Background Impaired function of the autonomous nervous system has been described in autoimmune diseases such as systemic lupus erythematodes or Sjoegren syndrome1. Reduced heart rate variability, a feature of autonomic neuropathies, is an isolated cardiovascular risk factor. Patients with ANCA-associated vasculitis have an increased risk for cardiovascular events2. However, the reasons for this elevated cardiovascular risk are largely unknown. While the involvement of the peripheral nervous system in systemic vasculitides is well described, little is known about the involvement of the autonomous nervous system.
Objectives To prospectively assess symptoms and objective parameters of autonomic dysfunction in patients with ANCA-associated vasculitides.
Methods Patients with ANCA-associated vasculitis were enrolled after written consent was obtained. Patients and healthy controls completed COMPASS31, a validated questionnaire addressing symptoms of six autonomic domains (orthostatic, vasomotor, secretomotor, gastrointestinal, pupillomotor, bladder dysfunction) with higher scores reflecting more severe symptoms (maximum score 100)3. Additionally, heart rate variability (mean E/I ratio during deep breathing test), blood pressure response to cold and skin conductance were measured.
Results Up to now, 24 patients and 18 healthy controls have been enrolled in the study. All patients and controls completed the COMPASS31 form. Sofar, 18 patients and 9 controls completed vegetative measurement. Vasculitis patients had significantly higher COMPASS31 total scores (mean 12.99 vs. 6.93; p=0,022). In the subdomain analysis, significant differences were seen in the vasomotor, the bladder and the pupillomotor domain (p=0.012; p=0.012; p=0.030 respectively). There were no significant differences in the mean values for E/I ratio during deep breathing, skin conductance or blood pressure response. However, 6 out of 18 vasculitis patients (33%) had a combination of abnormal E/I ratio and abnormal blood pressure response whereas none of the controls had abnormal reactions in both tests.
Conclusions These preliminary data implie that patients with ANCA-associated vasculitides have an increased burden of symptoms by autonomic dysfunction. With reduced heart rate variability and abnormal blood pressure response to cold, two objective features of autonomic dysfunction were detectable. Thus, autonomic nervous system involvement may deserve further investigation, as it might contribute to disease burden and to increased cardiovascular risk.
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Suppiah R, Judge A, Batra R, et al. A model to predict cardiovascular events in patients with newly diagnosed Wegener's granulomatosis and microscopic polyangiitis. Arthritis Care Res (Hoboken) 2011;63:588-96.
Sletten DM, Suarez GA, Low PA, Mandrekar J, Singer W. COMPASS 31: a refined and abbreviated Composite Autonomic Symptom Score. Mayo Clin Proc 2012;87:1196-201.
Disclosure of Interest None declared