Infection and thyroid autoimmunity: A seroepidemiologic study of TPOaAb

Molecular Mechanisms in Autoimmune Thyroid Disease

The most common cause of acquired thyroid dysfunction is autoimmune thyroid disease, which is an organ-specific autoimmune disease with two presentation phenotypes: hyperthyroidism (Graves-Basedow disease) and hypothyroidism (Hashimoto’s thyroiditis). Hashimoto’s thyroiditis is distinguished by the presence of autoantibodies against thyroid peroxidase and thyroglobulin. Meanwhile, autoantibodies against the TSH receptor have been found in Graves-Basedow disease. Numerous susceptibility genes, as well as epigenetic and environmental factors, contribute to the pathogenesis of both diseases. This review summarizes the most common genetic, epigenetic, and environmental mechanisms involved in autoimmune thyroid disease.

Pancreatic Pathological Changes in Murine Toxoplasmosis and Possible Association with Diabetes Mellitus

BACKGROUND

Previous studies have reported involvement of Toxoplasma gondii (T. gondii) infections in the pathogenesis of some autoimmune diseases, such as polymyositis, rheumatoid arthritis, autoimmune thyroiditis, and Crohn's disease. However, data on the association between T. gondii infections and Type 1 diabetes mellitus (T1DM) are still controversial. Therefore, in the present study, we aimed to investigate the pancreatic pathological changes in mouse models with acute and chronic toxoplasmosis and their association with T1DM.

MATERIALS AND METHODS

Three groups (10 mice each) of male Swiss Albino mice were used. One group of mice was left uninfected, whereas the second and third groups were infected with the acute virulent T. gondii RH strain and the chronic less virulent Me49 T. gondii strain, respectively. T. gondii-induced pancreatic pathological changes were evaluated by histopathological examination of pancreatic tissues. Moreover, the expression of insulin, levels of caspase-3, and the pancreatic infiltration of CD8⁺ T cells were evaluated using immunohistochemical staining.

RESULTS

Pancreatic tissues of T. gondii-infected animals showed significant pathological alterations and variable degrees of insulitis. Mice with acute toxoplasmosis exhibited marked enlargement and reduced numbers of islets of Langerhans. However, mice with chronic toxoplasmosis showed considerable reduction in size and number of islets of Langerhans. Moreover, insulin staining revealed significant reduction in β cell numbers, whereas caspase-3 staining showed induced apoptosis in islets of Langerhans of acute toxoplasmosis and chronic toxoplasmosis mice compared to uninfected mice. We detected infiltration of CD8⁺ T cells only in islets of Langerhans of mice with chronic toxoplasmosis.

CONCLUSIONS

Acute and chronic toxoplasmosis mice displayed marked pancreatic pathological changes with reduced numbers of islets of Langerhans and insulin-producing-β cells. Since damage of β cells of islets of Langerhans is associated with the development of T1DM, our findings may support a link between T. gondii infections and the development of T1DM.

Does latent Toxoplasma infection have a protective effect against developing multiple sclerosis? Evidence from an updated meta-analysis

Previous epidemiologic evidence suggests a protective effect of Toxoplasma gondii infection against multiple sclerosis (MS) development; however, inconsistent findings have been reported in this regard. Therefore, we performed an updated meta-analysis of observational studies to investigate the association of To. gondii infection with MS development. We searched all articles published in PubMed, Scopus, Embase and Web of Science databases as of 20 December 2021. A random effects meta-analysis model was used to generate the pooled OR at 95% CIs. The heterogeneity between studies was assessed using I2 and Cochran's Q statistics. Moreover, the likelihood of publication bias was determined by Egger's regression test. A total of 11 studies were eligible for meta-analysis, including 1172 MS cases and 1802 controls. Our findings indicated that 29.8% (95% CI 22.8 to 37.2%) of MS patients were seropositive for To. gondii infection, compared with 34.2% (95% CI 21.9 to 47.6%) of control subjects. The estimated pooled OR was 0.79 (95% CI 0.49 to 1.26), suggesting a non-significant negative association between To. gondii infection and MS development (p>0.05). The current study does not support the significant protective role of To. gondii infection on MS development. Our findings imply that further well-designed epidemiological and mechanistic studies are warranted to ascertain the possible association between To. gondii infection and MS and to exclude the potential confounders.

Association between Toxoplasma gondii infection and thyroid dysfunction: a case-control seroprevalence study

Background

The association between Toxoplasma gondii infection and thyroid disease has been poorly studied. Therefore, we sought to determine the association between T. gondii seropositivity and thyroid dysfunction.

Methods

We performed an age- and gender-matched case-control study of 176 patients suffering from hypothyroidism (n = 161) or hyperthyroidism (n = 15) and 528 control subjects without these diseases in a public hospital in Durango City, Mexico. Anti-Toxoplasma IgG antibodies were determined in sera from cases and controls using a commercially available enzyme-linked immunoassay.

Results

Anti-T. gondii IgG antibodies were found in 11 (6.3%) of 176 patients suffering from thyroid dysfunction and in 48 (9.1%) of 528 control subjects (OR = 0.66; 95% CI: 0.33–1.31; P = 0.23). Stratification by two groups of age (50 years and younger, and 51 year and older) showed that the youngest group of patients with thyroid dysfunction had a significantly lower seroprevalence of T. gondii infection than its age- and gender-matched control group (1/83: 1.2% vs 23/257: 8.6%; OR = 0.12; 95% CI: 0.01–0.93; P = 0.01). This stratification also showed that the youngest group of patients with hypothyroidism had a significantly lower seroprevalence of T. gondii infection than its age- and gender matched control group (0/75: 0% vs 21/233: 9.0%; P = 0.003).

Conclusions

Our results suggest that thyroid dysfunction is not associated with seropositivity to T. gondii in general; however, in young (50 years or less) patients, a negative association between infection and thyroid dysfunction and hypothyroidism was found. Further research to confirm this negative association is needed.

An updated literature review on maternal-fetal and reproductive disorders of Toxoplasma gondii infection

BACKGROUND

Toxoplasma gondii infection is one of the most prevalent infectious disease with worldwide distribution. Congenital toxoplasmosis is annually responsible for 1.20 million disability-adjusted life years around the world, but often it is overlooked many countries.

METHODS

We performed an updated review to summarize the current researches on fetal, neonatal and maternal consequences of T. gondii infection and also adverse effects of toxoplasmosis on women reproductive organs.

RESULTS

T. gondii infection could be cause of several abnormalities from hydrocephalus, microcephaly, deafness, abortion and still birth in fetal to psychomotor retardation, intellectual disability, hearing loss, slower postnatal motor development during the first year of life; and chorioretinitis, cryptogenic epilepsy and autism spectrum disorders in newborns. Moreover, this infection is related with neuropsychiatric disorders such as anxiety, schizophrenia spectrum disorders, depression, decreased weight, autoimmune thyroid diseases, self-directed violence, violent suicide attempts in mothers. This literature review emphasized that toxoplasmosis could be an important neglected factor endometritis, ovarian dysfunction, impaired folliculogenesis, ovarian and uterine atrophy, decrease in reproductive organs weight and reproductive performance in women. We reviewed role of the immunological profile such as pro-infiammatory cytokines and hormonal changes as main potential mechanisms related to this infection and development of maternal-fetal and reproductive disorders.

CONCLUSION

T. gondii is associated with several brain related disorders in both mothers and newborns, and also it is cause of several abnormalities in reproductive organs. Early diagnosis and treatment of the infection could be effective to significantly improve the clinical outcome.

Association between thyroid autoimmunity and Helicobacter pylori infection

BACKGROUND/AIMS

There have been controversial reports linking Helicobacter pylori infection to autoimmune thyroid disease (AITD). However, data regarding the relationship are limited for Asian populations, which have an extremely high prevalence of H. pylori infection. We performed this study to investigate the association between H. pylori infection and AITD in Koreans.

METHODS

This study involved adults aged 30 to 70 years who had visited a health promotion center. A total of 5,502 subjects were analysed. Thyroid status was assessed by free thyroxine, thyroid stimulating hormone, and anti-thyroid peroxidase antibody (TPO-Ab). Immunoglobulin G (IgG) antibodies to H. pylori were measured as an indication of H. pylori infection. We compared the prevalence of TPO-Ab in subjects with and without H. pylori infection.

RESULTS

H. pylori IgG antibodies were found in 2,875 subjects (52.3%), and TPO-Ab were found in 430 (7.8%). Individuals positive for H. pylori Ab were older than those negative for H. pylori Ab (p < 0.01). The proportion of females was significantly higher in the TPO-Ab positive group (41.0% vs. 64.2%, p < 0.01). Prevalence of TPO-Ab positivity was higher in subjects with H. pylori infection (8.6% vs. 7.00%, p = 0.03), and this association was significant after adjusting for age, sex, and body mass index (odds ratio, 1.02; 95% confidence interval, 1.00 to 1.03; p = 0.04).

CONCLUSIONS

In our study, prevalence of TPO-Ab positivity is more frequent in subjects with H. pylori infection. Our findings suggest H. pylori infection may play a role in the development of autoimmune thyroiditis.

Molecular mimicry and autoimmune thyroid disease

Hypothesized 40 years ago, molecular mimicry has been thereafter demonstrated as an extremely common mechanism by which microbes elude immune response and modulate biosynthetic/metabolic pathways of the host. In genetically predisposed persons and under particular conditions, molecular mimicry between microbial and human antigens can turn a defensive immune response into autoimmunity. Such triggering role and its pathogenetic importance have been investigated and demonstrated for many autoimmune diseases. However, this is not the case for autoimmune thyroid disease, which appears relatively neglected by this field of research. Here we review the available literature on the possible role of molecular mimicry as a trigger of autoimmune thyroid disease. Additionally, we present the results of in silico search for amino acid sequence homologies between some microbial proteins and thyroid autoantigens, and the potential pathogenetic relevance of such homologies. Relevance stems from the overlap with known autoepitopes and the occurrence of specific HLA-DR binding motifs. Bioinformatics data published by our group support and explain the triggering role of Borrelia, Yersinia, Clostridium botulinum, Rickettsia prowazekii and Helicobacter pylori. Our new data suggest the potential pathogenic importance of Toxoplasma gondii, some Bifidobacteria and Lactobacilli, Candida albicans, Treponema pallidum and hepatitis C virus in autoimmune thyroid disease, indicating specific molecular targets for future research. Additionally, the consistency between in silico prediction of cross-reactivity and experimental results shows the reliability and usefulness of bioinformatics tools to precisely identify candidate molecules for in vitro and/or in vivo experiments, or at least narrow down their number.

A possible link between the Epstein-Barr virus infection and autoimmune thyroid disorders

The Epstein-Barr virus (EBV), also known as human herpesvirus 4, is a member of the Herpesviridae virus family. EBV infection can cause infectious mononucleosis (IM) in the lytic phase of EBV's life cycle. Past EBV infection is associated with lymphomas, and may also result in certain allergic and autoimmune diseases. Although potential mechanisms of autoimmune diseases have not been clearly elucidated, both genetic and environmental factors, such as infectious agents, are considered to be responsible for their development. In addition, EBV modifies the host immune response. The worldwide prevalence of autoimmune diseases shows how common this pathogen is. Normally, the virus stays in the body and remains dormant throughout life. However, this is not always the case, and a serious EBV-related illness may develop later in life. This explains the chronic course of autoimmune diseases that is often accompanied by exacerbations of symptoms. Based on the present studies, EBV infection can cause autoimmune diseases, such as systemic lupus erythematosus (SLE), multiple sclerosis (MS), rheumatoid arthritis (RA), Sjögren's syndrome, and autoimmune hepatitis. The EBV has also been reported in patients with autoimmune thyroid disorders. Although EBV is not the only agent responsible for the development of autoimmune thyroid diseases, it can be considered a contributory factor.

The correlation between Toxoplasma gondii infection and prenatal depression in pregnant women

Previous studies have demonstrated that latent toxoplasmosis is associated with neuropsychiatric disorders. We evaluated the correlation between Toxoplasma gondii infection and prenatal depression. In this case-control study, we enrolled 116 depressed pregnant women and 244 healthy controls. The Edinburgh Postpartum Depression Scale (EPDS) was used to evaluate the depression symptom severity in study participants. All participants were screened for the anti-Toxoplasma IgG by enzyme-linked immunosorbent assay. Seroprevalence of T. gondii did not significantly differ between the depressed pregnant women and healthy controls (OR = 1.4; 95 % CI = 0.9-2.19; P = 0.142). T. gondii IgG titer was significantly higher in depressed women (18.6 ± 10.9 IUs) than those in the control group (13.6 ± 8.1 IUs) (z = -5.36, P < 0.001). The T. gondii-positive depressed women showed a positive correlation of T. gondii IgG titer with the EPDS scores (r = 0.52; P < 0.01). The mean EPDS score was also significantly higher in the T. gondii-positive depressed women (20.7 ± 2.7) compared with the controls (18.36 ± 2.7) (P < 0.001). The results obtained from the current study revealed that T. gondii infection might affect susceptibility to depression and severity of depressive symptoms in pregnant women, particularly in those patients who have high antibody titers. Further study is required to fully elucidate the characteristics and mechanisms of this association.

A biopsychosocial approach to primary hypothyroidism: treatment and harms data from a randomized controlled trial

BACKGROUND

Hypothyroidism is a common endocrine condition. There is evidence to suggest that, for a proportion of sufferers, the standard medical treatment does not completely reverse the constitutional and neuropsychiatric symptoms brought about by this condition. The management of hypothyroidism follows a biomedical model with little consideration given to alternative management approaches. There exists anecdotal evidence and case reports supporting the use of a biopsychosocial-based intervention called Neuro-Emotional Technique (NET) for this population. The aim of this study was to explore the potential short-medium term clinical efficacy and safety of NET for individuals with primary hypothyroidism.DesignPlacebo-controlled, blinded, parallel groups, randomized trial.

METHODS

Ninety adults with a diagnosis of primary hypothyroidism were recruited from Sydney, Australia. Blinded participants were randomized to either the NET or placebo group and received ten intervention sessions over a six week period. The primary outcome involved the measurement of states of depression using the DASS-42 questionnaire. Secondary outcomes included thyroid function, thyroid autoimmunity testing, SF-36v2 questionnaire, resting heart rate and temperature measurement. Outcomes were obtained at baseline, seven weeks and six months. Questionnaires were completed at the private clinics, and serum measures were obtained and analysed at commercial pathology company locations. Heart rate and temperature were also measured daily by participants. Linear mixed-effects models were used to analyse the continuous outcomes. Unadjusted odds ratios with 95% confidence intervals were calculated for the binary outcomes.

RESULTS

Participants were randomly allocated to the NET (n=44) and placebo (n=46) groups. A proportion of the sample displayed neuropsychiatric disturbances and alterations in quality of life measures at baseline. There were no statistically significant or clinically relevant changes in the primary or secondary outcomes between the NET and placebo groups at time seven weeks or six months. There were a few short-lived minor adverse events reported in both the NET and placebo groups that coincided with the application of the intervention.

CONCLUSIONS

The application of the NET intervention appears to be safe, but did not confer any clinical benefit to the participants in this study and is unlikely to be of therapeutic use in a hypothyroid population.

CLINICAL TRIALS REGISTRATION NUMBER

Australian and New Zealand Clinical Trials Registry Number: 12607000040460.

Effects of latent toxoplasmosis on autoimmune thyroid diseases in pregnancy

BACKGROUND

Toxoplasmosis, one of the most common zoonotic diseases worldwide, can induce various hormonal and behavioural alterations in infected hosts, and its most common form, latent toxoplasmosis, influences the course of pregnancy. Autoimmune thyroid diseases (AITD) belong to the well-defined risk factors for adverse pregnancy outcomes. The aim of this study was to investigate whether there is a link between latent toxoplasmosis and maternal AITD in pregnancy.

METHODS

Cross-sectional study in 1248 consecutive pregnant women in the 9-12th gestational weeks. Serum thyroid-stimulating hormone (TSH), thyroperoxidase antibodies (TPOAb), and free thyroxine (FT4) were assessed by chemiluminescence; the Toxoplasma status was detected by the complement fixation test (CFT) and anti-Toxoplasma IgG enzyme-linked immunosorbent assay (ELISA).

RESULTS

Overall, 22.5% of the women were positive for latent toxoplasmosis and 14.7% were screened positive for AITD. Women with latent toxoplasmosis had more often highly elevated TPOAb than the Toxoplasma-negative ones (p = 0.004), and latent toxoplasmosis was associated with decrease in serum TSH levels (p = 0.049). Moreover, we found a positive correlation between FT4 and the index of positivity for anti-Toxoplasma IgG antibodies (p = 0.033), which was even stronger in the TPOAb-positive Toxoplasma-positive women, (p = 0.014), as well as a positive correlation between FT4 and log2 CFT (p = 0.009).

CONCLUSIONS

Latent toxoplasmosis was associated with a mild increase in thyroid hormone production in pregnancy. The observed Toxoplasma-associated changes in the parameters of AITD are mild and do not seem to be clinically relevant; however, they could provide new clues to the complex pathogenesis of autoimmune thyroid diseases.

Toxoplasmosis--a global threat. Correlation of latent toxoplasmosis with specific disease burden in a set of 88 countries

BACKGROUND

Toxoplasmosis is becoming a global health hazard as it infects 30-50% of the world human population. Clinically, the life-long presence of the parasite in tissues of a majority of infected individuals is usually considered asymptomatic. However, a number of studies show that this 'asymptomatic infection' may also lead to development of other human pathologies.

AIMS OF THE STUDY

The purpose of the study was to collect available geoepidemiological data on seroprevalence of toxoplasmosis and search for its relationship with mortality and disability rates in different countries.

METHODS AND FINDINGS

Prevalence data published between 1995-2008 for women in child-bearing age were collected for 88 countries (29 European). The association between prevalence of toxoplasmosis and specific disease burden estimated with age-standardized Disability Adjusted Life Year (DALY) or with mortality, was calculated using General Linear Method with Gross Domestic Product per capita (GDP), geolatitude and humidity as covariates, and also using nonparametric partial Kendall correlation test with GDP as a covariate. The prevalence of toxoplasmosis correlated with specific disease burden in particular countries explaining 23% of variability in disease burden in Europe. The analyses revealed that for example, DALY of 23 of 128 analyzed diseases and disease categories on the WHO list showed correlations (18 positive, 5 negative) with prevalence of toxoplasmosis and another 12 diseases showed positive trends (p<0.1). For several obtained significant correlations between the seroprevalence of toxoplasmosis and specific diseases/clinical entities, possible pathophysiological, biochemical and molecular explanations are presented.

CONCLUSIONS

The seroprevalence of toxoplasmosis correlated with various disease burden. Statistical associations does not necessarily mean causality. The precautionary principle suggests however that possible role of toxoplasmosis as a triggering factor responsible for development of several clinical entities deserves much more attention and financial support both in everyday medical practice and future clinical research.

Toxoplasma gondii: bystander or cofactor in rheumatoid arthritis

Parasitic infections may induce variable immunomodulatory effects and control of autoimmune disease. Toxoplasma gondii (T. gondii) is a ubiquitous intracellular protozoan that was recently associated with autoimmunity. This study was undertaken to investigate the seroprevalence and clinical correlation of anti-T. gondii antibodies in patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). We evaluated sera from European patients with RA (n = 125) and SLE (n = 164) for the prevalence of anti-T. gondii IgG antibodies (ATXAb), as well as other common infections such as Cytomegalovirus, Epstein-Barr, and Rubella virus. The rates of seropositivity were determined utilizing the LIAISON chemiluminescent immunoassays (DiaSorin, Italy). Our results showed a higher seroprevalence of ATXAb in RA patients, as compared with SLE patients [63 vs. 36 %, respectively (p = 0.01)]. The rates of seropositivity of IgG against other infectious agents were comparable between RA and SLE patients. ATXAb-seropositivity was associated with older age of RA patients, although it did not correlate with RA disease activity and other manifestations of the disease. In conclusion, our data suggest a possible link between exposure to T. gondii infection and RA.

Prevalence of anti-Toxoplasma antibodies in patients with autoimmune diseases

The identification of etiological factors in the induction of autoimmunity has remained elusive despite an enormous effort at dissection of the molecular structure of the target antigens and effector mechanisms. One characteristic feature of autoantigens is their repetitive structure as well as their conservation and evolution. Toxoplasma (T.) gondii is a primitive protozoan. We hypothesized that patients with autoimmune disease would have broad reactions against Toxoplasma antigens based on autoantigen conservation. To address this issue, we assessed serologic evidence of reactivity to Toxoplasma gondii along with a large profile of autoantibodies in patients with various autoimmune diseases (AID). We included sera of 1514 patients with 11 different AID collected from referral centers in Europe and Latin America as well as from 437 geographically matched controls, for the prevalence of anti Toxoplasma antibodies (ATxA) IgG and IgM and serum autoantibodies utilizing the BioPlex 2200 system (Bio- Rad Laboratories, USA). Serum ATxA IgG were positive in 42% of patients with AID versus 29% of controls (p < 0.0001). Among Europeans, ATxA IgG were associated with anti-phospholipid syndrome (APS; p < 0.0001), cryoglobulinemia (p < 0.0001), ANCA-associated vasculitides (p < 0.01), autoimmune thyroid diseases (p < 0.0001), systemic sclerosis (SSc; p < 0.0001) and rheumatoid arthritis (RA; p < 0.0001). Of note, Latin American RA sera exhibited similar frequency of ATxA IgG as controls. ATxA IgM were more prevalent in European patients with APS (p < 0.01), SSc (p < 0.05) and inflammatory bowel disease (IBD, p < 0.05) than in controls. Further, in AID patients the presence of ATxA correlated with autoantibodies characteristic of APS (anti- cardiolipin, B2GPI, complex of cardiolipin- B2GPI, prothrombin, phosphatydilethanolamine), and of SSc (anti-centromere, Scl-70). Our findings suggest that T. gondii may contribute to the pathogenesis of AID. This interaction may depend on or explain observed geoepidemiological variance in AID.

Hashimoto's Thyroiditis: From Genes to the Disease

Hashimoto's thyroiditis (HT) is the most prevalent autoimmune thyroid disorder. Intrathyroidal lymphocytic infiltration is followed by a gradual destruction of the thyroid gland which may lead to subclinical or overt hypothyroidism. Biochemical markers of the disease are thyroid peroxidase and/or thyroglobulin autoantibodies in the serum which are present with a higher prevalence in females than in males and increase with age. Although exact mechanisms of aetiology and pathogenesis of the disorder are not completely understood, a strong genetic susceptibility to the disease has been confirmed predominantly by family and twin studies. Several genes were shown to be associated with the disease occurrence, progression, and severity. Genes for human leukocyte antigen, cytotoxic T lymphocyte antigen-4, protein tyrosine phosphatase nonreceptor-type 22, thyroglobulin, vitamin D receptor, and cytokines are considered to be of utmost importance. Amongst endogenous factors for the disease development, the attention is focused predominantly on female sex, pregnancy with postpartum period and fetal microchimerism. Environmental factors influencing HT development are iodine intake, drugs, infections and different chemicals. Disturbed self-tolerance accompanied by the increased antigen presentation is a prerequisite for the HT occurrence, whereas proper interaction of thyroid cells, antigen presenting cells, and T cells are necessary for the initiation of thyroid autoimmunity. Secreted cytokines lead predominantly to T-helper type 1 (Th1) response as well as to Th 17 response which has only recently been implicated. Final outcome of HT is thyroid destruction which is mostly a consequence of the apoptotic processes combined with T-cell mediated cytotoxicity.

Prenatal depression and anxiety in Toxoplasma gondii-positive women

OBJECTIVE

This study analyzed a relationship between prenatal mood states and serologic evidence of immune response to Toxoplasma gondii. A secondary aim was to determine whether thyroid peroxidase autoantibody status was related to T gondii status.

STUDY DESIGN

Pregnant women (n = 414) were measured at 16-25 weeks' gestation with demographic and mood questionnaires and a blood draw. All plasma samples were analyzed for thyroid peroxidase and T gondii immunoglobulin G, tryptophan, kynurenine, and neopterin. T gondii serotypes were also measured in the women who were T gondii positive. Cytokines were available on a subset (n = 142).

RESULTS

Women with serologic evidence of exposure to T gondii (n = 44) showed positive correlations between immunoglobulin G levels and the Profile of Mood States depression and anxiety subscales. Plasma tumor necrosis factor-α was higher in women who were positive for T gondii. Serotypes were type I (27%), type II (31%), and unclassified (42%, which shows intermediate levels of reactivity). The depression and anxiety scores were highest in type I, but this was not significant. The Profile of Mood States vigor score was lowest in type II, compared with the type I or unclassified groups.

CONCLUSION

Higher T gondii immunoglobulin G titers in infected women were related to anxiety and depression during pregnancy. Subclinical reactivation of T gondii or immune responses to T gondii may worsen mood in pregnant women.

Environmental factors and thyroid autoimmunity

Thyroid autoimmune disease, a multifactorial organ-specific autoimmune disorder, is marking a constant increase worldwide. It is thought to be caused by multiple environmental factors triggering autoimmune response in genetically susceptible individuals, though the exact mechanisms linking environmental factors to thyroid autoimmunity are not as yet well understood. Nevertheless, there is increasing evidence that mainly nutritive factors and environmental pollution by metals and chemicals (e.g. organochlorines, pesticides) are the main factors in the present-day spread of this disease. This review presents an overview of the current knowledge regarding environmental factors, their association with genetics and their impact on the immune system.

Graves' disease associated with infectious mononucleosis due to primary Epstein-Barr virus infection: report of 3 cases

Although the etiology of Graves' disease is still not clear, it is generally suggested that environmental factors such as infections contribute to the development of Graves' disease. We report here three cases of Graves' disease which presented simultaneously with infectious mononucleosis due to primary EBV infection. Acute EBV infection might play an important role in the onset of Graves' disease. These three women complained of a sore throat or neck pain, resembling subacute thyroiditis. In the case of thyrotoxicosis accompanied by sore throat or neck pain, Graves' disease must be distinguished from subacute thyroiditis.

Drugs and autoimmunity--a contemporary review and mechanistic approach

Drug-induced autoimmunity is an idiosyncratic, non-IgE immune related drug reaction. Interestingly, although many drugs have been reported to induce autoantibodies, only a few have a definitive association with drug-induced autoimmune disease. The prototype disease is drug-induced lupus and the typical drug for drug-induced lupus is minocycline. The production of autoantibodies and the induction of symptoms in drug-induced lupus results from a variety of mechanisms, which can include suppression of central or peripheral tolerance, alteration of gene transcription in T and B cells, abnormal cytokine and/or cytokine receptor balance and function, chromatin structure modification and antigen modification. Multiple mechanisms may apply for different drugs, and understanding the pharmacological actions of these agents helps us decipher the etiology. For example, DNA hypomethylation may occur with hydralazine, which leads to increased transcription, increased LFA-1, the generation of autoreactive T cells and a breakdown in peripheral tolerance. Frequently, more than one pathway may be involved. Interestingly, most patients with newly formed autoantibodies resulting from drugs do not develop clinical disease. Nonetheless, the explosion in the use of biological modifiers has been associated with production of autoantibodies, an observation that illustrates the complex nature of these interactions, in that these agents are frequently used to treat autoimmunity, yet may produce autoimmune diseases themselves.