Anti-N-Methyl-D-Aspartate Receptor Encephalitis Presenting as Acute Psychosis in a Renal Transplant Recipient Under Chronic Immunosuppression
Year: 2026
Type: article
Study design: Case Report
Abstract: Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is the most frequent autoimmune encephalitis and characteristically debuts with psychiatric symptoms, which delays etiologic diagnosis. Its occurrence in patients immunosuppressed by post-transplant therapy is exceptional, with fewer than ten reported cases, most of them with unfavorable outcomes. We describe a 38-year-old woman with a 13-year-old renal graft and stage 4 chronic kidney disease, maintained on tacrolimus and mycophenolate, who was admitted to an acute psychiatric unit with abrupt-onset psychosis comprising mystical-megalomanic delusions, auditory hallucinations, and severe psychomotor agitation. Three weeks later, productive symptoms ceased abruptly and a rigid-akinetic syndrome emerged, accompanied by fever, autonomic instability, and bilateral mydriasis. Because rigidity and mutism followed an increase in aripiprazole dosage, neuroleptic malignant syndrome was initially suspected; mydriasis, characteristically absent in that condition, together with persistence of the neurological syndrome after antipsychotic withdrawal, redirected the diagnosis. Cerebrospinal fluid showed mononuclear pleocytosis and elevated protein, and anti-GluN1 antibodies were positive in serum and cerebrospinal fluid. Sequential immunotherapy with intravenous methylprednisolone, immunoglobulin, and plasmapheresis was administered, and exploratory oophorectomy revealed no teratoma. The patient achieved near-complete functional recovery, with only mild residual attentional impairment at 14 months. This case illustrates the diagnostic overlap between autoimmune encephalitis and primary psychotic disorders at first psychiatric contact, identifies pupillary dilation as a clinically useful discriminating sign against neuroleptic malignant syndrome, and documents a favorable outcome in a setting where previously published post-transplant cases have fared poorly.
Source: Psychopharmacology Bulletin
DOI: 10.64719/pb.21633
Institution: Marqués de Valdecilla University Hospital
Language: English
Subfield: Clinical Neurology
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W7225194109