Antibodies found in patients with sCJD or limbic encephalitis
| 150 Sera referred pre-sCJD diagnosis (n=number tests requested) | Positive (% tested) Antibody scores or titres* |
|---|---|
| VGKC-complex (n=119) | 2 (1.7%); 210 pM, 113 pM |
| NMDAR (n=77) | 2 (2.6%); both low positive at 1:20 |
| Paraneoplastic (n=51) | 0 |
| VGCC (n=25) | 0 |
| GAD (n=16) | 0 |
| GlyR (n=6) | 1; low positive initially, rising to positive at 1:20; Also VGKC-complex 210 pM |
| Ganglioside (n=5) | 0 |
| MuSK (n=3) | 0 |
| AQP4 (n=2) | 0 |
| MOG (n=1) | 0 |
| MAG (n=1) | 0 |
| Total positive sera | 4/150 (2.7%) |
| 82 sCJD Sera available for retrospective analysis† | |
| VGKC-complex | 1 (1.2%), confirmed previous requested result |
| NMDAR | 1 (1.2%) low positive at 1:20 |
| GlyR | 2 (2.4%), positive at 1:20; and positive 1:100 |
| CASPR2 | 3 (3.6%) low positive at 1:100, positive at 1:200 and 1:400; each positive for NMDAR (n=1) or GlyR (n=2) antibodies as above |
| LGI1 | 0 |
| Total positive sera | 4/82 (4.9%) |
| Referred after admission to the National Prion Clinic as probable sCJD. Final diagnosis limbic encephalitis | |
| VGKC-complex | 3 (3.6%) >5000 pM, two LGI-Ab positive (titres not determined), one untested. One female given immunotherapy recovered, two untreated males died |
*Details of the patients with positive antibody tests are included in the online supplementary tables. The screening assays were performed as for all routine samples at 1:20 (NMDAR, GlyR) or 1:100 (CASPR2) and the reports based on visual binding scores of 0 (negative), 1–4 (positive with increasing intensity). Low positive at 1:20 (or 1:100 for CASPR2) infers a score of 1.5; positive infers >1.5. Titres are based on further dilutions of serum until the endpoint dilution which gives a score of 1. Normal values based on healthy and disease controls are <1:20 for NMDAR, LGI1 and GlyR and <1:100 for CASPR2.12–14
†All sCJD sera available; postmortem-confirmed n=42; postmortem not performed n=40.
AQP4, aquaporin-4; CASPR2, contactin-associated protein 2; GAD, glutamic acid decarboxylase; GlyR, glycine receptor; LGI1, leucine-rich glioma inactivated 1; MAG, myelin-associated glycoprotein; MOG, myelin oligodendrocyte glycoprotein; NMDAR, N-methyl-d-aspartate receptor; sCJD, sporadic Creutzfeldt-Jakob disease; VGCC, voltage-gated calcium channel; VGKC, voltage-gated potassium channel complex.