Table 1

Clinical–serological details of patients with antibodies against the intracellular aspects of Kv1.1, Kv1.2 and/or Kv1.6

Serological resultsClinical featuresDisease aetiologyOutcome and treatmentsSummary of clinical–serological correlations
Age/SexVGKC complex antibody (pM)Kv1-HEK RIAKv1-fixed CBA
59/M1346+1.2 onlyCryptogenic TLE with amnesia/depressionUnknownNo sustained response to three AEDs and CSPoor. Persistent VGKC-c Abs despite markedly varied SZ frequencies. Online supplementary figure S3C
49/F767+1.2 onlyNMT with EMG confirmationAutoimmuneLimited response to AEDs and CSPoor. Highest VGKC-c Abs during clinical remission
55/M533+1.2 onlyNMT with EMG confirmationAutoimmuneSymptoms over 8 years despite AEDs/AZA/CSGood. Patient symptomatic with persistent VGKC-c Abs
77/M470+1.2 onlyChronic myelopathy/encephalopathyUnknownTransient response to CS and PLEXPoor. High VGKC-c Abs despite symptom fluctuations over 3 years
21/M461+1.2 onlyCryptogenic probable frontal lobe epilepsyUnknownOngoing SZs despite two AEDsPoor. Online supplementary figure S3E
50/M448+1.2 onlyIsolated amnesiaUnknownSpontaneous resolution over a few daysPoor. Abs reduced over 12 months. Symptoms resolved at 7 days
28/F278+1.2 onlyCryptogenic TLEUnknownSZ freedom after first AEDPoor. Persistent VGKC-c Abs during SZ freedom
62/M236+1.2 onlyCryptogenic TLE with amnesiaUnknownSZs and amnesia at 5 years with 3 AEDsPoor. VGKC-c Abs disappeared while SZs were ongoing
18/M141+1.2 onlyLimbic encephalitisAutoimmuneGood response to CS and PLEXGood. VGKC-c Abs reduced and clinical improvement at 12 months
25/F529+1.6 onlyDiffuse neuropathic pain and depressionUnknownNo response to opioids, CS or IVIGPoor. High VGKC-c Abs despite marked fluctuations in symptoms
30/F117+1.6 onlyIdiopathic generalised epilepsyGeneticGood response to AEDsNA
68/M240+1.6 onlyAlzheimer's disease; one SZDegenerativeOngoing fall in memory despite CS/IVIGPoor. Slight fall in VGKC-c Abs but marked reduction in memory over 4 years
34/M577+1.2 and 1.6Widespread neuropathic painUnknownNo response to CS, IVIG and PLEXPoor. Constant pain despite highly varied VGKC-c Abs. Online supplementary figure S3D
71/F2489+1.1, 1.2 and 1.6NMT plus SCLCParaneoplasticPalliative care onlyNA.
67/F2120+1.1, 1.2 and 1.6LEMS plus Hu antibody neuropathy and SCLCParaneoplasticGood response to CSPoor. Persistently high VGKC-c Abs over 5 years despite clinical improvements
84/F282+1.1 onlyParkinson's disease dementiaDegenerativeNo response to CSPoor. VGKC-c Abs reduced over 12 months despite clinical worsening
58/M304+NegativeDysautonomiaUnknownNANA
37/M253+NegativeTLE related to left HSStructuralNANA
59/M236+NegativeHealthy smokerHealthyNot relevantNot relevant
48/F223+NegativeTLE related to left HSStructuralNANA
85/F205+NegativeCryptogenic focal motor SZsUnknownSZ free on 1 AED. Amnesia and anxiety benefited from CS/IVIGPoor. VGKC-c Abs disappeared over 1 year; SZ freedom at 2 years. VGKC-c Abs returned at 4 years without SZs
33/F182+NegativeCryptogenic TLEUnknownSZ freedom after second AEDModerate. VGKC-c Abs reduced over 6 months and SZ freedom at 1 year
76/M181+NegativeCryptogenic epilepsyUnknownSZ freedom with 1 AEDPoor. SZ freedom at 6 months; VGKC-c Abs sampled after 15 years
54/F139+NegativeEpilepsy after childhood meningitisStructuralNANA
22/M137+NegativeCryptogenic epilepsyUnknownSZ freedom after 1 AEDNA
54/M131+NegativeCryptogenic epilepsyUnknownSZ free at 1 year with 1 AEDModerate. SZ free at 1 year; VGKC-c Abs absent at 3 months
77/M123+NegativeTLE secondary to CVAStructuralOngoing SZs at 4 yearsNA
  • Patients grouped by the VGKC-c antibody levels, precipitation from Kv1.1/Kv1.2/Kv1.6-cotransfected HEK cell and Kv1.2-transfected HEK cell radioimmunoassays (Kv1-HEK RIA; denoted as positive (+) or negative (−)) and the Kv1 subunit expressed fixed CBAs (Kv1-fixed CBA). All these patients had negative results in live CBAs for antibodies against Kv1s, LGI1, CASPR2, contactin-2 and for binding to live hippocampal neurons. Two patients had SCLC and tumours were not found in the remaining patients.

  • Ab, antibody; AEDs, antiepileptic drugs; AZA, azathioprine; CASPR2, contactin-associated protein-2; CS, corticosteroids; CBA, cell-based assay; CVA, cerebrovascular accident; EMG, electromyography; F, female; HEK, human embryonic kidney 293T; HS, hippocampal sclerosis; IVIG, intravenous immunoglobulins; LEMS, Lambert-Eaton myasthenic syndrome; LGI1, leucine-rich glioma-inactivated 1; M, male; NA, not available (only single serum sample obtained); PLEX, plasma exchange; SCLC, small cell lung carcinomas; SZ, seizure; TLE, temporal lobe epilepsy; VGKC, voltage-gated potassium channel; VGKC-c, VGKC complex.