Table 2

Autoantibodies in chronic pain

IgG antibodyAntigenOncologic associationsPain and other neural associations
Autoantibodies with strong evidence of pain causality
Nodal complex IgGsLGI1, CASPR2, CASPR1Infrequent: thymomaIsaacs’ and Morvan’s syndromes include autonomic and muscle hyperexcitability, pain only
GAD65 IgGGAD65Infrequent: thymoma; renal cell, breast, colon, lungDysautonomia with and without pain, myelopathy and spasticity (stiff person syndrome), cerebellar disease
Amphiphysin IgGAmphiphysinFrequent: lung, breast, ovarianFocal or diffuse pain, neuropathy, myelopathy, encephalopathy, cerebellar syndrome
Glycine-receptor IgGGlycine receptor-gated chloride channel receptor (alpha1)Infrequent: breast, thymoma, Hodgkin’sPain, brainstem, ataxia, seizures, with progressive encephalomyelitis with rigidity and myoclonus (PERM) or stiff person syndrome
NMO IgGAquaporin-4Infrequent: breast, thymoma, lymphomaRare root and muscle involvements, painful spasms
Autoantibodies associated with pain with less certain causality
Voltage-gated calcium channel IgGN-type and P/Q-type VGCCCarcinomas: lung, breast or gynaecological (less frequent with P/Q type)Hyperexcitable nerve disorders, including cramp fasciculation, myelopathy and varieties of neuropathy (somatic, sudomotor, painful)
Neuronal ganglionic
AChR IgG (alpha-3)
Neuronal AChR containing alpha-3 subunitsAdenocarcinoma, thymoma, small cell carcinomaPandysautonomic neuropathy, including with Adies pupil, somatic neuropathies, painful small fibre; hyperexcitable nerve disorders
Adrenergic receptor IgGβ2-adrenergic receptor, muscarinic-2 receptor, alpha-1a adrenoreceptorsCancer not described with pain onlyComplex regional pain syndrome-1
  • Modified from Klein CJ with permission. Autoimmune Neurology: Autoimmune-mediated peripheral neuropathies and autoimmune pain 2016.15

  • AChR, acetylcholine receptor; CASPR, contactin-associated protein; GAD, glutamic acid decarboxylase; LGI1, leucine-rich glioma-inactivated 1 protein; NMO, neuromyelitis optica; VGCC, voltage-gated calcium channel.