Unusual case of anti-N-methyl-D-aspartic acid-receptor (NMDA-R) encephalitis and autoimmune polyglandular syndrome (APS)

Anti-N-Methyl-D-Aspartate Receptor Encephalitis with Serum Anti-Thyroid Antibodies: A Case Report and Literature Review

BACKGROUND Anti-N methyl D-aspartate receptor encephalitis (anti-NMDArE) is a disorder in which triggers such as infectious agents or neoplastic disease can lead to an autoimmune response against the nervous system, although this disorder is usually idiopathic. Some patients with anti-NMDArE have evidence of other autoimmune alterations. Here, we present a case of non-paraneoplastic anti-NMDArE with elevation of serum anti-thyroid antibodies and a literature review of this association. CASE REPORT A 16-year-old girl was admitted in the University Hospital of Bari for a new onset of tonic-clonic seizures. Progressively, the patient manifested also psychomotor agitation, language difficulties, memory impairment, psychotic symptoms, autonomic dysfunction, and psychomotor retardation. Blood evaluation revealed the presence of anti-thyroglobulin, anti-thyroperoxidase, and anti-NMDAr antibodies. Cerebrospinal fluid analysis confirmed the diagnosis of anti-NMDArE. No tumors were found. Treatment with intravenous immunoglobulin, steroids, and plasma exchange relieved symptoms and decreased levels of serum anti-NMDAr antibodies. After 12 months, the patient had full recovery of communicative capacity, with the persistence of slight difficulty of memory and mild tendency to irritability. Blood exams shown persistence of anti-NMDAr positivity and absence of anti-thyroid antibodies. CONCLUSIONS We report a rare case in which an autoimmune involvement of thyroid gland was concurrent with an anti-NMDArE. It would be useful for clinical practice to clarify whether the presence of anti-thyroid antibody an characterize the clinical course, prognosis, and response to treatment of the idiopathic type of anti-NMDArE.

Case of autoimmune polyendocrine syndrome type 3 complicated with anti-N-methyl-D-aspartic acid-receptor encephalitis

Anti-N-methyl-D-aspartate receptor (NMDA-R) encephalitis is an autoimmune disorder in which autoantibodies in the limbic system bind to GluN1 subunits of NMDA-Rs in the brain. We report a rare case of autoimmune polyendocrine syndrome type 3 complicated by anti-NMDA-R encephalitis. After hospitalization for type 1 diabetes, the 39-year-old patient developed various schizophreniform symptoms and seizures after cold-like symptoms. These findings are consistent with the diagnosis of anti-NMDA-R encephalitis. Immune-related encephalitis was suspected at the early phase of the disease, and cerebrospinal fluid was positive for anti-NMDA-R antibody. Early steroid pulse therapy was initiated during the disease course. The condition improved gradually to full recovery. Early detection and treatment of anti-NMDA-R encephalitis should enhance a positive outcome, considering that besides thyroid diseases and type 1 diabetes, various autoimmune diseases are associated with autoimmune polyendocrine syndrome type 3.

Association of thyroid peroxidase antibodies with anti-neuronal surface antibodies in health, depression and schizophrenia - Complementary linkage with somatic symptoms of major depression

Hashimoto's thyroiditis has been associated with major depression (MD) and schizophrenia (Sz) in epidemiological studies. However, diagnostically relevant antibodies (Abs) against thyroid peroxidase (TPO) and thyroglobulin (Tg) do not act directly on neurons. We hypothesized that an increased prevalence of anti-brain-Abs in thyroid-Ab-carriers could be linked with MD and Sz even without clinically manifest Hashimoto's thyroiditis. Serum samples from 638 acutely-ill patients with MD, Sz or matched controls were systematically screened for TPO- and Tg-Abs, other endocrine-Abs and a spectrum of specific anti-brain-Abs (directed against neuronal cell surface, synaptic, other neuronal or glial proteins). Analyses were based on indirect immunofluorescence in biochip mosaics of frozen tissue sections and transfected HEK293 cells expressing respective recombinant target antigens. Psychopathology was assessed on admission and after 6 weeks treatment by HAMD-21 (in MD) or PANSS (in Sz). Seroprevalence of TPO- and/or Tg-Abs was comparable in ill and healthy individuals (MD ~10%, Sz ~7%, controls ~9%) but thyroid-Abs were associated with neuronal cell surface/synaptic-Abs (p = 0.005), particularly in schizophrenia. Thyroid Ab-positive MD patients showed higher HAMD-21 scores (particularly somatic symptoms) at baseline (p = 0.026) and better reduction of symptoms after 6 weeks (p = 0.049) than thyroid-Ab-negative patients. This was unrelated to antidepressant drug dosage, thyroid hormonal-, inflammation- and anti-brain-Ab-status. No link with PANSS scores was observed in Sz. In conclusion, the co-occurrence of thyroid-Abs and neuronal surface/synaptic-Abs may be associated with Sz. Future cerebrospinal fluid research may be promising to clarify if thyroid-Ab-associated neuronal-Abs reach the brain in Sz patients. Thyroid-Ab-related differences regarding disease-severity and -course in MD are currently unexplained, but may be caused by un-identified anti-brain-Abs or a direct action of TPO-Abs on astrocytes.