Emergence of Rheumatoid Arthritis Following Exposure to Natalizumab

We report a patient with relapsing-remitting multiple sclerosis, who developed rheumatoid arthritis after exposure to natalizumab. While some multiple sclerosis therapies are known to unmask autoimmune conditions, natalizumab is rarely implicated as a cause of alternative autoimmunity. This case illustrates an unusual clinical scenario which may support recent scientific work suggesting that when natalizumab blocks T helper 1 cells from entering the central nervous system, T helper 17 cells may continue to migrate into immune-privileged spaces and cause pathologic inflammation.Brief Background: Multiple sclerosis (MS) patients often suffer from concurrent autoimmune conditions, and may be at increased risk for developing rheumatoid arthritis [1,2]. While alemtuzumab and rituximab are known to unmask underlying autoimmune disorders, natalizumab is not commonly associated with autoimmunity. Here, we report a patient with relapsing-remitting MS who developed acute autoimmune arthropathy following exposure to natalizumab.Case Report: A 45-year-old woman with autoimmune thyroiditis presented after episodes of left arm and right leg numbness. MRI showed multiple supratentorial and spinal cord demyelinating lesions. Lumbar puncture yielded CSF with a lymphocytic pleocytosis (11 leukocytes, 97% lymphocytes), normal protein, normal glucose, elevated immunoglobulin G index (2.24), and multiple unmatched oligoclonal bands. Her initial autoimmune workup revealed elevated anti-thyroid per...
Source: Multiple Sclerosis and Related Disorders - Category: Neurology Source Type: research