• About
  • Keywords

Toxoplasma gondii & Human Phenotype

Compendium of Known Effects and Ongoing Research

tryptophan

Latent toxoplasmosis and psychiatric symptoms – A role of tryptophan metabolism?

January 31, 2020
Latent toxoplasmosis and psychiatric symptoms - A role of tryptophan metabolism?
Journal of Psychiatric Research 2019, 110: 45 - 50
Click for abstract
Toxoplasma gondii (TOX) is a common parasite which infects approximately one third of the human population. In recent years, it has been suggested that latent toxoplasmosis may be a risk factor for the development of mental disorders, particularly schizophrenia and anxiety. With regards to depression the results have been varied. The main objective of this study was to examine subpopulations from the Danish PRISME and GENDEP populations for TOX IgG antibodies. These consisted of: a group with symptoms of anxiety, a group suffering from burnout syndrome, as well as two different subpopulations with depression of differing severity. The secondary objective of this study was to examine whether tryptophan metabolism was altered in TOX-positive subjects within each subpopulation. Our results show that the anxiety and burnout populations were more likely to be TOX IgG seropositive. Furthermore, we find that the moderate-severe but not mild-moderate depressive subpopulation were associated with TOX seropositivety, suggesting a possible role of symptom severity. Additionally, we found that TOX positive subjects in the anxiety and burnout subpopulations had altered tryptophan metabolism. This relationship did not exist in the mild-moderate depressive subpopulation. These results suggest that TOX seropositivity may be related to anxiety, burnout and potentially to severity of depression. We furthermore show that the psychiatric symptoms could be associated with an altered tryptophan metabolism.

Tagged: 3 ioxygenasepattern, antidepressant, anxiety, burnoutdepression, common mental- disorders, depression reistant, gondii infection, indoleamine 2, kynurenine, pathway, Toxoplsma gondii, tryptophan

Mental health

Toxoplasma gondii seropositivity and suicide rates in women

October 19, 2011
Ling, V. J., Lester, D., Mortensen, P. B., Langenberg, P. W., Postolache, T. T.
Journal of Nervous and Mental Disease 2011; 199: 440-444
Click for abstract
Toxoplasma gondii (T. gondii) is an intracellular protozoan parasite that infects roughly a third of the world population. In an immunocompetent host, infection is generally chronic and asymptomatic, as the immune system keeps T. gondii confined to cysts and the intracellular space within the muscle and brain. Seropositivity has been linked to schizophrenia, car accidents, changes in personality, and more recently, suicidal attempts. Very recently, seroprevalence for 20 European countries was found to be associated with increased suicide rates. Although suicide rates were age-standardized, given that T. gondii seroprevalence increases with age and that the blood samples were drawn in women, we now retested in women only the association between suicide and T. gondii seropositivity, stratified by age. Simple correlations between ranked T. gondii seropositivity and suicide rate identified statistically significant relationships in women 60 years or older (p < 0.05); adjusting for GDP, the statistical significance expanded to include women 45 years and older. The strongest association was in the 60- to 74-year-old group where, after adjustment for GDP, the relationship (p = 0.007) resisted Bonferroni adjustment for multiple comparisons. In conclusion, the results suggest that a positive relationship between rates of infection with T. gondii and suicide is apparent in women of postmenopausal age. Prospective studies are necessary to further confirm this association predictively and to explore mechanisms mediating this relationship.

Tagged: behavior, brain, cat, depletion, depression, europe, infection, latent toxoplasmosis, risk, suicide, Toxoplasma gondii, toxoplasmosis, traffic accidents, tryptophan

BehaviorMental health

Association between intracellular infectious agents

October 19, 2010
Krause, D., Matz, J., Weidinger, E., Wagner, J., Wildenauer, A., Obermeier, M., Riedel, M., Muller, N.
European Archives of Psychiatry and Clinical Neuroscience 2010; 260: 359-363
Click for abstract
The underlying pathophysiological mechanisms in Tourette's syndrome (TS) are still unclear. Increasing evidence supports the involvement of infections, possibly on the basis of an altered immune status. Not only streptococci but also other infectious agents may be involved. This study investigates the association between the neurotrophic agents Chlamydia, Toxoplasma and TS. 32 patients with TS and 30 healthy matched controls were included. For each individual, IgA/IgG antibody titers against Chlamydia trachomatis/pneumoniae and Toxoplasma gondii were evaluated and analyzed with Fisher's exact test. We found a significantly higher rate of TS patients with elevated antibody titers against Chlamydia trachomatis (P = 0.017) as compared to controls. A trend toward a higher prevalence in the Tourette's group was shown for Toxoplasma (P = 0.069). In conclusion, within the TS patients a higher rate of antibody titers could be demonstrated, pointing to a possible role of Chlamydia and Toxoplasma in the pathogenesis of tic disorders. Because none of these agents has been linked with TS to date, a hypothesis is that infections could contribute to TS by triggering an immune response. It still remains unclear whether tic symptoms are partly due to the infection or to changes in the immune balance caused by an infection.

Tagged: chlamydia trachomatis, disease, immune system, infections, mycoplasma-pneumoniae infection, obsessive-compulsive disorder, pandas, plasma kynurenine, Schizophrenia, tic disorder, tourette's syndrome, Toxoplasma gondii, tryptophan, united-states

Mental health

Autism spectrum disorders may be due to cerebral toxoplasmosis associated with chronic neuroinflammation causing persistent hypercytokinemia that resulted in an increased lipid peroxidation, oxidative stress, and depressed metabolism of endogenous and exogenous substances

October 19, 2010
Prandota J.
Research in Autism Spectrum Disorders 2010; 4: 119-155
Click for abstract
Worldwide, approximately 2 billion people are chronically infected with Toxoplasma gondii with largely yet unknown consequences. Patients with autism spectrum disorders (ASD) similarly as mice with chronic toxoplasmosis have persistent neuroinflammation, hypercytokinemia with hypermetabolism associated with enhanced lipid peroxidation, and extreme changes in the weight resulting in obesity or wasting. Data presented in this review suggest that environmental triggering factors such as pregnancy, viral/bacterial infections, vaccinations, medications, and other substances caused reactivation of latent cerebral toxoplasmosis because of changes in intensity of latent central nervous system T. gondii infection/inflammation and finally resulted in development of ASD. Examples of such environmental factors together with their respective biomarker abnormalities are: pregnancy (increased NO, IL-1 beta, TNF-alpha, IL-6, IL-10, prolactin: decreased IFN-gamma, IL-12), neuroborreliosis (increased IL-1 beta, sIL-1R2, TNF-alpha, IFN-gamma, IL-6, IL-10, IL-12, IL-18, transforming growth factor-beta 1 (TGF-beta 1)), vital infections (increased IL-1 beta, IL-6, IL-8, TNF-alpha, IFN-gamma/alpha/beta,TGF-beta 1), thimerosal (increased IL-5, IL-13; decreased IFN-gamma,TNF-alpha,IL-6, IL-12p70, NOS), and valproic acid (increased NO, reactive oxygen species; decreased TNF-alpha, IL-6, IFN-gamma). The imbalances in pro- and antiinflammatory processes could markedly hinder [lost defense mechanisms important for immune control of the parasite, such as the production of NO, cytokines, and reactive oxygen/nitrogen species, tryptophan degradation by indoleamine 2,3-dioxygenase and/or tryptophan 2,3-dioxygenase, limitation of the availability of intracellular iron to T gondii, and the mechanisms mediated by an IFN-gamma responsive gene family. These fluctuations could result in a recurrent profuse multiplication of T. gondii in the brain associated with persistent neuroinflammation, chronic overproduction of pro- and antiinflammatory cytokines, and NO causing increased oxidative stress, and significantly depressed activity of several enzymes including cytochrome P450 monooxygenase family responsible for metabolism of physiological substrates and xenobiotics, such as steroids, fatty acids, prostaglandins, drugs, pollutants, and carcinogens, finally leading to development of ASD. This reasoning may be supported by such abnormal metabolic events as: (1) patients with ASD have significantly decreased melatonin levels caused by marked deficit in acetylserotonin methyltransferase activity, possibly resulting from maternal and/or fetal/postnatal overproduction of NO, characteristic for this clinical entity; (2) thimerosal inhibited both insulin-like growth factor-1- and dopamine-stimulated methylation reactions, and depressed methionine synthase activity, the metabolic events important for promoting normal neurodevelopment; (3) valproic acid, a strong histone deacetylase inhibitor, have potent anti-T. gondii activity. Thus, patients with ASD should be tested for T. gondii infection. (C) 2009 Elsevier Ltd. All rights reserved

Tagged: abnormalities, abnormality, acid, acids, aktivity, autism, autistic spectrum disorders, availability, beta, biomarker, brain, cell-mediated-immunity, central-nervous-system, cerebral, Cerebral toxoplasmosis, change, changes, chronic, chronic neuroinflammation, chronic toxoplasmosis, clinical, congenital cytomegalovirus-infection, consequence, consequences, control, could, cytochrome, cytochrome p450, cytokine, cytokines, data, defense, defense-mechanisms, deficit, degradation, depressed enzyme activities, development, disorder, disorders, drug, drugs, environmental, environmental factors, enzyme, enzymes, event, events, example, families, family, fluctuation, fluctuations, gene, gene families, gene family, gondii, gondii infection, growth, growth-factor-beta, hepatic drug-metabolism, herpes-simplex-virus, histone, histone deacetylase, hypercytokinemia, hypermetabolic state, il-1, il-10, il-12, il-13, il-6, immune, immune irregularities, important, infection, infections, inhibitor, insulin-like, intensity, interferon-inducing agents, intracellular, iron, latent, level, limitation, lipid, lipid-peroxidation, maternal, mechanism, mechanisms, medication, melatonin, metabolism, methionine, methylation, methyltransferase, methyltransferase aktivity, mice, multiplication, nervous, nervous system, neurodevelopment, nf-kappa-b, nitric oxide, nitric-oxide synthase, obesity, or, overproduction, oxidative stress, oxygen, p-450-dependent monooxygenase systems, Parasite, patient, patients, people, persistent, pregnancies, pregnancy, proces, prolactin, prostaglandins, reaction, reactivation, review, species, spectrum, spectrum disorders, spektra, steroids, stress, substrate, systém, t, tgf-beta, tnf-alpha, Toxoplasma, Toxoplasma gondii, toxoplasmosis, tryptophan, tumor-necrosis-factor, vaccination, vital, weight, xenobiotics

Mental health

A controlled prospective study of Toxoplasma gondii infection in individuals with schizophrenia: Beyond seroprevalence

October 27, 2007
Hinze-Selch, D., Daubener, W., Eggert, L., Erdag, S., Stoltenberg, R., Wilms, S.
Schizophrenia Bulletin 2007; 33: 782-788.
Click for abstract
Toxoplasma gondii (TG) infection has been reported to be more frequent in schizophrenia. The interaction of the lifelong persisting parasite with the host's immune system involves T-cell/interferon-gamma-induced degradation of tryptophan and provides a challenge to the host well beyond a possible role in the etiology of schizophrenia. The hypothesis we tested in this study was that TG infection may be more frequent (serofrequency) and/or more intense (serointensity) in patients with schizophrenia or major depression compared with psychiatrically healthy controls. In addition, these measures are associated with the clinical course. We did a cross-sectional, prospective investigation of individuals with schizophrenia (n = 277) and major depression (n = 465) admitted to our department (2002-2005) and of healthy controls (n = 214), with all groups adjusted for age and geographic home region. Serofrequency was comparable between the groups, but serointensity was significantly higher in the patients. In individuals with schizophrenia, serointensity was significantly positively associated with C-reactive protein levels and leukocyte counts, and first-episode patients yielded significantly higher serotiters. Immunomodulatory medication was associated with decreased serotiters. In addition, the route of infection appears to differ between patients and controls. Thus, our results support increased host responses to TG infection in the patients, as well as increased titers in first-episode patients with schizophrenia; this may relate to the shifted T-helper 1/2 status described in these patients. Therefore, we suggest that TG infection, particularly in individuals with schizophrenia, is an important environmental factor in the interaction between psychiatric vulnerability, genetic background, immunomodulation, and the neurotransmitter systems.

Tagged: 2, 3-dioxygenase, activation, antibodies, astrocytes, cells, depression, frontal-cortex, immune, immunity, infection, nitric-oxide synthase, psychosis, Toxoplasma gondii, tryptophan, tryptophan depletion

Mental health

Topics

  • Behavior 105
  • Cognitive functions 64
  • Mental health 439
  • Morphology 6
  • Motor functions 10
  • Personality 36
  • Physical health 134
  • Reproduction 36
  • Reviews 40
  • Sensory functions 3
  • Uncategorized 2

Archives

Recent articles

  • Mortality Patterns of Toxoplasmosis and Its Comorbidities in Tanzania: A 10-Year Retrospective Hospital-Based Survey February 6, 2020
  • The role of latent toxoplasmosis in the aetiopathogenesis of schizophrenia–the risk factor or an indication of a contact with cat? February 6, 2020
  • The Association between Toxoplasma gondii Infection and Risk of Parkinson’s Disease: A Systematic Review and Meta-Analysis February 6, 2020

Recent Comments

    Meta

    • Log in
    • Entries feed
    • Comments feed
    • WordPress.org

    Copyright © 2023 Toxoplasma gondii & Human Phenotype.

    ToxoBehavior WordPress Theme by Jelena Braum