Autoantibody profiles associated with clinical features in psychotic disorders

Prevalent and persistent new-onset autoantibodies in mild to severe COVID-19

Autoantibodies have been shown to be implied in COVID-19 but the emerging autoantibody repertoire remains largely unexplored. We investigated the new-onset autoantibody repertoire in 525 healthcare workers and hospitalized COVID-19 patients at five time points over a 16-month period in 2020 and 2021 using proteome-wide and targeted protein and peptide arrays. Our results show that prevalent new-onset autoantibodies against a wide range of antigens emerged following SARS-CoV-2 infection in relation to pre-infectious baseline samples and remained elevated for at least 12 months. We found an increased prevalence of new-onset autoantibodies after severe COVID-19 and demonstrated associations between distinct new-onset autoantibodies and neuropsychiatric symptoms post-COVID-19. Using epitope mapping, we determined the main epitopes of selected new-onset autoantibodies, validated them in independent cohorts of neuro-COVID and pre-pandemic healthy controls, and identified sequence similarities suggestive of molecular mimicry between main epitopes and the conserved fusion peptide of the SARS-CoV-2 Spike glycoprotein. Our work describes the complexity and dynamics of the autoantibody repertoire emerging with COVID-19 and supports the need for continued analysis of the new-onset autoantibody repertoire to elucidate the mechanisms of the post-COVID-19 condition.

Canadian Consensus Guidelines for the Diagnosis and Treatment of Autoimmune Encephalitis in Adults

Autoimmune encephalitis is increasingly recognized as a neurologic cause of acute mental status changes with similar prevalence to infectious encephalitis. Despite rising awareness, approaches to diagnosis remain inconsistent and evidence for optimal treatment is limited. The following Canadian guidelines represent a consensus and evidence (where available) based approach to both the diagnosis and treatment of adult patients with autoimmune encephalitis. The guidelines were developed using a modified RAND process and included input from specialists in autoimmune neurology, neuropsychiatry and infectious diseases. These guidelines are targeted at front line clinicians and were created to provide a pragmatic and practical approach to managing such patients in the acute setting.

Autoantibody Profiling and Anti-Kinesin Reactivity in ANCA-Associated Vasculitis

ANCA-associated vasculitides (AAV) are rare autoimmune diseases causing inflammation and damage to small blood vessels. New autoantibody biomarkers are needed to improve the diagnosis and treatment of AAV patients. In this study, we aimed to profile the autoantibody repertoire of AAV patients using in-house developed antigen arrays to identify previously unreported antibodies linked to the disease per se, clinical subgroups, or clinical activity. A total of 1743 protein fragments representing 1561 unique proteins were screened in 229 serum samples collected from 137 AAV patients at presentation, remission, and relapse. Additionally, serum samples from healthy individuals and patients with other type of vasculitis and autoimmune-inflammatory conditions were included to evaluate the specificity of the autoantibodies identified in AAV. Autoreactivity against members of the kinesin protein family were identified in AAV patients, healthy volunteers, and disease controls. Anti-KIF4A antibodies were significantly more prevalent in AAV. We also observed possible associations between anti-kinesin antibodies and clinically relevant features within AAV patients. Further verification studies will be needed to confirm these findings.

Autoantibodies against PIP4K2B and AKT3 Are Associated with Skin and Lung Fibrosis in Patients with Systemic Sclerosis

Systemic sclerosis (SSc) is a rare autoimmune systemic disease that leads to decreased survival and quality of life due to fibrosis, inflammation, and vascular damage in the skin and/or vital organs. Early diagnosis is crucial for clinical benefit in SSc patients. Our study aimed to identify autoantibodies in the plasma of SSc patients that are associated with fibrosis in SSc. Initially, we performed a proteome-wide screening on sample pools from SSc patients by untargeted autoantibody screening on a planar antigen array (including 42,000 antigens representing 18,000 unique proteins). The selection was complemented with proteins reported in the literature in the context of SSc. A targeted antigen bead array was then generated with protein fragments representing the selected proteins and used to screen 55 SSc plasma samples and 52 matched controls. We found eleven autoantibodies with a higher prevalence in SSc patients than in controls, eight of which bound to proteins associated with fibrosis. Combining these autoantibodies in a panel could lead to the subgrouping of SSc patients with fibrosis. Anti-Phosphatidylinositol-5-phosphate 4-kinase type 2 beta (PIP4K2B)- and anti-AKT Serine/Threonine Kinase 3 (AKT3)-antibodies should be further explored to confirm their association with skin and lung fibrosis in SSc patients.

Array-Based Multiplex and High-Throughput Serology Assays

The detection of antibody responses using serological tests provides means to diagnose infections, follow disease transmission, and monitor vaccination responses. The coronavirus disease 2019 (COVID-19) pandemic, caused by the SARS-CoV-2 virus, highlighted the need for rapid development of robust and reliable serological tests to follow disease spreading. Moreover, the rise of SARS-CoV-2 variants emphasized the need to monitor their transmission and prevalence in the population. For this reason, multiplex and flexible serological assays are needed to allow for rapid inclusion of antigens representing new variants as soon as they appear. In this chapter, we describe the generation and application of a multiplex serological test, based on bead array technology, to detect anti-SARS-CoV-2 antibodies in a high-throughput manner, using only a few microliters of sample. This method is currently expanding to include a multi-disease antigen panel that will allow parallel detection of antibodies towards several infectious agents.

Biomarkers of neurodegeneration in neural autoantibody-associated psychiatric syndromes: A retrospective cohort study

Background

Autoantibody-associated psychiatric syndromes are a novel disease entity that is not fully understood. Several lines of evidence suggest that neurodegenerative processes are involved here. We are investigating whether autoantibody-positive psychiatric syndromes differ from those that are autoantibody-negative in cerebrospinal fluid (CSF) neurodegeneration markers.

Methods

We retrospectively analyzed data from 167 psychiatric patients at the University Medical Center Göttingen from 2017 to 2020. We divided this patient cohort into two, namely antibody-positive and antibody-negative. We compared various clinical features, neurodegeneration markers, and their autoantibody status in CSF and serum. We then compared both cohorts' neurodegeneration markers to a representative Alzheimer cohort. We subdivided the patients into their diverse psychiatric syndromes according to the manual to assess and document psychopathology in psychiatry (the AMDP), and compared the neurodegeneration markers.

Results

Antibody-associated psychiatric syndromes do not appear to reveal significantly greater neurodegeneration than their antibody-negative psychiatric syndromes. 71% of antibody-positive patients fulfilled the criteria for a possible and 22% for a definitive autoimmune encephalitis. Our autoantibody-positive patient cohort's relative risk to develop an possible autoimmune encephalitis was 9%. We also noted that phosphorylated tau protein 181 (ptau 181) did not significantly differ between antibody-associated psychiatric syndromes and our Alzheimer cohort. The psycho-organic syndrome usually exhibits the most prominent neurodegeneration markers, both in antibody-positive and antibody-negative psychiatric patients.

Discussion

We did not find hints for neurodegenerative processes in our antibody-positive versus AD cohort considering total tau or amyloid markers. However, our findings indicate that the neurodegeneration marker ptau181 does not differ significantly between antibody-positive and Alzheimer cohorts, further suggesting axonal neurodegeneration in antibody-positive patients as AD patients have an elevated ptau181. The evidence we uncovered thus suggests that axonal neurodegeneration might affect patients suffering from autoantibody-associated psychiatric syndromes.

Antinuclear Antibodies and Thyroid Autoantibodies in the Serum of Chinese Patients with Acute Psychiatric Disorders: A Retrospective Study

Background

It has been shown that autoimmune diseases are associated with psychiatric disorders in epidemiological studies. The acute psychiatric disorder patients have higher frequency of autoantibodies in the blood, including antinuclear antibodies, anti-thyroid peroxidase, and thyroglobulin [thyroid antibody carriers]. However, large clinical studies with more relevant control groups in China are few.

Methods

This was a retrospective study. A total of 1669 sera were tested for autoantibodies in the clinical laboratory of the Fourth Affiliated Hospital, Zhejiang University School of Medicine from October 2016 to March 2021. All data available during this time period were analyzed. Only the first entry for each patient from inpatient care units was used for analysis. The clinical information and laboratory data of patients were retrospectively collected and analyzed.

Results

A significantly lower prevalence of antinuclear antibodies was observed in the healthy control group than in the patient group (21.7% vs 28.8%, P < .05). There was a significant difference in the prevalence of antinuclear antibodies between thyroglobulin-antibody carriers and thyroid peroxidase-antibody- and thyroglobulin-antibody-seronegative individuals in the unipolar depressive disorder group (P < .05). A positive anti-thyroid peroxidase test was significantly associated with patients having nonaffective psychoses (P < .05).

Conclusion

The results showed that psychiatric disorders were associated with antinuclear antibodies and thyroid autoantibodies in our large sample of patients admitted to acute psychiatric hospitalization, and autoimmune autoantibodies were potential biomarkers of psychotic disorders. The results might lead to new research directions for the study of psychiatric disorders in the future.

Immunopsychiatry – Innovative Technology to Characterize Disease Activity in Autoantibody-Associated Psychiatric Diseases

Background

Anti-neural autoantibody-associated psychiatric disease is a novel field in immunopsychiatry that has been attracting attention thanks to its potentially positive therapeutic outcome and distinct prognosis compared with non-organic psychiatric disease. This review aims to describe recent novel technological developments for improving diagnostics in the field of autoantibody-related psychiatric disease.

Methods

We screened for relevant articles in PubMed for this narrative article. We focused on research methods such as neuroimaging, immune cells and inflammation markers, and molecular biomarkers in human biofluids like serum and cerebrospinal fluid and plasma proteomics.

Results

We introduce several novel methods for investigating autoinflammation with the aim of optimizing therapies for autoantibody-associated psychiatric disease. We describe measuring the translocator protein 18kDa in activated microglia via positron emission tomography imaging, brain volumetric assessment, flow cell cytometry of cerebrospinal fluid and blood, and blood biological probes as well as psychopathological cues to help us gain insights into diagnosing inflammation and brain damage better in psychiatric patients presenting a suspected autoimmune etiology.

Conclusion

Our short methodological review provides an overview of recent developments in the field of autoantibody-related immunopsychiatry. More research is needed to prove their usefulness in diagnosing and treating autoantibody-associated psychiatric disease and its subtypes.

Psychopathology of psychiatric patients presenting autoantibodies against neuroglial antigens

BACKGROUND

Autoantibody-mediated psychiatric disorder is often difficult to diagnose as the clinical features of psychiatric disorder associated with neural autoantibodies are often similar. Thus, it is of major relevance to investigate whether psychopathology can differentiate between both disease entities as a biomarker and help us in searching for specific autoantibodies associated with psychiatric symptoms.

METHODS

We enrolled 154 patients of the Department of Psychiatry and Psychotherapy of the University Medical Center Göttingen with psychopathology data and retrospectively evaluated their patient records using the classification systems AMDP (Arbeitsgemeinschaft für Methodik und Dokumentation in der Psychiatrie) and HiTOP (Hierarchical Taxonomy of Psychopathology).

RESULTS

We identified 35 psychiatric patients revealing autoantibodies in their serum and/or cerebrospinal fluid (CSF) and 119 with no autoantibodies. Relying on the AMDP system, many more psychiatric patients with serum autoantibodies (51%) had problems with orientation than those without autoantibodies (32%) (p < 0.05). Furthermore, fewer psychiatric patients with serum autoantibodies exhibited a blunted affect (11.4 vs. 32.8%, p < 0.01) and affective rigidity (20 vs. 45%, p < 0.01). In particular, psychiatric patients presenting CSF autoantibodies (indicating an autoimmune symptomatic basis) experience more loss of vitality (5%) than those without autoantibodies (0%) (p < 0.05). Another interesting finding is that according to the AMDP classification, a manic syndrome is much more frequent in autoantibody-positive (8.6%) than autoantibody-negative psychiatric patients (0.8%) (p < 0.05). Another aspect is the more frequent occurrence of attention and memory deficits in patients with autoantibodies against intracellular targets compared with targets on the membrane surface.

CONCLUSION

Our findings indicate that neural autoantibodies in psychiatric patients could indicate a phenotype more often characterized by a manic syndrome, orientation disturbances within the cognitive spectrum, and fewer affect disturbances characterized by less blunted affect and not as seriously impaired feelings of vitality compared to controls. The novelty of our approach is the extensive autoantibody tests for various psychiatric syndromes in combination with a profound psychometric measurement with two different scales.