Thread by @CroakeyNews

First keynote is by Prof Belinda Lennox @BLennox4, from University of Oxford, speaking about 'autoimmune psychosis-current state of play' #RANZCP2022

Schizophrenia/psychosis is a brain disorder, with neurological as well as psychiatric symptoms. The question being discussed is what evidence is there that some psychosis is autoimmune - @BLennox4 #RANZCP2022

Have diagnostic criteria and therapies - but not as much as known about the cause of psychosis - @BLennox4 #RANZCP2022

Why would it be a reasonable hypothesis that a proportion of psychosis is autoimmune? Some clues - some genes associated with schizophrenia are also associated with the immune system - @BLennox4 #RANZCP2022

Epidemiological data indicates increased autoimmune disease, such as Graves' disease or T2DM, in those with schizophrenia - @BLennox4 #RANZCP2022

Other research has found increased schizophrenia in those with autoimmune disease and infection - @BLennox4 #RANZCP2022

Also standing out is a lack of association between rheumatoid arthritis and people with schizophrenia - more research required to investigate why - @BLennox4 #RANZCP2022

Fascinating clues, but not helpful in clinical practice yet - @BLennox4 #RANZCP2022

Game changer was the discovery of antibodies as
pathogenic treatable cause of encephalitis - @BLennox4 #RANZCP2022

To identify NMDA-receptor- test using cell-based assays for the particular antigen interested in, and place patient sample on top of that cell. If patient cells stick on top of cell, than fairly good indication of NMDA receptor - @BLennox4 #RANZCP2022

NMDA-receptor encephalitis is a disorder mostly seen in teenage females, rare, rapidly progressing & neurological, where most patients present to psychiatrists initially (with psychosis, personality change, often abrupt) - @BLennox4 #RANZCP2022

Cognitive dysfunction in patients presenting with NMDA-receptor are broad. In 1-3 weeks, the disorder progresses, incl autonomic and movement disruptions - @BLennox4 #RANZCP2022

Diagnosis of NMDA-receptor encephalitis difficult - the only way is to find the antibodies in the CSF and signs of inflammation. Patients tend to have normal MRIs, blood markers - @BLennox4 #RANZCP2022

Treatment - must be treated quickly and aggressively, plasma exchange, high-dose steroids, monoclonal antibody, "proper heavy duty treatment to save a life in this disorder"..But, there has never been a clinical trial in this disorder- @BLennox4 #RANZCP2022

To bring it back to psychiatry, the NMDA-receptor finding was incredibly relevant to schizophrenia - @BLennox4 #RANZCP2022

Recommended book by Susannah Cahalan, 'Brain on Fire: My month of madness,' one of the first persons to be diagnosed with NMDA-receptor encephalitis. Treated by plasma exchange - @BLennox4 #RANZCP2022

NMDA dysfunction as a model for schizophrenia, research findings 👇 showing associations with NMDA receptors - @BLennox4 #RANZCP2022

Psychiatric symptoms in NMDA receptor encephalitis = prominent mood disturbance, catatonia, behavioural disturbance, most patients had a mix of all symptoms - @BLennox4 #RANZCP2022

Message to clinicians- you can't pick out NMDA receptor encephalitis in patients by symptom checks - @BLennox4 #RANZCP2022

Lumbar puncture needed for diagnosis of NMDA receptor encephalitis to identify antibodies in CSF - @BLennox4 #RANZCP2022

Red flag symptoms for NMDA receptor encephalitis= catatonia, adverse response to anti-psychotics, decreased level of consciousness, patient with autonomic dysfunction - @BLennox4 #RANZCP2022

Could the same antibodies be responsible for some cases of schizophrenia (that don't have the red flag symptoms)? - @BLennox4 #RANZCP2022

Some of the research @BLennox4 talks about...
'Prevalence and clinical characteristics of serum neuronal cell surface antibodies in first-episode psychosis: a case-control study' - Lennox et al. 2016 #RANZCP2022
thelancet.com/journals/lanps…

'Influence of methodological and patient factors on serum NMDAR IgG antibody detection in psychotic disorders: a meta-analysis of cross-sectional and case-control studies' - Cullen et al. 2021 #RANZCP2022
thelancet.com/journals/lanps…

Million dollar question - so what?
Do patients with schizophrenia and NMDAR antibodies get better with immunotherapy in the same way as those with encephalitis? - @BLennox4 #RANZCP2022

Some investigations have found that not everybody with serum-antibody has CSF-antibody - @BLennox4 #RANZCP2022

In @BLennox4 clinical service, they offer clients immunotherapy as trial. Information about sinapps.org.uk below. #RANZCP2022
psych.ox.ac.uk/research/autoi…

What next? Higher level of proof needed. Challenges incl working in de-medicalised community services, we don't do lumbar punctures etc. - @BLennox4 #RANZCP2022