ABSTRACT
Adalimumab is a recombinant human monoclonal antibody that blocks the effects of tumor necrosis factor-alpha, and is presently used for treatment of rheumatoid arthritis, with demyelination being a potential adverse effect. A 31 year-old male with seropositive rheumatoid arthritis presented with diarrhea after the second injection of adalimumab. He was treated with ciprofloxacin. In a few days he developed a Guillain-Barrè syndrome confirmed by electromyography, and his cerebrospinal fluid was compatible with meningeal syndrome or partially treated bacterial meningitis. Adalimumab may be associated with the development of demyelination and infectious diseases. Moreover, both the central nervous system and the peripheral nervous system can be affected.