Table 2.
Antibodies against surface antigens.
| Antigen | Tumor | Main clinical symptoms | Predominant antibody subclass | Most widely used test methods |
|---|---|---|---|---|
| CENTRAL NERVOUS SYSTEM | ||||
| NMDAR | Ovarian teratoma (58% in patients >18 years) | Encephalitis | IgG1 | Unfixed TBA; live/fixed CBA |
| LGI1 | Rarely (thymoma) | LE, faciobrachial dystonic seizures, hyponatremia | IgG4/IgG1 | Unfixed TBA; live/fixed CBA |
| CASPR2 | Thymoma (38%) | LE, cerebellar ataxia, Morvan syndrome, peripheral nerve hyperexcitability | IgG4/IgG1 | Unfixed TBA; live/fixed CBA |
| AMPAR | SCLC, breast, thymoma (60%) | LE, psychosis | IgG1 | Unfixed TBA; live/fixed CBA |
| GABABR | SCLC (50%) | LE, ataxia | IgG1 | Unfixed TBA; live/fixed CBA |
| GABAAR | Thymoma, others (25%) | Status epilepticus, seizures, encephalitis | IgG1 | Unfixed TBA; live CBA |
| mGluR1 | Hematologic diseases (30–40%) | Cerebellar ataxia | NA | Unfixed TBA; live/fixed CBA |
| mGluR5 | 55% paraneoplastic (Hodgkin, SCLC) | Limbic dysfunction, movement disorders; | IgG1/IgG3 | Unfixed TBA; live/fixed CBA |
| DPPX (Kv4.1) | Follicular B cell lymphoma, CLL | Hallucinations, agitation, myoclonus, tremor, seizures, diarrhea | IgG4/IgG1 | Unfixed TBA; live/fixed CBA |
| IgLON5 | – | Non-REM and REM-sleep disorder, brainstem and limbic dysfunction | IgG4/IgG1 | Unfixed TBA; live/fixed CBA |
| GlyR | Lung cancer | SPS, PERM, epilepsy | IgG1 | Unfixed TBA; live CBA |
| Dopamine 2R | – | Basal ganglia encephalitis, Sydenham's Chorea | NA | Unfixed TBA; live CBA |
| Neurexin3alpha | – | Seizures, orofacial dyskinesias | IgG1 | Unfixed TBA; fixed CBA |
| PQ-type VGCC | SCLC | LEMS, PCD | NA | RIA |
| ANTIBODIES IN DEMYELINATION | ||||
| AQP4 | Rarely | NMOSD, LETM, ON | IgG1 | Unfixed TBA; live/fixed CBA; ELISA |
| MOG | – | ADEM, ON, LETM (conus), TM, NMOSD, seizures | IgG1 | Live/fixed CBA |
| Antigen | Associated diseases | Main syndrome | Predominant antibody subclass | Most widely used test methods |
| PERIPHERAL NERVOUS SYSTEM | ||||
| Neurofascin155 | Atypcial CIDP with distal sensomotoric neuropahty, tremor, ataxia, CNS-demyelination | IgG4 | Unfixed TBA; fixed CBA; teased fibers; ELISA | |
| Neurofascin186 | IgG4-related disease; nephrotic syndrome | Subacute onset, severe phenotype, sensory ataxia | IgG4/IgG3 | Fixed CBA; teased fibers; ELISA |
| Contactin1 | Rarely nephrotic syndrome | Atypical CIDP with GBS-like onset, tremor, ataxia | IgG4/IgG3* | Unfixed TBA; fixed CBA; teased fibers; ELISA |
| CASPR1 | CIDP, GBS, neuropathic pain | IgG4, IgG3* | Unfixed TBA; fixed CBA; teased fibers | |
IgG3 were found in patients with GBS or in the acute phase of CIDP and may switch to IgG4 in the chronic phase of the disease (5, 6). NMDAR, N-methyl-D-aspartate receptor; TBA, tissue based assay; CBA, cell-based assay; LGI1, leucine-rich glioma-inactivated 1; LE, limbic encephalitis; CASPR2, contactin-associated protein-like 2; AMPAR, amino-3-hydroxy-5-hydroxy-5-methyl-4-isoxazolepropionic acid receptor; GABA A/B R, gamma-aminobutyric acid A/B receptor; mGluR1/5, metabotropic glutamate receptor type 1/5; NA, not available; DPPX, dipeptidyl-peptidase-like protein-6; CLL, chronic lymphatic leukemia; GlyR, Glycine receptor; SPS, stiff-person syndrome; PERM, progressive encephalomyelitis with rigidity and myoclonus; P/Y-type VGCC, P/Q-type voltage gated calcium channel; LEMS, Lambert-Eaton myasthenic syndrome; RIA, radioimmuno assay; AQP4, aquaporin 4; NMOSD, neuromyelitis spectrum disorder; LETM, longitudinally transverse myelitis; ON, optic neuritis; MOG, myelin oligodendrocyte glycoprotein; ADEM, acute disseminated encephalomyelitis; TM, transvers myelitis; CIDP, chronic inflammatory demyelinating polyneuropathy; GBS, Guillain-Barré syndrome.