| Antibody (common name; target) | Antigen location | PNS-Care risk category | Common neurologic phenotypes | Common tumor associations | Notes on treatment responsiveness/prognosis |
|---|---|---|---|---|---|
| Anti-Hu / ANNA-1 (neuronal nuclear antigens/Hu) | Intracellular | High risk (>70% cancer association) | Limbic encephalitis, encephalomyelitis, sensory neuronopathy; also high-risk CNS/PNS presentations | Small-cell lung cancer (SCLC) most typical | Intracellular-antigen syndromes are thought to be mainly T-cell mediated; antibodies are diagnostic markers rather than directly pathogenic, and responses to immunotherapy are often limited/variable compared with surface-antibody syndromes (pqac-00000002, pqac-00000003, pqac-00000004, pqac-00000005, pqac-00000007) |
| Anti-Yo / PCA-1 (CDR2/CDR2L) | Intracellular | High risk | Rapidly progressive cerebellar syndrome / paraneoplastic cerebellar degeneration | Breast and ovarian/gynecologic cancers | Typically associated with cerebellar syndrome; intracellular-antigen profile generally predicts poorer immunotherapy responsiveness and often substantial residual disability (pqac-00000001, pqac-00000003, pqac-00000004, pqac-00000007) |
| Anti-Ri / ANNA-2 (Nova) | Intracellular | High risk | Opsoclonus-myoclonus-ataxia syndrome, brainstem/cerebellar syndromes | Breast cancer; also ovarian cancer and SCLC reported with OMS | High-risk onconeural marker; syndrome–tumor pairing helps direct cancer search. As an intracellular-antigen syndrome, prognosis is often driven by rapid recognition and tumor control (pqac-00000002, pqac-00000003, pqac-00000005) |
| Anti-Ma2 / Ta (PNMA2) | Intracellular | High risk | Limbic encephalitis, diencephalic/brainstem encephalitis, encephalomyelitis, cerebellar syndrome | Testicular germ-cell tumors/seminoma most characteristic | High cancer association; phenotype often strongly guides tumor search. Like other intracellular-antigen syndromes, pathogenesis is thought to be T-cell dominant and treatment response less robust than with surface-antibody disease (pqac-00000002, pqac-00000003, pqac-00000005, pqac-00000007) |
| Anti-CV2 / CRMP5 | Intracellular | High risk | Multifocal CNS/PNS syndromes, neuropathy, encephalitic/brainstem/cerebellar presentations | Commonly lung cancer/thymoma in broader PNS literature summarized by reviews | High-risk intracellular marker; often part of multifocal PNS presentations. Clinical course can be severe and requires aggressive tumor search plus immunotherapy/tumor treatment (pqac-00000002, pqac-00000004, pqac-00000007) |
| Anti-amphiphysin (AMPH) | Intracellular/synaptic vesicle-associated | High risk | Stiff-person spectrum disorders; encephalomyelitis/other multifocal syndromes may occur | Breast cancer and SCLC are classic associations in review literature | Considered a high-risk antibody in the updated framework; some cases may show partial immunotherapy responsiveness, but cancer treatment remains central (pqac-00000002, pqac-00000004) |
| Anti-KLHL11 (Kelch-like protein 11) | Intracellular | High risk | Brainstem encephalitis, cerebellar syndrome, hearing-related rhombencephalitic presentations | Testicular seminoma | Newly recognized biomarker highlighted in updated reviews; useful for directing tumor screening in men with brainstem/cerebellar syndromes (pqac-00000005, pqac-00000007) |
| Anti-DNER / Tr (DNER) | Surface-associated neuronal protein | Intermediate risk (30–70% cancer association) | Rapidly progressive cerebellar syndrome | Hodgkin lymphoma | Representative intermediate-risk antibody; phenotype–tumor pairing is clinically useful. Surface/extracellular-associated antibodies are generally more treatment-responsive than classic intracellular onconeural syndromes, though data remain limited (pqac-00000002, pqac-00000003, pqac-00000005, pqac-00000007) |
| Anti-GABA-B receptor (GABABR) | Surface receptor | Intermediate risk | Limbic encephalitis, prominent seizures/intractable epilepsy | SCLC commonly associated | Surface-antibody disorder with clearer direct antibody pathogenicity and generally better responsiveness to immunotherapy than intracellular-antigen PNS; cancer screening is still essential (pqac-00000003, pqac-00000005, pqac-00000006, pqac-00000007) |
| Anti-AMPAR (AMPA receptor) | Surface receptor | Intermediate risk | Limbic encephalitis | Thymoma, lung or breast tumors can be associated in review literature | Cell-surface antibody syndrome; often more immunotherapy-responsive than high-risk intracellular syndromes, though malignancy search remains mandatory (pqac-00000002, pqac-00000005, pqac-00000007) |
| Anti-NMDAR (NMDA receptor) | Surface receptor | Lower risk / not typically classified as high-risk PNS marker | Encephalitis/psychiatric and seizure-predominant syndromes | Ovarian teratoma; testicular germ-cell tumors also reported | May be paraneoplastic or non-paraneoplastic. Surface-antibody mechanism supports direct pathogenicity and typically better response to immunotherapy than intracellular onconeural disorders (pqac-00000001, pqac-00000007) |
| Anti-LGI1 (leucine-rich glioma-inactivated 1) | Surface/secreted synaptic protein | Lower risk | Faciobrachial dystonic seizures, autoimmune encephalitis/limbic encephalitis | Often no tumor identified | Usually not strongly cancer-associated; an important differential when evaluating suspected PNS. Surface-antibody disease is often immunotherapy responsive (pqac-00000001, pqac-00000005, pqac-00000007) |
| Anti-CASPR2 (contactin-associated protein-like 2) | Surface/paranodal membrane protein | Lower risk | Morvan syndrome, encephalitis/peripheral nerve hyperexcitability spectrum | Thymoma can occur, but many cases are non-paraneoplastic | Lower cancer risk than classic onconeural antibodies; often more responsive to immunotherapy than intracellular-antigen syndromes (pqac-00000001, pqac-00000005, pqac-00000007) |


*Table: This table summarizes representative PNS-associated antibodies by antigen location, 2021 PNS-Care risk category, typical neurologic phenotypes, tumor associations, and broad treatment/prognostic implications. It is useful for quickly linking syndrome presentation to antibody interpretation and malignancy search priorities.*