An Unusual Case of Polyautoimmunity with Concomitant Presentation of Postural Tachycardia Syndrome, Antiphospholipid Syndrome and Hashimoto’s Thyroiditis

Abstract

Introduction: Postural tachycardia syndrome (POTS) is a chronic form of autonomic dysfunction characterized by symptoms of orthostatic intolerance, often accompanied by sudomotor dysfunction and gastrointestinal dysmotility. In a subgroup of patients with POTS, autoantibodies against adrenergic or cholinergic receptors suggest an immune-mediated etiology. Antiphospholipid syndrome (APS) is a hypercoagulative autoimmune disorder associated with anti-phospholipid-antibodies that causes arterial and venous thromboses. Concurrent occurrence of APS and immune-mediated POTS is rare. Methods and Results: Here, we report a 28-year-old female that experiences symptoms of orthostatic intolerance, vasovagal syncopes, gastrointestinal dysmotility and sudomotor dysfunction. She fulfills the formal diagnostic criteria of POTS showing a heart rate increment of ≥30 beats per minute (bpm) within 10 m of head-up tilt in the absence of orthostatic hypotension, accompanied by symptoms of orthostatic intolerance. The thermoregulatory sweat test reveals severe patchy anhidrotic areas. Gastric emptying scintigraphy shows an impaired gastrointestinal motility. Plasma norepinephrine levels and a skin biopsy appear normal. Finally, serological persistence of anti-alpha-1-adrenergic autoantibodies suggest an immune-mediated pathogenesis. Several years after initial presentation of POTS symptoms, the patient develops APS with recurrent venous emboli and persistent anti-phospholipid-antibodies. Recently the patient is diagnosed with Hashimoto’s thyroiditis (HT) expressing high levels of thyroid-stimulating hormone and high titers of anti-thyroid antibodies. Conclusion: To our knowledge, this is the first report of consecutive immune-mediated POTS, APS and HT in a young woman, possibly displaying a unique combination of three disorders of autoimmune etiology.