AUTONOMIC NERVOUS DYSFUNCTION IN SYSTEMIC LUPUS-ERYTHEMATOSUS (SLE) AND RHEUMATOID-ARTHRITIS (RA) - POSSIBLE PATHOGENIC ROLE OF AUTOANTIBODIES TO AUTONOMIC NERVOUS STRUCTURES

Autonomic nervous dysfunction has been previously reported in SLE, RA and systemic sclerosis, but the pathogenesis of such a complication is poorly understood. In the present study, four standard cardiovascular autonomic function tests were performed in 34 female patients with co nnective tissue diseases and in 25 healthy control subjects, and resul ts expressed as cardiovascular (CV) test scores. Moreover, in each sub ject the presence of circulating complement-fixing autoantibodies dire cted against sympathetic and parasympathetic nervous structures, repre sented by superior cervical ganglia and vagus nerve, respectively, was simultaneously assessed by an indirect immunofluorescent complement-f ixation technique, using rabbit tissue as substrate. None of the patie nts reported autonomic symptoms. However, an abnormal CV test score (g reater than or equal to 5) was detected in 15% of the patients and in none of the healthy control subjects, approaching statistical signific ance (P = 0.07). No correlation was found between CV test results and disease duration, type of therapy or presence of conventional autoanti bodies. One or two autoantibodies to autonomic nervous structures were detected in six patients (18%) and not in the control subjects (P < 0 .05). Values of deep breathing test were significantly lower in autoan tibody-positive patients compared with those amongst the control subje cts (P < 0.05), and an abnormal CV test score was significantly associ ated with the presence of autoantibodies to autonomic nervous structur es (P < 0.05). In conclusion, we confirm that autonomic nervous functi on can be impaired in patients with connective tissue diseases, and su ggest that autoantibodies directed against autonomic nervous system st ructures may play a role in the pathogenesis of the autonomic dysfunct ion.