Elevated Paraneoplastic Markers: An Uncommon Finding in Orthostatic Intolerance and Postural Orthostatic Tachycardia (P2.134)

Objective: To identify the frequency of elevated paraneoplastic markers in patients presenting with the autonomic disorders of orthostatic intolerance and postural orthostatic tachycardia syndrome. Background: Postural tachycardia syndrome (POTS) is a common, heterogeneous syndrome that results in postural lightheadedness and a multitude of other symptoms. The exaggerated orthostatic tachycardia and various other symptoms likely result from several pathophysiologically distinct mechanisms. Recently, a number of studies suggest that POTS may have an autoimmune etiology. Paraneoplastic neurologic syndromes are also a heterogeneous group that may affect any part of the nervous system including the autonomic and have causes other than cancer. We evaluated Mayo Clinic Laboratory paraneoplastic markers in our patient population over a two year period. Design/Methods: Medical records of 319 patients presenting for evaluation for suspected Orthostatic Intolerance (OI) in the Autonomic Clinic at Mayo Clinic Arizona from January 1 st 2014 to December 31st 2015 were reviewed. Patients were included if they underwent an Autonomic Reflex Screen and paraneoplastic panel and were diagnosed with OI or POTS. Results: Two hundred sixty eight patients met inclusion criteria, age (30.5 +/− 11) range 12–54, sex (89% female) and ethnicity (99% non-Hispanic white). Eighty-two had OI and 266 POTS. Thirteen (4%) patients mean age twenty-nine, had an elevated Paraneoplastic panel markers, two (0.6%) had elevated Neuronal Type Calcium Channel antibody (Ab), one had elevated P/Q calcium channel Ab (0.3%), four (1%) had elevated Acetylcholine Ganglionic Neuronal Ab, four (1%) had Striated Muscle Ab and two (0.6%) had elevated neuronal (VG) K+ Channel Ab. Conclusions: Elevated paraneoplastic markers did not appear to occur frequently in the OI/POTs cohort studied. However, in the presence of a known debilitating neurological disorder (POTS), with an elevated paraneoplastic marker and in the absence of cancer; a possible immune disorder warrants consideration. Disclosure: Dr. Hoffman-Snyder has nothing to disclose. Dr. Khoury has nothing to disclose. Dr. Goodman has nothing to disclose.