Anti-NMDAR Autoimmune Encephalitis: A Diagnostic Challenge in Clinical Laboratories

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is an antibody-mediated neurological disease which is acute, severe and with a complicated differential diagnosis. In 38% of cases, it arises as a paraneoplastic neurological syndrome (PNS) associated with cancer. Ovarian teratomas are the most frequently associated tumors, especially in young women. However, teratomas are usually mature and benign and psychiatric and neurological symptoms improve after resection. Clinical laboratories play a key role in the diagnosis and prognosis of these diseases, highlighting the importance of laboratory test results to prompt the search for the associated tumor. In addition, communication between laboratory medicine specialists and clinicians, as well as a multidisciplinary approach, are essential for early disease identification and treatment.