Amphiphysin is a non-intrinsic membrane protein that is concentrated in nerve terminals. The serum of patients with stiff-person syndrome often contain antibodies to this protein. Stiff-person syndrome (SPS) is a neurological disorder characterized by progressive muscle stiffness (rigidity) and repeated episodes of painful muscle spasms.
Antiamphiphysin antibodies react with a 128-kd protein found in synaptic vesicles. Studies suggest that they can also occur in patients with other tumors and neurological disorders.
References:
Antoine JC, Absi L, Honnorat J, et al. Antiamphiphysin Antibodies Are Associated With Various Paraneoplastic Neurological Syndromes and Tumors. Arch Neurol. 1999;56(2):172–177. doi:10.1001/archneur.56.2.172
Saiz A, Dalmau J, Butler MH, et al Anti-amphiphysin I antibodies in patients with paraneoplastic neurological disorders associated with small cell lung carcinoma, Journal of Neurology, Neurosurgery & Psychiatry 1999;66:214-217.
Lancaster E, Martinez-Hernandez E, Dalmau J. Encephalitis and antibodies to synaptic and neuronal cell surface proteins. Neurology. 2011 Jul 12;77(2):179-89. PMID: 21747075
Balint B, Vincent A, Meinck HM, Irani SR, Bhatia KP. Movement disorders with neuronal antibodies: syndromic approach, genetic parallels and pathophysiology. Brain. 2018 Jan 1;141(1):13-36. PMID: 29053777
Graus F, et al. Updated Diagnostic Criteria for Paraneoplastic Neurologic Syndromes. Neurol Neuroimmunol Neuroinflamm. 2021 May 18;8(4):e1014. PMID: 34006622
Anti-Amphiphysin (IgG + IgA)
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