Neural antibody testing for autoimmune encephalitis: Impact of Autoimmune Neurology approval process on test utilization.

While neural antibody testing can be instrumental to diagnosing autoimmune encephalitis, concerns have been raised surrounding test overutilization [ 1 Budhram A. Dubey D. Sechi E. Flanagan E.P. Yang L. Bhayana V. et al. Neural antibody testing in patients with suspected autoimmune encephalitis. Clin. Chem. 2020; 66: 1496-1509 Crossref PubMed Scopus (27) Google Scholar , 2 Zidan A. Fein A. Zuchowski K. The use, misuse and abuse of paraneoplastic panels in neurological disorders. A retrospective study. Clin. Neurol. Neurosurg. 2019; 186105545 Crossref PubMed Scopus (7) Google Scholar , 3 Fredrich S.E. Vernino S. Blackburn K.M. Antibody testing for neurological autoimmune disorders: evaluation of best practices at a tertiary referral center. Front. Neurol. 2021; 12690415 Crossref PubMed Scopus (1) Google Scholar ]. In addition to placing strain on health care systems due to costliness, test overutilization can increase the proportion of false-positive antibody results and contribute to patient misdiagnosis [ 4 Budhram A. Yang L. Bhayana V. Mills J.R. Dubey D. Clinical sensitivity, specificity, and predictive value of neural antibody testing for autoimmune encephalitis. J. Appl. Lab. Med. 2022; 7: 350-356 Crossref PubMed Scopus (9) Google Scholar , 5 Flanagan E.P. Geschwind M.D. Lopez-Chiriboga A.S. Blackburn K.M. Turaga S. Binks S. et al. Autoimmune encephalitis misdiagnosis in adults. JAMA Neurol. 2023; 80: 30-39 Crossref PubMed Scopus (15) Google Scholar , 6 Dinoto A. Zara P. Mariotto S. Ferrari S. Flanagan E.P. Budhram A. et al. Autoimmune encephalitis misdiagnosis and mimics. J. Neuroimmunol. 2023; 378578071 Abstract Full Text Full Text PDF PubMed Scopus (1) Google Scholar ]. Despite these adverse impacts, no interventions aimed at improving utilization of neural antibody testing for autoimmune encephalitis have been examined. We developed an Autoimmune Neurology approval process for this testing to improve utilization at our centre, and herein examine test volume and yield following its implementation.