Toxoplasmosis seroprevalence in rheumatoid arthritis patients: A systematic review and meta-analysis

Parasitic helminths and protozoa: Treasure boxes of disease modifying anti-rheumatic drugs

Parasites generally survive in their hosts by employing various immunomodulation and immune evasion mechanisms. "helminth therapy" is one strategy that harnesses these parasite-specific beneficial properties for the therapeutic treatment of autoimmune and allergic diseases. Although numerous experimental reports have documented the anti-autoimmune activities of parasitic infections and parasite-derived products, the underlying mechanisms remain insufficiently elucidated due to the significant diversity among parasite species and autoimmune conditions. Rheumatoid arthritis (RA) is one of the most prevalent autoimmune disorders, presenting a substantial opportunity for the therapeutic use of parasites as novel disease-modifying antirheumatic drugs (DMARDs). In this paper, we summarize the immunomodulatory properties of parasites, focusing on their anti-arthritic mechanisms, and discuss the potential of parasite-derived products for the treatment of RA.

Schizophrenia and Rheumatoid Arthritis Genetic Scenery: Potential Non-HLA Genes Involved in Both Diseases Relationship

Background: The link between rheumatoid arthritis (RA) and schizophrenia (SZ) has long been a hot topic of deliberation among scientists from various fields. Especially when it comes to genetics, the connection between RA and SZ is still up for discussion, as can be observed in this study. The HLA genes are the most disputed in identifying a connection between the two diseases, but a more thorough investigation of other genes that may be ignored could yield something even more interesting. Thus, finding the genes responsible for this long-sought relationship will necessitate looking for them. Materials and Methods: Shared and overlapped associated genes involved between SZ and RA were extracted from four databases. The overlapping genes were examined using Database for Annotation, Visualization and Integrated Discovery (DAVID) and InnateDB to search the pertinent genes that concatenate between these two disorders. Results: A total of 91 overlapped genes were discovered, and that 13 genes, divided into two clusters, showed a similarity in function, suggesting that they may serve as an important meeting point. FCGR2A, IL18R, BTNL2, AGER, and CTLA4 are five non-HLA genes related to the immune system, which could lead to new discoveries about the connection between these two disorders. Conclusion: An in-depth investigation of these functionally comparable non-HLA genes that overlap could reveal new interesting information in both diseases. Understanding the molecular and immune-related aspects of RA and SZ may shed light on their etiology and inform future research on targeted treatment strategies.

Vaccination with Toxoplasma lysate antigen or its encapsulated niosomes form immunomodulates adjuvant-induced arthritis through JAK3 downregulation

BACKGROUND

Inflammatory autoimmune arthritis like that present in rheumatoid arthritis (RA) is treated by medications with many side effects. This study was a trial to benefit from Toxoplasma immune-modulatory effects on its host to treat arthritis in rat model resembling joints affection of RA. To avoid hazards of infection, Toxoplasma lysate antigen (TLA) was given instead of the whole infection, in addition to giving its encapsulated niosomes form, assuming that it would enhance the effect of TLA alone, to compare effects of both on disease activity with that of prednisolone.

METHODS

Swiss albino rats were divided into 6 groups: normal control group and the remaining 5 groups were injected by CFA adjuvant to induce arthritis; one of those groups was the untreated model. Each of the other groups received one of the following (TLA, TLA-encapsulated niosomes, prednisolone or niosomes) for comparison of their results. Inflammatory markers measured at the end of the experiment were: interleukin 17 (IL-17), IL-10 and CRP by ELISA technique; histopathological assessment of the biopsied hind paw joints was done and also, Janus kinase 3 (JAK3) expression was assessed by immunohistochemistry.

RESULTS

TLA and TLA-encapsulated niosomes both mitigated the signs of clinical and histopathological arthritis and were having anti-inflammatory effects (decreased CRP, IL-17 and JAK3 expressions, while increased IL-10 levels) with better effects in TLA-encapsulated niosomes-treated RA group, both groups' results were comparable to prednisolone. Niosomes also gave some anti-inflammatory effects but were mild in comparison to TLA and TLA-encapsulated niosomes.

CONCLUSION

Vaccination with both TLA and TLA-encapsulated niosomes for the first time in adjuvant-induced arthritis ameliorated the disease through diversion of immune system and JAK3 downregulation. Both vaccinations should be further tested to evaluate the possibility of their introduction for disease treatment and in other autoimmune diseases.

Plasma Cholinesterase Activity in Patients With Rheumatoid Arthritis and Toxoplasmosis

Background and objective Rheumatoid arthritis (RA) is a chronic autoimmune disease causing synovium inflammation and functional impairment. Toxoplasmosis is an intracellular zoonotic parasitic infection and a risk factor in immunosuppressed diseases including RA. The involvement of the cholinergic mechanism is not clear when both diseases exist in combination. This study aimed to examine plasma cholinesterase (ChE) activity in patients suffering from RA with concomitant toxoplasmosis, taking into account the enzyme susceptibility to in vitro inhibitory challenge with the organophosphate dichlorvos in RA patients. Methods This was a case-control study involving 88 RA patients and 61 healthy controls of both genders. The RA patients were allocated into three groups. The first group received no therapy (n=14), the second group received conventional anti-arthritis therapy (n=49), and the third group received conventional + biologic therapy (n=25). Plasma ChE activity was determined by an electrometric method. Plasma samples were screened for Toxoplasma gondii (T. gondii) infection, using ELISA T. gondii antibodies IgG and IgM. In vitro inhibition of plasma ChE activity was assessed by incubating the samples with dichlorvos at 0.25 and 0.5 μM. The time-dependent dichlorvos (0.25 μM)-induced plasma ChE inhibition and its kinetics were determined. Results The RA patients comprised 76 (86.4%) females and 12 males (13.6%), whereas healthy controls included 22 (36.1%) females and 39 (63.9%) males. The rates of toxoplasmosis IgG positivity in controls and RA patients were 26.2% and 39.8%, respectively. Plasma ChE activity in patients with RA was significantly higher than that in the control group, by 16%. Plasma ChE values of RA patients with conventional therapy and conventional + biologic therapy were higher than that of the control group, by 18% and 27%, respectively. Odds and risk ratios of elevated plasma ChE activity (20%) in RA patients with therapy indicated that high plasma ChE activity among RA patients with therapy is a risk factor. The plasma ChE activity of T. gondii IgG-positive RA patients was not significantly different from that of the IgG-negative ones. Dichlorvos at 0.25 and 0.5 μM significantly inhibited in vitro plasma ChE activity in controls and RA patients. The rates of plasma ChE inhibition by dichlorvos were lower in the RA groups with conventional therapy in comparison with those in the control group (77% vs. 91%). Examining the dichlorvos time-dependent ChE inhibition kinetics, RA groups showed increases in the half-life of inhibition by 23.6% to 32.7% and the total inhibition time by 23.5% to 32.5%, together with decreases in the inhibition rate constant by 19% to 24.5%, an indication of reduced inhibition rate of plasma ChE activity compared to that of the control group. Conclusions The autoimmune nature of RA and its chronicity might have contributed to the increase in plasma ChE activity among the patients. This increase in enzyme activity could be a risk factor in RA patients undergoing conventional therapy alone or in combination with biologic therapy; however, the clinical significance of such a condition remains obscure at present. The in vitro inhibition of plasma ChE activity in RA patients suggests reduced susceptibility of the enzyme to ChE inhibition by dichlorvos. Toxoplasmosis was not a risk factor when plasma ChE activity was taken into account among RA patients.

Is Toxoplasma gondii infection a concern in individuals with rheumatic diseases? Evidence from a case-control study based on serological diagnosis

Toxoplasma gondii infection in clinical cases of rheumatic diseases is increasing, whereas, the relationship between T. gondii infection and rheumatic diseases is still ambiguous and contradictory. Thus, the present case-control study based on serological diagnosis was carried out to identify the underlying relationship between T. gondii infection and rheumatic diseases in China. Serological results showed that rheumatic patients (17.25%, 79/458) had a significantly higher T. gondii seroprevalence than control subjects (10.70%, 49/458) (p = 0.004). However, the difference in T. gondii seroprevalence among clinical rheumatic disease forms was insignificant. Moreover, disease duration not effect the T. gondii seroprevalence in the included clinical rheumatic patients. Three risk factors (presence of cats at home, blood transfusion history, and consumption of raw shellfish) were identified through multivariate analysis to affect the T. gondii seroprevalence in the included clinical rheumatic patients. In conclusion, these results indicate that the latent T. gondii infection in clinical rheumatic patients should cause alarm and attention in the course of future scientific research or clinical treatment.

In Silico Vaccine Design and Expression of the Multi-Component Protein Candidate against the Toxoplasma gondii Parasite from MIC13, GRA1, and SAG1 Antigens

Background

We aimed to design a B and T cell recombinant protein vaccine of Toxoplasma gondii with in silico approach. MIC13 plays an important role in spreading the parasite in the host body. GRA1 causes the persistence of the parasite in the parasitophorous vacuole. SAG1 plays a role in host-cell adhesion and cell invasion.

Methods

Amino acid positions 73-272 from MIC13, 71-190 from GRA1, and 101-300 from SAG1 were selected and joined with linker A(EAAAK)A. The structures, antigenicity, allergenicity, physicochemical properties, as well as codon optimization and mRNA structure of this recombinant protein called MGS1, were predicted using bioinformatics servers. The designed structure was synthesized and then cloned in pET28a (+) plasmid and transformed into Escherichia coli BL21.

Results

The number of amino acids in this antigen was 555, and its antigenicity was estimated to be 0.6340. SDS-PAGE and Western blotting confirmed gene expression and successful production of the protein with a molecular weight of 59.56kDa. This protein will be used in our future studies as an anti-Toxoplasma vaccine candidate in animal models.

Conclusion

In silico methods are efficient for understanding information about proteins, selecting immunogenic epitopes, and finally producing recombinant proteins, as well as reducing the time and cost of vaccine design.

Identification of the immune-related biomarkers in Behcet's disease by plasma proteomic analysis

BACKGROUND

This study aimed to investigate the expression profile of immune response-related proteins of Behcet's disease (BD) patients and identify potential biomarkers for this disease.

METHODS

Plasma was collected from BD patients and healthy controls (HC). Immune response-related proteins were measured using the Olink Immune Response Panel. Differentially expressed proteins (DEPs) were used to construct prediction models via five machine learning algorithms: naive Bayes, support vector machine, extreme gradient boosting, random forest, and neural network. The prediction performance of the five models was assessed using the area under the curve (AUC) value, recall (sensitivity), specificity, precision, accuracy, F1 score, and residual distribution. Subtype analysis of BD was performed using the consensus clustering method.

RESULTS

Proteomics results showed 43 DEPs between BD patients and HC (P < 0.05). These DEPs were mainly involved in the Toll-like receptor 9 and NF-κB signaling pathways. Five models were constructed using DEPs [interleukin 10 (IL10), Fc receptor like 3 (FCRL3), Mannan-binding lectin serine peptidase 1 (MASP1), NF2, moesin-ezrin-radixin like (MERLIN) tumor suppressor (NF2), FAM3 metabolism regulating signaling molecule B (FAM3B), and O-6-methylguanine-DNA methyltransferase (MGMT)]. Among these models, the neural network model showed the best performance (AUC = 0.856, recall: 0.692, specificity: 0.857, precision: 0.900, accuracy: 0.750, F1 score: 0.783). BD patients were divided into two subtypes according to the consensus clustering method: one with high disease activity in association with higher expression of tripartite motif-containing 5 (TRIM5), SH2 domain-containing 1A (SH2D1A), phosphoinositide-3-kinase adaptor protein 1 (PIK3AP1), hematopoietic cell-specific Lyn substrate 1 (HCLS1), and DNA fragmentation factor subunit alpha (DFFA) and the other with low disease activity in association with higher expression of C-C motif chemokine ligand 11 (CCL11).

CONCLUSIONS

Our study not only revealed a distinctive immune response-related protein profile for BD but also showed that IL10, FCRL3, MASP1, NF2, FAM3B, and MGMT could serve as potential immune biomarkers for this disease. Additionally, a novel molecular disease classification model was constructed to identify subsets of BD.

Toxoplasma and Toxocara seropositivity in juvenile idiopathic arthritis and its relation to disease activity and type of therapies

Juvenile idiopathic arthritis (JIA) is the most frequently encountered autoimmune rheumatic disease in children. To our knowledge, this is the first study aimed to estimate the frequency of Toxoplasma gondii (T. gondii) and Toxocara seropositivity in JIA and assess its relation to the disease activity, IL-10 levels, and type of the received therapies. This study was conducted on 43 JIA patients and 50 cases as a control group. All participants were evaluated by disease activity score (JADAS-27), and the presence of specific IgG and IgM antibodies against T. gondii and IgG against Toxocara species using an enzyme-linked immunosorbent assay. IL-10 serum levels were measured using an ELISA kit. The results show that JIA patients have significantly higher seropositivity for anti-T. gondii IgG compared to control subjects (p = 0.02) and a non-significant difference for Toxocara seropositivity (p = 0.41). All participants were negative for IgM anti-Toxoplasma gondii. Demographic parameters did not significantly affect these seroprevalence frequencies (p > 0.05). IL-10 was significantly higher among JIA patients compared to controls (p = 0.007) and seropositive anti-T. gondii JIA exhibited significantly higher IL-10 levels compared to seronegative ones (p = 0.03). Seropositive anti-T. gondii IgG JIA patients had a significantly higher disease activity score (JADAS-27) than seronegative anti-T. gondii IgG cases (p = 0.02). There was a significant positive correlation between anti-T. gondii IgG and JADAS-27 score (p = 0.009). A significant association was detected between T. gondii infection and DMARDs including the biological therapies (p < 0.05). Overall, this study supports a possible association between T. gondii infection and JIA, IL-10, disease activity score, and DMARDs therapies. It is possible that IL-10 plays a role in the development of JIA and contributes to persistent asymptomatic infection with T. gondii in JIA patients. As a result, a recommendation for screening tests for T. gondii infection among JIA patients is crucial before and during commencing DMARDs therapies and closely monitoring early signs of infection.

Evaluation of Specific Cellular and Humoral Immune Response to Toxoplasma gondii in Patients with Autoimmune Rheumatic Diseases Immunomodulated Due to the Use of TNF Blockers

(1) Background: TNF antagonists have been used to treat autoimmune diseases (AD). However, during the chronic phase of toxoplasmosis, TNF-α and TNFR play a significant role in maintaining disease resistance and latency. Several studies have demonstrated the risk of latent infections’ reactivation in patients infected with toxoplasmosis. Our objective was to verify whether patients with autoimmune rheumatic diseases, who use TNF antagonists and/or synthetic drugs and had previous contact with Toxoplasma gondii (IgG+), present any indication of an increased risk of toxoplasmosis reactivation. (2) Methods: Blood samples were collected, and peripheral blood mononuclear cells (PBMCs) were evaluated after stimulation with antigens of Toxoplasma gondii, with anti-CD3/anti-CD28 or without stimulus, at 48 and 96 h. CD69+, CD28+, and PD-1 stains were evaluated, in addition to intracellular expression of IFN-γ, IL-17, and IL-10 by CD4+ and the presence of regulatory CD4+ T cells by labeling CD25+, FOXP3, and LAP. The cytokines IL-2, IL-4, IL-6, IL-10, IFN-γ, TNF-α, and IL-17 were measured in the culture supernatant after 96 h. Serology for IgG and IgG1 was evaluated. (3) Results: There were no differences in the levels of IgG and IgG1 between the groups, but the IgG1 avidity was reduced in the immunobiological group compared to the control group. All groups exhibited a significant correlation between IgG and IgG1 positivity. CD4+ T lymphocytes expressing PD-1 were increased in individuals suffering from autoimmune rheumatic diseases and using disease-modifying antirheumatic drugs. In addition, treatment with TNF blockers did not seem to influence the populations of regulatory T cells and did not interfere with the expression of the cytokines IFN-γ, IL-17, and IL-10 by CD4+ cells or the production of cytokines by PBMCs from patients with AD. (4) Conclusions: This study presents evidence that the use of TNF-α blockers did not promote an immunological imbalance to the extent of impairing the anti-Toxoplasma gondii immune response and predisposing to toxoplasmosis reactivation.

Overview of Apoptosis, Autophagy, and Inflammatory Processes in Toxoplasma gondii Infected Cells

Toxoplasma gondii (T. gondii) is an obligate intracellular parasite. During the parasitic invasion, T. gondii creates a parasitophorous vacuole, which enables the modulation of cell functions, allowing its replication and host infection. It has effective strategies to escape the immune response and reach privileged immune sites and remain inactive in a controlled environment in tissue cysts. This current review presents the factors that affect host cells and the parasite, as well as changes in the immune system during host cell infection. The secretory organelles of T. gondii (dense granules, micronemes, and rhoptries) are responsible for these processes. They are involved with proteins secreted by micronemes and rhoptries (MIC, AMA, and RONs) that mediate the recognition and entry into host cells. Effector proteins (ROP and GRA) that modify the STAT signal or GTPases in immune cells determine their toxicity. Interference byhost autonomous cells during parasitic infection, gene expression, and production of microbicidal molecules such as reactive oxygen species (ROS) and nitric oxide (NO), result in the regulation of cell death. The high level of complexity in host cell mechanisms prevents cell death in its various pathways. Many of these abilities play an important role in escaping host immune responses, particularly by manipulating the expression of genes involved in apoptosis, necrosis, autophagy, and inflammation. Here we present recent works that define the mechanisms by which T. gondii interacts with these processes in infected host cells.

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.

Cerebral Toxoplasmosis as an Uncommon Complication of Biologic Therapy for Rheumatoid Arthritis: Case Report and Review of the Literature

Toxoplasmosis is one of the most common opportunistic infections, mainly reported in patients with acquired immunodeficiency syndrome (AIDS). Patients with rheumatoid arthritis (RA) have also been linked to reactivation of toxoplasmosis due to immunosuppressive treatment, although biologic drugs have seldom been implicated. We present a case of cerebral toxoplasmosis in a 62-year-old female patient with RA after initiation of biologic therapy (adalimumab). The patient had detectable serum IgG antibodies to toxoplasma gondii, was also on chronic treatment with other non-biologic drugs and presented with worsening disorientation, unsteady gait and left hemiparesis. Imaging studies showed a space-occupying lesion in the right basal ganglia with ring-enhancement. Brain biopsy confirmed the diagnosis of toxoplasmosis and the patient was treated with pyrimethamine and sulfadiazine for 6 weeks, showing complete recovery on follow-up. A review of the literature yielded other four case reports of cerebral toxoplasmosis implying biologic drugs; however, data concerning toxoplasmosis serologic testing, prophylaxis and treatment in these patients are lacking. Each case must be carefully evaluated prior to treatment and a high-index of suspicion in seropositive patients is warranted. Since the use of biologic drugs is increasing, further research is needed to establish practical guidelines for seropositive patients receiving immunosuppressive treatment.

Toxoplasmosis Frequency Rate in Rheumatoid Arthritis Patients in Northeastern Iran

BACKGROUND

Toxoplasmosis is a zoonotic disease caused by the parasite Toxo-plasma gondii, a cosmopolitan intracellular parasite. It can be a risk factor for auto-immune diseases, including rheumatoid arthritis (RA). This study was designed to investigate the possible association between serological history of T. gondii infection and defined clinical manifestation of RA in Northeast of Iran.

METHODS

Overall, serum samples were collected from 50 RA patients and 40 healthy controls, from Qaem Hospital in Mashhad City, northeastern Iran in 2018. Seroprevalence of T. gondii infection was determined by ELISA.

RESULTS

The prevalence of anti -T. gondii IgG in RA patients 48% (24.50) was significantly higher than the control group 10% (4.40) (P <0.001). Erythrocyte sedimentation rate (ESR), anti-cyclic citrullinated peptide (anti-CCP) and (rheumatoid factor) RF levels between the RA and control groups (P <0.01). Control group were matched with patients for age, gender and living area.

CONCLUSION

Given that a high correlation has been demonstrated between positivity rate of anti-T. gondii IgG and RA in Northeastern Iran, further studies will be necessary to clarify the pathogenesis of T. gondii among these patients.

Global seroprevalence of Toxoplasma gondii in Camelidae: A systematic review and meta-analysis

PURPOSE

The present study aimed to analyze data available of the seroprevalence of Toxoplasma gondii (T. gondii) among camelids around the world.

METHODS

The search was performed using seven international databases including Scopus, PubMed, Google Scholar, ProQuest, ScienceDirect, Web of Science, and EMBASE up to 11 October 2018. Random effects model was used to determine the pooled seroprevalence of T. gondii infection with 95% confidence intervals (CI) and analyzed data from four continents. Subgroup and meta-regression analyses were also performed according to continent and gender.

RESULTS

In total, 42 studies out of 3517 published articles involving 14,542 camels from 17 countries were included for the final analyses. The global pooled seroprevalence of T. gondii infection in the Camelidae family was 28.16% (95% CI 23.64-32.68%). Besides, the highest seroprevalence rate was in Europe (49.64%) followed by Africa (37.63%), America (21.76%), and Asia (17.58%). Moreover, the overall seroprevalence rates of T. gondii infection were 22% (95% CI 10-33%) and 15% (95% CI 9-22%) for the females and males, respectively.

CONCLUSION

This meta-analysis showed a high seroprevalence of T. gondii infection in camelids as these animals play an important role in the transmission cycle of this zoonotic disease.

Parasite-based interventions in systemic lupus erythematosus (SLE): A systematic review

BACKGROUND

The hygiene hypothesis proposed in 1989 expresses that allergic and infectious diseases are inversely related. Accordingly, it has been demonstrated that infection with some microorganisms such as parasites and helminths can provide a potential immunity and prevent the onset of some life-threatening autoimmune diseases like systemic lupus erythematosus (SLE). Therefore, in this comprehensive study, we systematically reviewed and discussed the use of live parasites or parasitic products in the treatment of mouse models of SLE.

METHODS

The present systematic review was performed using the following search terms: ("systemic lupus erythematosus" OR "SLE" OR "lupus") AND ("parasite" OR "protozoa" OR "helminths" OR "worms" OR "helminth" OR "worm") in PubMed, Scopus, and Web of Science online databases. We included studies reporting the effect of any intervention using parasites or parasitic-based products on animal models of SLE, which were published until January 20th, 2021 without any language or date restrictions. For each included study, we extracted the authors' names, publication year, type of animal, number of groups, types of intervention, sample size, changes in immunologic cells, auto-Abs, cytokines, and blood cells count, urine analysis, histological analysis of kidney/spleen/liver, outcome and survival. (PROSPERO CRD42020160460).

RESULTS

A total of 17 eligible articles were included in this systematic review. Sixteen out of the 17 studies reported immunomodulating changes in immunologic cells, cytokines, and/or auto-Abs in mouse models of SLE after using parasitic interventions compared to not-infected or control groups. Moreover, 14 studies reported decreased level of proteinuria and/or favorable kidney, liver, or spleen histological changes.

CONCLUSION

In conclusion, we have demonstrated that parasites like Hymenolepis microstoma, TPC and ES-62 from Acanthocheilonema viteae, Plasmodium chabaudi, Schistosoma mansoni, and Toxoplasma gondii have favorable immunomodulating effects on SLE outcomes in lupus-prone mice.

The global status and genetic characterization of hydatidosis in camels (Camelus dromedarius): a systematic literature review with meta-analysis based on published papers

Hydatidosis is a potential zoonotic helminthic disease affecting a broad spectrum of mammals, including humans, worldwide. The current review was conducted to investigate the genotypic status and prevalence of hydatid disease in camels across the world. For the purpose of the study, the articles addressing the worldwide prevalence of hydatidosis in camels were searched in several English language databases. The search process resulted in the inclusion of 122 papers. Based on the data presented in the reviewed articles, the pooled prevalence of hydatid disease in camels across the world was measured at 23.75% (95% CI 20.15-27.55). Moreover, the subgroup analysis demonstrated significant differences in the overall prevalence of hydatidosis among camels based on year, geographic area, climate parameters, camel population, gender, infected organ, fertility rate of the cyst and laboratory diagnostic technique. Furthermore, the Echinococcus granulosus genotypes identified in camels with hydatidosis included G1, G2, G3, G1-G3, G5, G6, G7, G6-G7 and G6-G10, with G6 being the most common genotype throughout the world. The data obtained from the current study are central to the better conceptualization of the biological and epidemiological characteristics of E. granulosus s.l. genotypes around the world, which can be helpful in the planning and adoption of more comprehensive control strategies.

Latent Toxoplasma gondii infections are associated with elevated biomarkers of inflammation and vascular injury

BACKGROUND

Toxoplasma gondii is a protozoan parasite that infects cats as definitive hosts and other warm-blooded animals including humans as intermediate hosts. It forms infectious cysts in the brain, muscle and other tissues establishing life-long latent infection. Approximately 10% of the US population is infected. While latent infections are largely asymptomatic, they are associated with neurological deficits and elevated risks of neuropsychiatric diseases.

METHODS

This cross-sectional epidemiological study investigated associations of T. gondii infections with biomarkers of inflammation and vascular injury: soluble intercellular adhesion molecule 1 (ICAM-1), soluble vascular cell adhesion molecule 1 (VCAM-1), C-reactive protein (CRP), and serum amyloid A (SAA). Serum samples from 694 adults in the Raleigh-Durham-Chapel Hill, North Carolina metropolitan area were tested for IgG antibody response to T. gondii, and for the above biomarkers using commercially available assays.

RESULTS

T. gondii seroprevalence rate in this sample was 9.7%. Seropositivity was significantly associated with 11% (95% confidence limits 4, 20%) greater median levels of VCAM-1 (p = 0.003), and marginally significantly with 9% (1, 17%), and 36% (1, 83%) greater median levels of ICAM-1, and CRP, respectively (p = 0.04 for each) after adjusting for sociodemographic and behavioral covariates, while the 23% (- 7, 64%) adjusted effect on SAA was not statistically significant (p = 0.15).

CONCLUSIONS

Latent infections with T. gondii are associated with elevated biomarkers of chronic inflammation and vascular injury that are also known to be affected by ambient air pollution.

Toxoplasmosis of the central nervous system: Manifestations vary with immune responses

Toxoplasmosis is an opportunistic infection caused by Toxoplasma gondii (TG), which affects one third of the global human population and commonly involves the central nervous system (CNS)/brain despite the so-called CNS immune privilege. Symptomatic clinical disease of TG infection is much more commonly associated with immunodeficiency; clinicopathological manifestations of CNS toxoplasmosis are linked to individual immune responses including the CNS infiltration of T-cells that are thought to prevent the disease. In patients with autoimmune diseases, immune status is complicated mainly byimmunosuppressant and/or immunomodulatory treatment but typically accompanied by infiltration of T-cells that supposedly fight against toxoplasmosis. In this article, we review characteristics of CNS toxoplasmosis comparatively in immunocompromised patients, immunocompetent patients, and patients with coexisting autoimmune diseases, as well as CNS immune responses to toxoplasmosis with a representative case to demonstrate brain lesions at different stages. In addition to general understanding of CNS toxoplasmosis, our review reveals that clinical manifestations of CNS toxoplasmosis are commonly nonspecific, and incidental pathological findings of TG infection are relatively common in immunocompetent patients and patients with autoimmune diseases (compared to immunocompromised patients); CNS immune responses such as T-cell infiltrates vary in acute and chronic lesions of brain toxoplasmosis.

Sarcocystosis in Ruminants of Iran, as Neglected Food-Borne Disease: A Systematic Review and Meta-analysis

PURPOSE

Sarcocystis is a zoonotic parasitic pathogen which endangers the safety of meat and meat products. This systematic review and meta-analysis aimed to evaluate the prevalence rate and status of Sarcocystis spp. in ruminants as important food sources in Iran.

METHODS

Data were collected from papers indexed in five English language electronic databases (PubMed, Scopus, Web of Science, Science Direct, and Google Scholar) and four Persian electronic databases (IranMedex, SID, IranDoc, and Magiran) from January to April 2019. Papers were selected based on inclusion criteria. Data analysis was performed in StatsDirect statistical software, version 2.7.2.

RESULTS

The searching process resulted in the identification of 73 studies. Data analyses revealed that the total prevalence (95% confidence intervals) of Sarcocystis spp. in Iranian ruminants was 74.40% (64.01-83.56). In addition, a significant association was also observed between sarcocystosis infection in Iranian ruminants and year, host, location, and diagnostic technique (P < 0.001).

CONCLUSIONS

According to our data, the prevalence of Sarcocystis infection in ruminants is relatively high. High pathogenicity of some Sarcocystis spp. and the negative impact that the spread of some parasites among ruminants can have on human and animal health necessitate the direction of more attention toward monitoring, controlling, and preventing sarcocystosis.

Seroprevalence of toxoplasma gondii infection: An umbrella review of updated systematic reviews and meta-analyses

Objectives:

Toxoplasmosis is one of the neglected parasitic disease in humans and animals that produced via toxoplasma gondii. This study we implemented an umbrella review of all existing systematic reviews, meta-analyzing studies to apprise, and summarize seroprevalence of human toxoplasmosis in worldwide.

Methods:

The search was carried out in databases including: Pub Med, Google Scholar, Science Direct, Scopus, Web of Science, Cochrane, and global health from their start dates until December 2018 in Persian and English language. A total of 21 systematics review and meta-analysis met the inclusion criteria of umbrella review. The Q test and the I² statistic were used to evaluate heterogeneities. Quality assessment were performed and made use of the AMSTAR tool.

Results:

The estimated pooled seroprevalence of T. gondii infection in blood donors, Immunocompromised patients, childbearing age women, general population, newborns and children, pregnant women and overall was 33% (95% CI, 29.0–38.0%), 42.0% (95 CI, 34.0–49.0%), 32.0% (CI, 26.0–38.0%), 42.0% (CI, 38.0–45.0%), 4.0% (CI, 2.0–5.0%), 40.0% (CI,37.0–44.0%), and 36% (CI, 24.0–48.0%), respectively.

Conclusion:

The results of our umbrella review show a higher seroprevalence of T. gondii infection in immunocompromised patients, general population, pregnant women, blood donors, childbearing age women, and newborn groups, respectively. Routine serologic screening test and health education by primary care physicians for Toxoplasmosis is recommended to be conducted in high-risk groups in the endemic region.

Accuracy of diagnostic tests for American tegumentary leishmaniasis: a systematic literature review with meta-analyses

OBJECTIVES

To analyse the accuracy of American tegumentary leishmaniasis (ATL) diagnostic methods and evaluate the quality of the existing publications by means of a systematic review.

METHODS

Diagnostic tests evaluated in at least two studies with common reference standards were included in the sensitivity and/or specificity meta-analyses. Quality and susceptibility to bias were analysed using the QUADAS-2 and STARD tools.

RESULTS

The title and abstract of 3387 publications were evaluated after deduplication resulting from database searches. Thirty-eight studies were included in the review, and 26 of them had results inserted in meta-analyses. The diagnostic methods with the highest pooled sensitivity values were ELISA, polymerase chain reaction (PCR), indirect immunofluorescence reaction and Montenegro's intradermal reaction. Cytometry was assessed in only two studies and presented 100% sensitivity in both. Smear slide microscopy and histopathology showed low pooled values of sensitivity. For specificity, the highest pooled values were identified for PCR. High values were also identified for ELISA, except for studies in which the reference standard for defining negative participants included individuals with Chagas' disease or paracoccidioidomycosis, which also occurred for cytometry. IFR had lower specificities than ELISA. There was a predominance of case-control designs of phase 1 or 2 and only four studies were strongly recommended as evidence generators. Several reference standards were adopted, and different methods were assessed in a small number of studies.

CONCLUSION

PCR showed the highest accuracy for the diagnosis of ATL, and its use should be encouraged in clinical practice. ELISA is recommended for the screening of suspected individuals, but the possibility of cross-reactions should be considered. New validation studies for the tests evaluated in few publications and studies of phase 3 with appropriate methods are needed.

Dolichosin A, a coumestan isolated from Glycine tabacina, inhibits IL-1β-induced inflammation in SW982 human synovial cells and suppresses RANKL-induced osteoclastogenesis: From network pharmacology to experimental pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Glycine tabacina (Labill.) Benth has been used as a traditional Chinese herbal medicine for the treatment of rheumatoid arthritis (RA) and joint infection. It is also one of the sources of the renowned native herbal medicine 'I-Tiao-Gung' in Taiwan.

AIM OF THE STUDY

This study aimed to investigate anti-arthritic effects and underlying mechanisms of dolichosin A (DoA), a coumestan compound isolated from G. tabacina, by the integration of network pharmacology and experimental pharmacology.

MATERIALS AND METHODS

Putative therapeutic targets and potential pharmacological mechanisms of DoA for RA treatment were predicted by network pharmacology approach. The regulated network of DoA acting on RA was constructed using Cytoscape 3.7.1. Anti-arthritic effects of DoA and predicted mechanisms were further validated using IL-1β-induced SW982 human synovial cell model and RANKL-induced osteoclastogenesis model.

RESULTS

A regulatory network of DoA-targets-pathways-RA was successfully constructed using network pharmacology approach. In this network, 65 candidate targets of DoA related to its therapeutic effect on RA were identified and the functional enrichment analysis revealed that these candidate targets were significantly involved in 12 central signaling pathways such as PI3K/AKT pathway, MAPK pathway and osteoclast differentiation. Furthermore, we found that DoA could significantly inhibit IL-1β-induced inflammation in SW982 human synovial cells, as evidenced by the decreased levels of pro-inflammatory mediators (TNF-α, IL-6 and COX-2) and MMP-3. DoA also suppressed RANKL-induced osteoclastogenesis in vitro, as evidenced by decreased number of TRAP-positive multinucleated osteoclasts and reduced TRAP activity. Further experimental mechanism evidence confirmed the predicted results of network pharmacology that the blockade of PI3K/AKT and MAPK pathways activation was closely associated with these regulated processes of DoA.

CONCLUSIONS

Our results demonstrated that DoA exhibited strong anti-arthritic activity through suppressing PI3K/AKT and MAPK pathways activation in activated synovial cells and osteoclasts, suggesting its potential as a hopeful candidate for the development of novel agents for the prevention and treatment of RA.

Relationship between toxoplasmosis and autism: A systematic review and meta-analysis

Toxoplasma gondii (T. gondii) is a foodborne parasite that is investigated in many psychiatric diseases, such as autism spectrum disorders (ASD). Therefore, a systematic literature review was conducted searching seven electronic databases on the prevalence of T. gondii antibodies among autism patients. The current study involved sensitivity analysis, meta-regression, subgroup analysis, publication bias test, and quality assessment of studies. On the basis of the findings, the odds ratio (OR) of latent Toxoplasma infection 1.93 (95% confidence intervals (CI): 1.01-3.66) was associated with ASD risk. However, there was no relationship between acute infection and ASD 0.39 (95% CI: 0.18-0.87). The obtained results of Begg's and Egger's tests showed no publication bias (P = 0.851 and P = 0.297, respectively). The sensitivity analysis confirmed robust and stable estimates with a significant level of heterogeneity (I² = 78.1%, P < 0.000). Of the investigated patients' characteristics, only the gender variable was analyzed, indicating the combined ORs of 2.63 (95% CI: 0.29-23.63) in females and 2.62 (95% CI: 0.94-7.30) in male participants. This study showed that toxoplasmosis plays an important role as a risk factor for autism. However, further prospective investigations are highly recommended to illuminate the developmental pathways to this disorder and provide new strategies for the prevention and treatment of this disease.

Cerebral Toxoplasmosis in a Rheumatoid Arthritis Patient on Immunosuppressive Therapy

Cerebral toxoplasmosis is a life-threatening infection most commonly found in immunocompromised hosts such as acquired immunodeficiency syndrome (AIDS) or transplant patients. However, it is not known to affect patients with chronic inflammatory disorders on immunosuppressive therapy. We describe the case of a 70-year-old female with rheumatoid arthritis (RA) on chronic therapy with methotrexate and infliximab, who presented to the hospital after two weeks of right-sided weakness. Imaging revealed bilateral ring-enhancing lesions in the basal ganglia (left greater than right). A diagnosis of cerebral toxoplasmosis was made on brain biopsy. Apart from the immunosuppressive therapy and owning a cat, she had no other risk factors for developing the infection. The patient’s immunosuppressive medications were discontinued, and she was started on high-dose trimethoprim-sulfamethoxazole (TMP-SMX). Upon literature review using PubMed, we found seven other published reports on similar cases of toxoplasmosis in RA patients on immunosuppressive therapy; however, there was a lack of recommendations for diagnosis, treatment, and prophylaxis in this patient population. With the growing use of immunosuppressive therapies in chronic inflammatory disorders, further data is needed regarding the management of toxoplasmosis in these patients. This case report is an investigation of the relationship between immunosuppressive medications in RA patients and cerebral toxoplasmosis and an exploration of the available recommendations for its management.

Seroprevalence of Neospora caninum Infection in Dog Population Worldwide: A Systematic Review and Meta-analysis

PURPOSE

Neospora caninum is an obligate intracellular apicomplexan protozoan that causes neurological disorders in dogs. This systematic review and meta-analysis targeted at evaluating the worldwide seroprevalence rate of N. caninum in dogs.

METHODS

Five electronic databases, including PubMed, Scopus, Web of Science, Science Direct, and Google Scholar, until December 2018 were thoroughly searched for relevant English language articles. Papers were selected based on inclusion criteria. Data were analyzed in StatsDirect statistical software (version 2.7.9).

RESULTS

The searching process yielded a total number of 156 papers. The total prevalence (95% confidence intervals) of N. caninum infection in dog population worldwide was measured as 17.14% in data analyses (15.25-19.10). In addition, a significant association was also detected between neosporosis infection in dogs and continent, country, year, WHO regions, sample size and diagnostic method (P < 0.001).

CONCLUSION

Dogs are a matter of concern to public health officials as a source of N. caninum infection. Therefore, it is of paramount importance to provide comprehensive data and systematically analyze the prevalence of N. caninum infection in dogs. Accordingly, it is recommended that researchers carry out further studies to prevent and control neosporosis among dog population worldwide.

Is Toxoplasma gondii a potential risk factor for Alzheimer's disease? A systematic review and meta-analysis

Toxoplasmosis is a major public health concern due to neurotropic nature and role in the development of mental and behavioral disorders. Alzheimer's disease (AD) is an important nervous disease that results in the reduction of the amount of beta-amyloid plaque deposition and irreversible loss of neurons in the brain. Although a few studies evaluated the association between AD and toxoplasmosis, the present study as a systematic review and meta-analysis of published studies investigated the possible association between Toxoplasma gondii (T. gondii) and AD. A systematic literature search was conducted using seven electronic databases from the inception to 25th of November 2018 with no restriction of language that looked at toxoplasmosis (as an exposure) and AD (as a disease). The random effect model was used to determine the total odds ratio (OR) and total p-value. Generally, eight studies containing 3239 subjects (360 patients and 2879 controls) met the eligibility criteria. Then, eight articles were used for meta-analysis with respect to inclusion and exclusion criteria. The results of the meta-analysis (random effect model) showed a common OR of 1.53 (95% CI: 1.07-2.18). Despite the fact that there was no evidence of publication bias (P = 0.079) using formal statistical test, the visual inspection of the funnel graph suggested that the observed effect was fueled mainly by three studies with large effects (and large standard errors). Moreover, the file-drawer effect (i.e. publishing mainly studies with positive results) might play a role in the phenomenon. Results of this meta-analytic study suggested that T. gondii can be considered a risk factor for the development of AD and exacerbation of its symptoms. However, the number of published relevant studies is still relatively low, and the risk of the presence of publication bias is relatively high. Therefore, the investigation of the clinically important question of the possible association between toxoplasmosis and AD definitively deserves further attention.

Serological and molecular rapid diagnostic tests for Toxoplasma infection in humans and animals

Infection by Toxoplasma gondii is prevalent worldwide. The parasite can infect a broad spectrum of vertebrate hosts, but infection of fetuses and immunocompromised patients is of particular concern. Easy-to-perform, robust, and highly sensitive and specific methods to detect Toxoplasma infection are important for the treatment and management of patients. Rapid diagnostic methods that do not sacrifice the accuracy of the assay and give reproducible results in a short time are highly desirable. In this context, rapid diagnostic tests (RDTs), especially with point-of-care (POC) features, are promising diagnostic methods in clinical microbiology laboratories, especially in areas with minimal laboratory facilities. More advanced methods using microfluidics and sensor technology will be the future trend. In this review, we discuss serological and molecular-based rapid diagnostic tests for detecting Toxoplasma infection in humans as well as animals.

A systematic review and meta-analysis of the genetic characterization of human echinococcosis in Iran, an endemic country

Human echinococcosis is an infectious disease caused by tapeworms belonging to the species Echinococcus. This parasite has a worldwide distribution and is considered a neglected tropical disease by the World Health Organization. Due to the diversity of Echinococcus spp. hosts, as well as variation in geographical, climatic, and socio-ethnic conditions, the question of the strains or genotypes of Echinococcus spp. that are involved in human infections is important. The aim of this study was to provide a summary of the available data on genotypes of Echinococcus obtained from the Iranian population. Four international databases (PubMed, Scopus, Science Direct, and Web of Science) and 4 Persian databases (Magiran, Scientific Information Database, Iran Medex, and IranDoc) were searched for cross-sectional studies that reported the genotypes of Echinococcus spp. in human echinococcosis cases using molecular methods in Iran through July 2018. The Newcastle-Ottawa Scale was used to assess the quality of the selected studies. A total of 559 cases of human cystic echinococcosis were reported in the 21 included articles. The majority of cases belonged to genotype G1 (89.2%; 95% confidence interval [CI], 80.1 to 95.8), genotype G6 (8.2%; 95% CI, 2.8 to 15.9), and genotype G3 (2.3%; 95% CI, 1.1 to 3.9). Since genotype G1 of Echinococcus appears to be the most prevalent genotype affecting humans in Iran, disease control initiatives aimed at sheep intermediate hosts may be the most beneficial. In addition, educational programs and serological screening in individuals may help reduce the national impact of the disease.

The Relation between Toxocariasis and Toxoplasmosis co-infection and the presence of Rheumatoid Factor (RF) in people with hydatidosis in Southwestern Iran, from 2013 to 2018

Toxoplasmosis, toxocariasis, and hydatidosis are parasite diseases with a very human-like pathway of infection. worldwide including Iran, there are infected people with these infections. Between 2013 and 2018, serum samples were collected from 124 patients with hydatidosis and 124 serums from hydatidiosis free. Samples were examined for the presence of toxocariasis by detecting IgG antibodies, using the ELISA (Enzyme-Linked Immunosorbent Assay) IBL kit and for the presence of IgG antibodies for toxoplasmosis, using the ELISA test. Risk factors such as contact with animal pets; cats and dogs, rural or urban living, age, sex, and Presence of rheumatoid factor (RF) in serum were investigated during the study. The presence of RF was examined using an agglutination test in all confirmed cases of hydatidosis, toxocariasis, and toxoplasmosis. Of the 124 positive cases of hydatidosis, 30 (24.2%), 51 (41.1%) and 15 (12.09%) had toxoplasmosis, toxocariasis and simultaneous infection (toxoplasmosis and toxocariasis), respectively. In people with toxocariasis, rheumatoid factor was reported more frequently than in other cases. The relationship between the prevalence of rheumatoid factor in serum in people with toxocariasis was significant (41.18%). Interaction with dogs and cats and area of residence were identified as risk factors for toxocariasis (P value > 0.005). Although hydatidosis and toxocariasis are Less common infections compare with toxoplasmosis, they are considered a threat to public health in some parts of the world, including Iran. Some factors, such as habitat and interaction with animal pets (dogs and cats), play a more significant role in toxocariasis compared to toxoplasmosis in people with hydatidosis.

Toxoplasmosis seroprevalence in rheumatoid arthritis patients: A systematic review and meta-analysis

BACKGROUND

Toxoplasmosis is a cosmopolitan infection caused by an intracellular obligatory protozoan, Toxoplasma gondii. Infection to this parasite in immunocompetent patients is usually asymptomatic, but today it is believed that the infection can be a risk factor for a variety of diseases, including rheumatoid arthritis (RA). RA is an autoimmune disease and the most common type of inflammatory arthritis that is a major cause of disability. The aim of this systematic review and meta-analysis was to address the association between RA and toxoplasmosis in light of the available research.

METHODS

Based on the keywords, a systematic search of eight databases was conducted to retrieve the relevant English-language articles. Then, the studies were screened based on the inclusion and exclusion criteria. The random effect model was used to calculate the odds ratio (OR) using forest plot with 95% confidence interval (CI).

RESULTS

Overall, 4168 Individual, extracted from 9 articles were included for systematic review evaluation, with 1369 RA patients (46% positive toxoplasmosis) and 2799 individuals as controls (21% positive toxoplasmosis). Then, eight articles (10 datasets) were used for meta-analysis (1244 rheumatoid arthritis patients and 2799 controls). By random effect model, the combined OR was 3.30 (95% CI: 2.05 to 5.30) with P < 0.0001.

CONCLUSION

Although toxoplasmosis could be considered as a potential risk factor for rheumatoid arthritis, more and better quality studies are needed to determine the effect of T. gondii infection on induction or exacerbation of RA. Our study was registered at the International Prospective Register of Systematic Reviews (PROSPERO; code: CRD42017069384).