A complex pattern of autonomic dysfunction in familial Mediterranean fever. Results from a controlled cross-sectional...

Autonomic dysfunction (AD) has been described in various chronic inflammatory diseases. Studies of AD in patients with familial Mediterranean fever (FMF) are inconclusive. We aimed to assess AD in a cohort of FMF patients.

Signs and symptoms of AD were investigated in patients with FMF and compared to age and gender matched healthy controls. Symptoms of AD were assessed by COMPASS-31, a validated questionnaire to evaluate orthostatic, vasomotor, secretomotor, gastrointestinal, pupillomotor and bladder function domains. Assessment of objective AD comprised heart rate variability during deep breathing, skin conductance changes during mental arithmetic, blood pressure response to pain and dynamic infrared pupillometry.

25 patients and 25 healthy controls were included and evaluated by COMPASS-31 and objective testing of AD. FMF patients had higher median COMPASS-31 total scores than controls (23.7 vs. 1.6, p=0.024). Significant differences were also found in the secretomotor and gastrointestinal sub-domains (4.2 vs. 0.0; p<0.001 and 8.0 vs. 0.0; p=0.004, respectively). Symptoms of autonomic dysfunction were correlated with patient reported global disease activity (r=0.71; p<0.001) and pain level (r=0.68; p<0.001). There were no differences in heart rate variability (HRV), skin conductance, blood pressure response to pain or sympathetic pupillomotor function between patients and controls. FMF patients revealed impaired parasympathetic pupillomotor function that was not associated with clinical parameters. However, patients that were on IL-1-blocking therapy had better parasympathetic pupillary function than patients on conventional treatment.

FMF patients have AD in terms of symptoms and parasympathetic pupillomotor function. Dynamic pupillometry can provide additional information on autonomic regulation in patients with FMF.