Is postural tachycardia syndrome an autoimmune disorder? And other updates on recent autonomic research

Excerpt

Whether autoimmunity is involved in the pathophysiology of postural tachycardia syndrome (POTS) is a controversial and still undefined topic. When autoantibodies against ganglionic nicotinic acetylcholine receptors were first identified 20 years ago, it became clear that high titers were associated with severe autonomic failure including orthostatic hypotension, tonic pupils, and gastrointestinal and bladder abnormalities, a syndrome now referred to as autonomic autoimmune ganglionopathy (AAG). However, some patients with POTS also tested positive with low titers [13]. Autonomic experts now agree that positivity for ganglionic nicotinic antibodies at low titer (i.e., below 0.2 nmol/L) has no clinical relevance for POTS, as these can be detected in up to 5% of healthy controls [9, 12, 14]. …