ARTICLE | doi:10.20944/preprints202209.0289.v1
Subject: Medicine & Pharmacology, Other Keywords: chronic fatigue syndrome; post-COVID syndrome; postural orthostatic tachycardia; microcirculation; immune system
Online: 20 September 2022 (03:37:00 CEST)
A Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating chronic disease of unknown aetiology under growing interest now in view of the increasingly recognized post-COVID syndrome as a new entity with similar clinical presentation. We performed the first cross-sectional study of ME/CFS in community population in Russia and then described and compared some clinical and pathophysiological characteristics of ME/CFS and post-COVID syndrome as neuroimmune disorders. Of the cohort of 76 individuals who suggested themselves suffering from ME/CFS 56 subsequently were confirmed as having CFS/ME according to ≥1 of the 4 most commonly used case definition. Of the cohort of 14 individuals with post-COVID-19 syndrome 14 met diagnostic criteria for ME/CFS. The prevalence of clinically expressed and subclinical anxiety and depression in ME / CFS and post-COVID ME/CFS did not differ significantly from that in healthy individuals. Severity of anxiety / depressive symptoms did not correlate with the severity of fatigue neigther in ME / CFS nor in post-COVID ME/CFS, but the positive correlation was found between the severity of fatigue and 20 other symptoms of ME / CFS related to the domains of “post-exertional exhaustion”, “immune dysfunction”, “sleep disturbances”, "dysfunction of the autonomic nervous system", "neurological sensory / motor disorders" and "pain syndromes". Immunological abnormalities were identified in 12/12 patients with ME / CFS according to the results of laboratory testing. The prevalence of postural orthostatic tachycardia assessed by the active standing test was 37.5% in ME / CFS and 75.0% in post-COVID ME/CFS (the latter was higher than in healthy controls, p = 0.02) There was a more pronounced increase in heart rate starting from the 6th minute of the test in post-COVID ME/CFS compared with the control group. Assessment of the functional characteristics of microcirculation by laser doppler flowmetry revealed obvious and very similar changes in ME/CFS and post-COVID ME/CFS compared to the healthy controls. The identified pattern corresponded to the hyperemic form of microcirculation disorders, usually observed in acute inflammatory processes or in deficiency of systemic vasoconstriction influences.
REVIEW | doi:10.20944/preprints202011.0147.v1
Subject: Medicine & Pharmacology, Allergology Keywords: antineuronal autoantibodies; autoimmune diseases; autoimmune encephalitis; food antigens; kynurenine pathway; microbiota; prolactin; cytokines; schizophrenia; stress
Online: 3 November 2020 (12:53:38 CET)
The review analyzes a possible role of autoimmune processes in the pathogenesis of schizophrenia and evolution of concepts on this issue from its origin to present. Risks of autoimmune processes causing schizophrenia are associated with several factors: an impaired functioning of dopaminergic and glutamatergic systems in the brain, kynurenine pathway disorder with overproduction of quinolinic, anthranilic and kynurenic acids (possibly altering both neurons and T-regulators), increased intestinal permeability, as well as food antigens’ effects, stress and infections with various pathogens at different stages of ontogenesis. An increase in the levels of proinflammatory cytokines and chemokines as well as a decrease in the levels of anti-inflammatory ones also may contribute to schizophrenia risks. Schizophrenia often occurs in those patients having various autoimmune diseases and their first-degree relatives. Cases of schizophrenia resulted from autoimmune pathogenesis (including autoimmune encephalitis caused by autoantibodies against various neuronal antigens) are characterized by quite severe cognitive and psychotic symptoms and less favorable prognosis. This severe course may result from the chronic immune damage of the neuronal receptors such as NMDA, GABA, and others and depend on hyperprolactinemia, induced by antipsychotics, but aggravating autoimmune processes [with 2 tables, 4 figures, bibliography: 99 references].
ARTICLE | doi:10.20944/preprints202207.0111.v1
Subject: Materials Science, Other Keywords: sarcoidosis; granulomatous diseases; vimentin; mutated vimentin; autoantibodies; autoimmunity
Online: 7 July 2022 (04:44:21 CEST)
There is a need to further characterize the antibody response to vimentin in relation to it possible involvement in pathogenicity of sarcoidosis, and other lung disorders. Objectives: We investigated serum samples from patients with sarcoidosis, healthy and diseased control subjects to evaluate levels and frequency of these antibodies. Materials and methods. A retrospective-prospective comparative study was performed in the years 2014-2017. 188 serum samples were examined for presence of autoantibodies to mutated citrullinated vimentin (anti-MCV). Patients with elevated anti-MCV levels were tested for antibodies to a cyclic citrullinated peptide (anti-CCP) and citrullinated vimentin (anti-Sa). Additionally, sera from 93 patients with sarcoidosis and 40 healthy subjects were evaluated for the presence of autoantibodies to non-modified vimentin. In all cases ELISA assays was used. The results were considered statistically significant at p-value less than 0.05. Results of the study. The high concentrations of anti-MCV. antibodies were more frequent in patients with sarcoidosis (40.9% of the cases, 38/93), compared to the control groups (23.6% and 25.0% of cases, respectively). In sarcoidosis, clinical symptoms similar to the autoimmune pathology were described. A moderate positive correlation between the anti-MCV and anti-Sa antibodies (r = 0.66) was found in 13 patients with sarcoidosis. There was no significant difference between the levels of the anti-MCV and the anti-CCP in patients with non-infectious lung diseases and the healthy control group. Conclusion. A high level of anti-MCV antibodies in patients with sarcoidosis characterizes the presence of an autoimmune process that is not related to citrullination. The absence of a significant difference in the level of antibodies to modifications of vimentin in patients with sarcoidosis may indicate the autoimmune process.