Paraneoplastic syndrome-associated neuronal antibodies in adult ADHD

Autoantibody-associated psychiatric symptoms and syndromes in adults: A narrative review and proposed diagnostic approach

Background

Autoimmune-mediated encephalitis is a disease that often encompasses psychiatric symptoms as its first clinical manifestation’s predominant and isolated characteristic. Novel guidelines even distinguish autoimmune psychosis from autoimmune encephalitis. The aim of this review is thus to explore whether a wide range of psychiatric symptoms and syndromes are associated or correlate with autoantibodies.

Methods

We conducted a PubMed search to identify appropriate articles concerning serum and/or cerebrospinal fluid (CSF) autoantibodies associated with psychiatric symptoms and syndromes between 2000 and 2020. Relying on this data, we developed a diagnostic approach to optimize the detection of autoantibodies in psychiatric patients, potentially leading to the approval of an immunotherapy.

Results

We detected 10 major psychiatric symptoms and syndromes often reported to be associated with serum and/or CSF autoantibodies comprising altered consciousness, disorientation, memory impairment, obsessive-compulsive behavior, psychosis, catatonia, mood dysfunction, anxiety, behavioral abnormalities (autism, hyperkinetic), and sleeping dysfunction. The following psychiatric diagnoses were associated with serum and/or CSF autoantibodies: psychosis and schizophrenia spectrum disorders, mood disorders, minor and major neurocognitive impairment, obsessive-compulsive disorder, autism spectrum disorders (ASD), attention deficit hyperactivity disorder (ADHD), anxiety disorders, eating disorders and addiction. By relying on these symptom clusters and diagnoses in terms of onset and their duration, we classified a subacute or subchronic psychiatric syndrome in patients that should be screened for autoantibodies. We propose further diagnostics entailing CSF analysis, electroencephalography and magnetic resonance imaging of the brain. Exploiting these technologies enables standardized and accurate diagnosis of autoantibody-associated psychiatric symptoms and syndromes to deliver early immunotherapy.

Conclusions

We have developed a clinical diagnostic pathway for classifying subgroups of psychiatric patients whose psychiatric symptoms indicate a suspected autoimmune origin.

•

Autoantibodies are associated with a broad spectrum of psychiatric syndromes.

•

More systematic studies are needed to elucidate the significance of autoantibodies.

•

We developed a pathway to identify autoantibody-associated psychiatric syndromes.

The clinical significance of atypical indirect immunofluorescence patterns on primate cerebellum in paraneoplastic antibody screening

Purpose

Screening for paraneoplastic antibodies is often performed by means of indirect immunofluorescence on primate cerebellar slices. However, atypical immunofluorescence patterns, i.e. patterns that are not specifically related to paraneoplastic antibodies, are often reported. The clinical significance of these patterns is not clear. Therefore, the purpose of this study was to determine the significance and diagnostic value—in terms of a paraneoplastic neurological syndrome or other neurological disease being diagnosed in the patient—of such atypical immunofluorescence screening patterns on primate cerebellum.

Methods

This study is a retrospective single center study including atypical indirect immunofluorescence screening patterns of patients with a negative or absent typing assay for intraneuronal and anti-amphiphysin paraneoplastic antibodies. Patients with a positive typing assay or without final diagnosis were excluded. Included patients were grouped according to (i) reported immunofluorescence pattern and (ii) established diagnosis, after which contingency table analyses were performed to investigate an interrelation between reported pattern and diagnostic group.

Results

In 3.7% of cases, patients with an atypical pattern obtained a final diagnosis of a paraneoplastic neurological syndrome. The presence of atypical patterns was more prominent in patients with epilepsy or peripheral neuropathies (p_{Monte Carlo simulation}= 0.026), without, however, adding any diagnostic information.

Conclusions

An atypical indirect immunofluorescence pattern on primate cerebellum in the screening for paraneoplastic antibodies has only very minor relevance with respect to paraneoplastic neurological syndromes or any other neurological disease, recommending clinicians to interpret the results of positive screening assays for such antibodies with care.

Electronic supplementary material

The online version of this article (10.1186/s13317-019-0116-6) contains supplementary material, which is available to authorized users.

What is the significance of onconeural antibodies for psychiatric symptomatology? A systematic review

BACKGROUND

Patients with intracellular onconeural antibodies may present with neuro-psychiatric syndromes. We aimed to evaluate the evidence for an association between well-characterized onconeural antibodies and psychiatric symptoms in patients with and without paraneoplastic central nervous system syndromes.

METHODS

Eligible studies were selected from 1980 until February 2017 according to standardized review criteria and evaluated using Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2). We included studies describing the psychiatric symptomatology of onconeural antibody positive patients and the prevalence of onconeural antibodies in patients with psychiatric disorders.

RESULTS

Twenty-seven studies met the inclusion criteria. Six studies reported on the prevalence of well-characterized onconeural antibodies in patients with different psychiatric disorders, ranging from 0% to 4.9%. Antibody prevalence in controls was available from three studies, ranging from 0% to 2.8%. Data heterogeneity precluded a meta-analysis. Two cerebrospinal fluid studies found well-characterized onconeural antibodies in 3.5% and 0% of patients with psychotic and depressive syndromes, respectively.

CONCLUSIONS

The available evidence suggests that the prevalence of well-characterized onconeural antibodies in patients with psychiatric disorders is generally low. However, the question whether onconeural antibodies are important in select patients with a purely psychiatric phenotype needs to be addressed by appropriately designed studies in the future.