When Your Own Immunity Attacks Your Brain: The Autoimmune Encephalitis Panel, Explained

The five questions every family asks

Is this the same as meningitis or a viral brain infection? No, but the confusion is understandable. Doctors rule out infection first and never delay antiviral treatment while waiting for antibody results. This is the immune system's own fire, not an invader.

My panel came back negative. Does that mean we are safe? Not quite. Some patients carry antibodies science has not named yet, and occasionally the antibody shows up only in spinal fluid. A negative report is one data point, not the verdict.

The report says a titre of 1:100. Does a higher number mean worse disease? Reports read "detected" plus a titre, the dilution at which the antibody still shows up. Titres vary between labs, and a falling titre does not reliably mean the patient is improving. The doctor's exam is the better guide.

Will a home visit cover everything? Only half. The blood part, yes: our phlebotomist can collect it at your doorstep, cotton ball taped to your arm in minutes. Spinal fluid needs a lumbar puncture, strictly a doctor's job in a hospital or clinic. Never let anyone draw CSF at home.

How long do results take, and do we wait to start treatment? Turnaround is around 8 to 10 days, and nobody waits: treatment typically starts on clinical suspicion alone, because early treatment is the single biggest factor in recovery.

Why your doctor wants both blood and spinal fluid

This is the part families question most, and the reason is solid. Some antibodies are simply easier to catch in one sample: anti-NMDA receptor antibody appears in spinal fluid in essentially every case but is missed in blood in a fair number, while anti-LGI1 is most reliably caught in serum. Testing both is not repetition, it is coverage.

One timing rule: draw blood before IVIG or plasma exchange, since those therapies flood the body with outside antibodies and muddy the result. If treatment has already started, say so on the request form.

The CSF autoimmune encephalitis panel runs on the spinal fluid sample and complements the blood test. If you are comparing autoimmunity tests, our ANA blood test article explains how autoantibody titres and patterns read on a report.

Getting it done in Mumbai

The neurologist writes the requisition for both panels. We collect the blood sample at home or at the lab in Malad, and the hospital sends the spinal fluid after the lumbar puncture. Reports take over a week: the testing layers cell-based assays with confirmatory immunofluorescence.

Once the diagnosis is confirmed or strongly suspected, treatment starts with immune-calming therapies: high-dose steroids, IVIG, or plasma exchange, with stronger drugs like rituximab held in reserve. Any tumour found gets removed. Around four in five anti-NMDA patients recover within two years, though relapses happen in 10 to 25%, which is why follow-up continues long after discharge.

Three things to carry home. New psychosis or memory loss plus strange seizures deserves an immunity check, not just a psychiatry referral. Both samples matter, and the blood has to come before immune therapy. And a negative panel is not a closed door: the immune system does not always sign its work, but this panel is the best torch for finding the fingerprints.

Our Malad lab runs round the clock, routine reports in about 24 hours, and you can book the blood collection on 84250 40353. Start from the tests page and we will walk you through the exact samples your doctor ordered.

References

• Cleveland Clinic: Autoimmune Encephalitis (clinical/CME page)
• Mayo Clinic Laboratories: Encephalopathy, Autoimmune Evaluation (ENC2/ENS2 test catalog)
• Titulaer et al., Cleveland Clinic Journal of Medicine 2021: Autoimmune encephalitis review (peer-reviewed)
• NIH MedlinePlus: Autoimmune Encephalitis