Immunomodulatory treatment in postural tachycardia syndrome: A case series.

Background and purpose: Postural tachycardia syndrome (POTS) is a form of autonomic dysfunction characterized by symptoms of orthostatic intolerance, often accompanied by sudomotor dysfunction and gastrointestinal dysmotility. Recently, evidence has accumulated that in a subset of patients, the pathogenesis of dysautonomia may be immune‐mediated. The aim of the current report was to evaluate the use of intravenous immunoglobulin (IVIG) treatment in patients with progressive and/or refractory immune‐mediated POTS. Methods: We retroactively assessed the effect and tolerance of monthly administered IVIG in six patients using autonomic function testing, standardized symptom questionnaires, and patients' symptom diaries both before and 6 months into IVIG treatment. Objective outcome measures included heart rate increase after 10 min of head‐up tilt as well as duration and anhidrotic area in a thermoregulatory sweat test. Subjective outcome measures were patient reports and symptom ratings from the symptom questionnaire. Results: All patients responded to immunomodulatory treatment, regardless of disease duration. After 6 months of IVIG, symptom severity was reduced by nearly 40%. Autonomic function testing showed improved cardiovascular functioning by 50% and a reduction of anhidrotic areas by one third. Overall, tolerance of IVIG treatment was poor, but could be improved by a reduction in infusion rate, premedication with steroids, and additional intravenous hydration. Conclusions: Using subjective but also standardized objective measures, the case series describes promising effects of IVIG treatment in POTS patients with immune‐mediated dysautonomia. By reducing the infusion rate, pretreatment with steroids, and intravenous hydration, tolerance could be improved, and no patient had to discontinue the treatment. [ABSTRACT FROM AUTHOR]