5, CI 3.4-16.1, p<0.001) and co-morbid autoimmune disorders (20% vs. highest estimated 9.4%, OR 2.4, CI 1.5-3.9, p<0.001). The most prevalent autoimmune disorder was Hashimoto's thyroiditis (11% vs. up to 2%, OR 6.1, CI 3.2-11.3, p<0.001), followed by RA (4% vs. up to 1%, OR 4.1, CI 1.5-11.2, p<0.01) and SLE (2% vs. up to 0.12%, OR 17, CI 4.1-69.7, p<0.001). The prevalence of CVID was very high (2% vs. 0.004%, OR 510.2, CI 92.4-2817.8, p<0.001), while celiac disease showed a nonsignificant trend toward increased prevalence. Conclusion Patients with POTS have a higher prevalence of autoimmune markers and co-morbid autoimmune disorders than the general population. One in four patients have positive ANA, almost one in three have some type of autoimmune marker, one in five have a co-morbid autoimmune disorder, and one in nine have Hashimoto's thyroiditis.