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

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.