Long-term treatment with rituximab of autoimmune autonomic ganglionopathy in a patient with lymphoma.

OBJECTIVE: To report on the response to therapy in a patient with autoimmune autonomic ganglionopathy with a high titer of an autoantibody directed against the α-3 subunit of the nicotinic acetylcholine receptor (nAChR) of the autonomic ganglia.
DESIGN: Case report.
SETTING: University-based referral center for autonomic dysfunction. PATIENT: Patient with prior indolent B-cell lymphoma who presented with symptomatic orthostatic hypotension and autonomic failure and was found to have a high titer of nAChR antibody. INTERVENTION: Plasma exchange and rituximab therapy (both initial 4-week therapy and maintenance therapy). MAIN OUTCOME MEASURES: Autonomic ganglionic antibody titer; the autonomic assessments were the presence of orthostatic hypotension, the concentration of plasma norepinephrine, and quantitative sweat testing.
RESULTS: Treatment with rituximab followed by plasma exchange significantly decreased the nAChR antibody titers for a short time, and then the titers increased. The titers suppressed to almost undetectable levels once regular maintenance therapy with rituximab was initiated. Reduction in nAChR antibody titer resulted in a decrease in orthostatic hypotension, an increased concentration of upright plasma norepinephrine, improvement in some sweat function, and improvement in symptoms.
CONCLUSIONS: Long-term rituximab therapy suppressed autoantibody production to undetectable levels over the course of 2 years and resulted in sustained clinical improvement in this patient with debilitating autoimmune autonomic ganglionopathy. More data are needed before rituximab therapy can be recommended as routine therapy for this disorder.