Double Positive of Anti-contactin-1 Antibody and Anti-ganglioside Antibodies related Chronic Inflammatory Demyelinating Polyradiculoneuropathy: a Case Report

Abstract

Abstract Background：Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a crippling sickness that worsens over time. Contactin-1(CNTN1) antibody-related CIDP was rare and exhibited distinct clinical symptoms such as a later onset, subacute onset of weakness, sensory ataxia, and tremors. The mechanism of the unusual symptoms remained unknown. So far, no instance of anti-CNTN1 antibody-positive CIDP with anti-ganglioside antibodies (aGAAb) has been reported. Case Presentation: We reported a rare case of anti-CNTN1 antibodies and aGAAb linked CIDP with two episodes. In the first episode, a 45-year-old woman was admitted to our hospital with primary complaint of arm numbness, weakness, and oedema in the lower limb. The physician considered the diagnosis of CIDP after clinical examination. Patient’s symptoms improved after taking prednisolone. Eleven years later, the symptoms were numbness and weakness in all four limbs, accompanied by tremors, which had rapidly deteriorated for nearly 3 years. The protein concentration in CSF was 1344 mg /L, and the white blood cells count was 5 × 106 /L. The serum CNTN1 antibody was positive, with a titer of 1:1000+. Anti-GT1a and anti-GQ1b antibodies in serum were shown to be double positive. There were no evident abnormalities in the brain MRI, brachial plexus, or lumbosacral MRI. Neurophysiological examination indicated that the electrophysiological shift was worse than previously. At the time, she was diagnosed with CIDP caused by the anti-contactin-1 autoantibody and double-positive anti-ganglioside antibodies. Numbness and weakness in the lower extremities were somewhat relieved after plasmapheresis therapy. However, she could still not walk without assistance two weeks after being discharged from hospital. Conclusion：We presented a rare case of double positive of anti-CNTN1 antibody and aGAAb associated CIDP. The mechanism of tremors in patients with positive CNTN1 antibodies, as well as the relationship between aGAAb and CIDP, should be studied further.