Table 2.
Results table.
| Test | Result | Test | Result |
|---|---|---|---|
| Anti-NMDAR Antibodies* | CSF 09/06/21 detected CSF 12/7/21 Detected (no discernible difference in staining intensity) Serum 24/6/21 detected |
CSF 12/7/21 | Protein 0.39 (ref <0.45 g/L), glucose 3.6 Erythrocytes 74, polymorphs 0, lymphocytes 2 No oligoclonal IgG bands Culture negative Cryptococcal antigen negative |
| Voltage Gated Potassium Channel Antibodies | Not detected | CSF 9/6/21 | Protein 0.31 (<0.45g/L) glucose 3.7 Erythrocytes 0, Polymorphs 0, lymphocytes 0 |
| AMPA receptor antibodies | Not detected | Viral CSF PCR | Serum HSV1 IgG positive, IgM negative CSF HSV 1/2, VZV, CMV, Adenovirus no detected |
| Neuronal antibodies | Negative | Alpha-feto protein | Not elevated |
| Mitochondrial antibodies | Not detected | Syphilis serology | Negative |
| HIV serology | Negative | Hepatitis B + C serology | Negative |
| CASPR2 antibodies | Not detected | CMV serology | IgG positive, IgM negative |
| Non-contrast MRI brain 19/07/21 | No acute intracranial pathology.• In particular no imaging features of autoimmune encephalitis. | CT chest, abdomen, pelvis 14/07/21 | No evidence of solid malignancy. Long-standing occlusion of infrarenal abdominal aorta. |
| Non-contrast MRI brain 19/07/21 | No acute intracranial pathology.• In particular no imaging features of autoimmune encephalitis. | PET 22/07/21 | No FDG evidence of malignancy. Increased metabolism of the parietal, temporal and to lesser frontal cortices. Although non-specific, this is reported as a finding seen in anti-NMDA-receptor encephalitis. |
CSF, cerebrospinal fluid; HSV, herpes simplex virus; VZV, varicella zoster virus; CMV, cytomegalovirus.
Antibody testing was carried out by Pathology Queensland (NATA/RCPA Corporate Accreditation Number 2639) with Health Support Queensland. Anti-NMDA-receptor IgG antibodies were detected in serum and cerebrospinal fluid (CSF) by indirect immunofluorescence using a commercial assay containing four biochips of primate hippocampus, primate cerebellum, fixed NR1-transfected human embryonic kidney 293 (HEK293) cells, and fixed non-transfected control HEK293 cells (IIFT: Glutamate Receptor Mosaic 3, Euroimmun, Lübeck, Germany, UK) (34, 35). When the second sample was received the CSF was tested in parallel with the earlier CSF specimen with no discernible difference in intensity of the staining identified. Dilution base or titre testing is not available in Australian laboratories.