Paranodal disease with anti-contactin-associated protein 1 antibodies: a case report and literature review / 中华神经科杂志

ABSTRACT

Objective:To summarize the clinical, pathological and molecular biological characteristics of one patient of paranodal disease with anti-contactin-associated protein 1 (Caspr 1) antibodies.Methods:The patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) admitted to Qilu Hospital of Shandong University from August 2018 to December 2020 were retrospectively studied. The clinical data of one acute onset CIDP patient with anti-Caspr 1 antibodies were collected and retrospectively analyzed with literature review. Anti-nodal/paranodal IgG and their subclasses in serum and cerebrospinal fluid (CSF) were investigated by immuno?uorescence assays. Pathological characteristics were explored by sural nerve biopsy further.Results:The patient presented with tremor, ataxia and neuropathological pain besides symmetrical limb muscle weakness and hypaesthesia. The CSF protein was elevated significantly. The brachial plexus and lumbosacral plexus magnetic resonance imaging showed enlarged nerve roots. The patient was responsive well to intravenous immunoglobulin and steroids in acute phase, while the symptoms improved significantly with rituximab in chronic phase. Autoantibodies against Caspr 1 were detectable in serum and CSF, with IgG4 predominant. Sural nerve biopsy revealed segmental demyelination and myelin digestion chamber. Dispersed lamellae of myelin sheath and axonal degeneration were confirmed by electron microscopy.Conclusions:Tremor, ataxia, neuropathic pain, significantly elevated CSF protein and enlarged nerve roots are suggestive of paranodal diseases with anti-Caspr 1 antibodies. For patients with suspected Guillain-Barre syndrome/CIDP and above phenotypes, nodal/paranodal antibodies and antibody subtypes should be detected to optimize the treatment.