Auto-immune Contribution in Symptom-based Sensory and Autonomic Disorders

Summary

Postural Orthostatic Tachycardia Syndrome (PoTS) is a condition where the heart rate increases when standing up, causing symptoms like dizziness and fainting. It primarily affects young women and can be very disabling, impacting daily life. In addition to the typical symptoms related to standing, people with PoTS also experience unexplained pain and fatigue, which worsen their quality of life. The exact causes of PoTS are still unknown, but it is often triggered by viral infections and some PoTS patients show signs of immune system involvement, such as the presence of certain autoantibodies and other autoimmune conditions. Research on other chronic pain disorders, including fibromyalgia syndrome (FMS), has found that autoantibodies can cause pain by affecting how the nerves work. This study aims to investigate if similar immune-related mechanisms are behind the widespread pain seen in PoTS. This study will also look at how PoTS affects the nervous system by testing nerve activity in participants and assessing the number of nerve fibres in the skin, to check if similar changes can be seen in mice. This study will also involve participants with fibromyalgia syndrome and healthy volunteers.

Conditions

• Postural Orthostatic Tachycardia Syndrome (POTS)
• Fibromyalgia (FM)

Interventions

OTHER

Questionnaire and Physical Exam

Standardised participant questionnaires assessing neurological symptoms, including pain (NPSI, DN4, BPI), fatigue (Fatigue Severity Scale), depression and anxiety (PHQ9 and GAD7) and autonomic dysfunction (Malmo PoTS Score and COMPASS-31).

DIAGNOSTIC_TEST

Nerve conduction studies

Measures how fast an electrical impulse moves through sensory and motor nerves. The test will be used to identify/rule out large fibre peripheral neuropathy.

DIAGNOSTIC_TEST

Microneurography

Electrophysiological technique that can record action potentials from individual peripheral nerve axons in humans. The test will be used to identify/rule out small nerve fibre dysfunction.

DIAGNOSTIC_TEST

Quantitative Sensory Testing

Measures psychophysical sensory perception in response to different types of stimuli, such as thermal, mechanical, pressure and vibration. The test will be used to identify/rule out nerve fibre dysfunction, by generating a quantitative sensory profile of different sensory modalities.

DIAGNOSTIC_TEST

Skin biopsy

Safe and minimally invasive procedure to quantify intraepidermal nerve fibres density (IENFD). Reduced IENF density is associated with small fibre neuropathy.

BIOLOGICAL

Blood Product

A blood sample of a maximum of 120ml will be collected from a superficial upper limb vein. Blood aliquots (50ml tubes) will then be centrifuged to separate serum from the peripheral blood cells.

Sponsors & Collaborators

• King's College Hospital NHS Trust

  collaborator OTHER

• Guy's and St Thomas' NHS Foundation Trust

  collaborator OTHER

• King's College London

  lead OTHER

Eligibility

Min Age

18 Years

Max Age

80 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2025-10-31

Primary Completion

2029-10-31

Completion

2030-10-31