Are all antibody panels equal?

The discovery of autoantibodies to surface proteins mediating forms of autoimmune encephalitis was a pivotal moment in neurology. Most famously in the 2000s was the discovery of autoantibodies to the N-methyl-D-aspartate receptor (NMDAR).1 The recognition of this and other antibodies has not only facilitated characterisation, diagnosis and effective treatment of autoimmune encephalitis but has fuelled a paradigm shift in how central nervous system (CNS) (auto)immunity is viewed.2 Now, there are over 20 distinct forms of autoimmune encephalitis associated with neuronal surface antibodies, and across its varied forms in developed nations, autoimmune encephalitis is probably as prevalent as infective encephalitis.3 Although medical management has many similarities across sub-types, there are key differences encompassing immunotherapy selection and duration, prognostic factors including likelihood of seizure freedom following autoimmune encephalitis, and rate and type of associated malignancies.4 5 Therefore, as the number of autoimmune encephalitides grows, the availability and accuracy of testing and interpretation of the results become increasingly important.