Efficacy of immunotherapy in seropositive and seronegative putative autoimmune autonomic ganglionopathy

Objective: To evaluate the efficacy of immunotherapy in the treatment of patients with seropositive and seronegative putative autoimmune autonomic ganglionopathy (AAG) using validated autonomic function tests and instruments. Background: AAG is an immune-mediated disorder characterized by prominent and selective involvement of autonomic nerve fibers or ganglia. Treatment with IV immunoglobulin (IVIg) or plasma exchange (PE) has been reported to be effective in single case reports. Methods: We studied six patients, four with seropositive and two with seronegative putative AAG, who underwent autonomic function tests and completed two validated questionnaires, to assess autonomic symptoms before and after immunomodulatory treatment. Patients were treated with standard doses of IVIg, PE, or immunosuppressants in a specific sequential therapy protocol depending on clinical response. Results: Of the six patients (all women, mean ages 49.3 ± 10.6 years), four patients were ganglionic (α3) AChR autoantibody positive and two were autoantibody negative. All patients showed clinical improvement after treatment. Sudomotor function assessed by quantitative sudomotor axon reflex test and thermoregulatory sweat test improved in four patients after treatment. Conclusions: Immunomodulatory treatment can be effective in both seropositive and seronegative putative autoimmune autonomic ganglionopathy. Plasma exchange or combined therapy with immunosuppressive agents should be considered in patients who do not benefit from IV immunoglobulin alone.