Autoimmune Basis for Postural Tachycardia Syndrome

Launched by VANDERBILT UNIVERSITY MEDICAL CENTER · Mar 30, 2016

Keywords

ClinConnect Summary

This study, called Autoimmune Basis for Postural Tachycardia Syndrome, is looking to see if some people with Postural Orthostatic Tachycardia Syndrome (POTS) have higher levels of autoantibodies—immune proteins that may attack the body’s own receptors—against parts of the autonomic nervous system. The researchers want to know how common these autoantibodies are in people with POTS compared with healthy adults, whether these autoantibodies relate to standing-related symptoms like a fast heart rate, and if the antibodies stay the same or change over time. To do this, they will perform a series of tests on up to about 58 participants, including blood tests, tests that assess autonomic (automatic) body functions, and some drug- and radiation-based tests, over up to three study days.

Who can join? Adults aged 18 to 50. People with POTS must have a heart rate rise of more than 30 beats per minute within 10 minutes of standing (without a big drop in blood pressure) and have had symptoms for more than 6 months. Healthy volunteers of the same age and gender may join as controls. Exclusions include high blood pressure, pregnancy, certain heart or immune system problems, liver or kidney issues, and other conditions that could affect results or safety. The study is led by Vanderbilt University Medical Center with a collaborating center at the University of Oklahoma, and participation is by invitation. If you’re eligible, you’ll be told exactly what tests you’ll have, including a posture test with blood samples, 24-hour heart and blood pressure monitoring, nerve and blood-flow tests, and selective drug tests, with safety monitored by the study team. No results are available yet, and the trial is not sharing individual participant data publicly.

Gender

ALL

Eligibility criteria

• Inclusion Criteria:
• • 18-50 years old
• • Postural Tachycardia Syndrome: Heart rate increase \>30 bpm from supine within 10 min of standing, in the absence of orthostatic hypotension (\>20/10 mmHg fall in blood pressure), with chronic symptoms (\> 6 months), and in the absence of other acute cause of orthostatic tachycardia.
• • Able and willing to provide informed consent
• • Female premenopausal subjects must utilize adequate birth control and willingness to undergo serum beta-hCG testing
• • The subject must understand and be able to comply with the study procedures and restrictions.
• Exclusion Criteria:
• • Hypertension (\>150 mmHg systolic and \>100 mmHg diastolic) based on history or findings at screening.
• • Orthostatic hypotension (consistent drop in blood pressure \>20/10 mmHg with 10 min stand)
• • Pregnancy
• • Cardiovascular disease, such as myocardial infarction within 6 months, angina pectoris, significant arrhythmia (sinus tachycardia is not excluded), deep vein thrombosis, pulmonary embolism
• • History of serious neurologic disease
• • History or presence of significant immunological or hematological disorders
• • Clinically significant gastrointestinal impairment that could interfere with dietary compliance or drug absorption
• • Impaired hepatic function (aspartate amino transaminase and/or alanine amino transaminase \>1.5 x upper limit of normal range)
• • Impaired renal function (serum creatinine \>1.5 mg/dL)
• • Hematocrit \<28%
• • Current or concurrent disease that could affect the absorption, action or disposition of the drug, or clinical or laboratory assessments.
• • Any underlying or acute disease requiring regular medication that could possibly pose a threat to the subject or make implementation of the protocol or interpretation of the study results difficult
• • Inability to comply with the protocol
• • Healthy control subjects will be healthy, non-smoking and on no chronic medications at the time of the study. Healthy control subjects will be group-matched to the POTS patients for age and gender. We will attempt to study female patients in the first half of their menstrual cycle to minimize cyclical variability.