Detection of IgM and IgG anti-Toxoplasma antibodies in renal transplant recipients using ELFA, ELISA and ISAGA methods: comparison of pre- and post-transplantation status

Seroepidemiology and Associated Risk Factors of Toxoplasma gondii in Hemodialysis Patients

PURPOSE

Immunocompromised patients may be at risk for reactivation of the toxoplasmosis infection, because of defection in cell-mediated immunity. Therefore, early diagnosis would be highly desirable in these individuals. This case-control study was designed to increase information about toxoplasmosis in hemodialysis (HD) patients in Guilan province, Iran.

METHODS

The study was performed among 150 patients and 150 controls referred to hospitals of Guilan University of Medical Sciences during 2018-2019. Questionnaire forms, including demographic and epidemiological information, were completed. Peripheral blood samples were taken for serum separation and were collected into tubes and then kept at - 20 °C until use. IgG and IgM antibodies to Toxoplasma gondii were detected by a commercial ELISA kit. Accordingly, IgG absorbance levels < 9 were considered negative, 9-11 was considered borderline, and > 11 was positive; IgM absorbance levels < 0.9 were considered negative, 0.9-1.1 was assumed to be borderline, and > 1.1 was positive.

RESULTS

Throughout the study, 72.0% of HD patients and 64.7% of the control group were positive for anti-Toxoplasma IgG antibody subsequently. 2% of HD patients and 0.7% of the control group were positive for anti-Toxoplasma IgM antibody and these difference weren't significant between control and ones with HD (P > 0.05). There was no significant difference between dialysis duration factor and the seropositivity rate. Seroprevalence of T. gondii infection did not vary significantly with age, educational level, residence and presence of a cat at home. On the contrary, seroprevalence varied significantly with gender and consumption of raw vegetables.

CONCLUSION

Because of the high percentage of positivity for Toxoplasma IgG antibodies in hemodialysis patients, we suggest a periodically screening program to carry out for monitoring and evaluating the possible dissemination of toxoplasmosis during hemodialysis.

Effect of Imiquimod on Tachyzoites of Toxoplasma gondii and Infected Macrophages in vitro and in BALB/c Mice

Treatment for toxoplasmosis is not completely successful because of their unwanted side effects, and new treatments are needed. Imiquimod has ability to moderate immune response and used to treat a wide variety of infections and tumors. The aim of the present study was to evaluate the effect of imiquimod on the tachyzoites of T. gondii and infected macrophages in vitro and in BALB/c mice. The viability of T. gondii was assessed in the presence of various concentrations of imiquimod by direct counting after 6 and 24 h. The MTT assay was used to identify the viability of uninfected macrophages. The apoptotic effects were determined with flow cytometry on the tachyzoites and infected macrophages. For evaluation of parasite load in pre-treatment or post-treatment of macrophages Quantitative real time PCR (qPCR) was performed. For in vivo experiments, BALB/c mice received imiquimod before and after challenge with parasites. The mortality rate of mice, parasite numbers in spleen, and the INF-γ and IL-4 cytokine levels in spleen lymphocytes were evaluated. Imiquimod demonstrated anti-Toxoplasma effects by reducing the number of tachyzoites. The results of flow cytometry for drug-treated tachyzoites showed that apoptosis did not rise significantly relative to the control group (p < 0.05). Moreover, apoptosis was enhanced in infected macrophages as the concentration of imiquimod was reduced. The parasitic burden in imiquimod pretreated macrophages was significantly lower than those treated after infection (p < 0.01). A marked reduction was observed in survival rate, parasite load and INF-γ level in BALB/c mice that received imiquimod before parasitic challenge relative to those received drug after parasitic challenge (p < 0.01). Overall, imiquimod in the pretreated group had greater anti-Toxoplasma effects than imiquimod in posttreated group in vitro and in vivo. imiquimod may be considered as a candidate for use against Toxoplasmosis both therapeutically and prophylactically.

Study of toxoplasmosis and toxocariasis in patients suffering from ophthalmic disorders using serological and molecular methods

Introduction

Toxoplasma gondii is an intracellular protozoan parasite that can cause ocular toxoplasmosis with most complications such as retinal detachment. Toxocara parasite, round worm, found in dogs and cats appears as larva migrans in humans can cause serious ocular complications such as debilitating vision loss.In Khuzestan province, southwest of Iran, T. gondii infection has been reported to be significant but toxocariasis was rare. However, the frequency of ocular toxoplasmosis and toxocariasis has not been studied in this area. The aim of this study was to evaluate the ocular toxoplasmosis and ocular toxocariasis using serological and molecular methods.

Method

In this case control study, 310 patients were identified by ophthalmologist as ocular toxoplasmosis and then 5 cc of venous blood samples were taken from each of them. Serum samples and buffy coat were prepared and ELISA was used to detect IgG and IgM anti-Toxoplasma antibodies and the molecular PCR was used to detect Toxoplasma DNA parasite in buffy coats. ELISA test was used to detect of IgG anti-Toxocara antibodies.

Results

Totally, for ocular toxoplasmosis, 130 (41.93%) of 310 patients were positive by ELISA, of them 121 (39%) IgG positive and nine (2.9%) IgM positive were diagnosed. Of 121 cases with IgG⁺, 119 (98.35%) were diagnosed with high IgG avidity indicating chronic phase of the infection. For ocular toxocariasis evaluation, antibodies against Toxocara were not detected in any of the samples. By PCR molecular method, 11 out of 310 patients (3.54%) had T. gondii DNA in the blood. In control, in total, 21 cases were detected positive by serology method, which showed a significant difference with the results of the case group(P < 0.05).By PCR method, only three cases showed positive which also indicated significant difference with result of case group (3 vs 9) (P < 0.05). In the control group, also no anti-toxocara antibodies were found.

Conclusion

It can be concluded that T. gondii in Khuzestan province as the etiologic agent of ocular toxoplasmosis and physicians should consider diagnostic methods for identifying the infection when they visit the patients.

Toxoplasma gondii: Preventive and therapeutic effects of morphine and evaluation of treatment parameters of tachyzoites and infected macrophages in vitro and in a murine model

Common medicines for the treatment of toxoplasmosis have limited efficacy and unwanted side effects. Opiates can effect both innate and cell-mediated immunity and stimulate the immune responses in different parasitic infections. In this work, preventive and therapeutic effects of morphine were evaluated on the tachyzoites of Toxoplasma gondii and infected macrophages in vitro and in a murine model. Different concentrations of morphine (0.1 and 0.01 μg/ml) were evaluated on mortality rate of T. gondii by direct counting after 3 and 24 hours. The cytotoxic and apoptotic effects of these drugs were measured by the MTT assays and flow cytometry analysis, respectively. The same procedures were assessed in T. gondii-infected macrophages. The parasite loads were determined using quantitative polymerase chain reaction (qPCR). For in vivo assessment, BALB/c mice treated with morphine before or after infection with tachyzoites. The survival rate of animals, parasite load in the spleen, and the IFN-γ and IL-4 cytokines levels were measured. Morphine was effective on tachyzoites of T. gondii and had a reverse relationship with its concentration. The results of flow cytometry showed that the toxic effects of morphine on tachyzoites after 3 hours was not statistically significant (p<0.05). Also, apoptosis in infected MQs rose with a decreasing concentration of morphine. The parasitic load in MQs treated with morphine before infection was lower than that in cells treated after infection and the differences were statistically significant (p<0.01). In mice that received morphine before infection, survival rate, parasite load and the IFN-γ level were significantly lower than in mice treated after infection (p<0.01). The results of this study have shown that morphine in the pre-treatment group had higher anti-Toxoplasma activity than morphine in post-treatment in vitro and in murine model.

Toxoplasma infection in kidney donors and transplant recipients from Western Mexico: A one-year follow-up

PURPOSE

Solid organ transplant recipients are highly susceptible to Toxoplasma gondii infection. We aimed to describe the 12-month follow-up risk of seroconversion in renal transplant recipients.

METHODOLOGY

Anti-T gondii antibodies were investigated in donors and recipients of renal transplants. In donors, anti-T gondii were evaluated before transplantation. In recipients, anti-T gondii were monitored over a 12-month period to evaluate potential seroconversion or reactivation. IgG and IgM anti-T gondii antibodies were investigated through enzyme immunoassay and Western blot. Molecular diagnosis was performed on peripheral blood leukocytes using PCR to amplify fragments corresponding to the T gondii B1 gene and the repetitive 529-bp element.

RESULTS

The basal frequency of seropositive IgG anti-T gondii antibodies was higher in donors than in recipients (38.4% vs 25.2%; P = .03). During the 12-month follow-up, the accumulated seroconversion to IgG and IgM antibodies was 3/99 (3.0%), and the accumulated reactivation was 11/99 (11.0%). None of the samples exhibited positivity to T gondii DNA.

CONCLUSIONS

This study showed that there is an increased risk of seroconversion or reactivation in renal transplant recipients over a 12-month follow-up. Our data suggest that prophylaxis with trimethoprim and sulfamethoxazole effectively prevented toxoplasmosis, since neither T gondii DNA nor clinical toxoplasmosis was detected.

Rhomboid antigens are promising targets in the vaccine development against Toxoplasma gondii

Toxoplasma gondii (T. gondii) is an obligate intracellular parasite with worldwide distribution. It is estimated that near one-third of the people around the globe are latently seropositive for the parasite. Since the current common drugs are incapable in the elimination of parasites within tissue cysts, the development of an effective vaccine has high priority for researchers to limit the infection. During recent years, non-stop efforts of scientists have made great progress in the identification and development of T. gondii candidate vaccines. However, there is a lack of a commercially licensed vaccine for human application yet. Rhomboid proteases (ROMs) are a class of serine proteases that have an important role in the invasion of the parasites that can be considered as a new target for vaccine strategy. They also play critical roles in mitochondrial fusion and growth factor signaling, allowing the parasite to completely enter into the host cell. In the current review, we have summarized the recent progress regarding the development of ROM-based vaccines against acute and chronic T. gondii infection in animal models.

Serological and Molecular Diagnosis of Toxoplasma gondii Infections in Thalassemia Patients

BACKGROUND

This study aimed to the serological and molecular diagnosis of Toxoplasma gondii infections and related risk factors in patients with thalassemia major and healthy controls.

METHODS

This case-control study was performed in Shahrekord University of Medical Sciences, Shahrekord, west of Iran from Jan 2014 to Jan 2015. Overall, 235 patients with thalassemia major and 235 healthy controls were enrolled. Assessment of anti-Toxoplasma antibodies in sera samples was performed using commercial ELISA kits. In order to the molecular investigate of T. gondii in blood samples, a relatively new molecular assay, LAMP technique based on Toxoplasma SAG1 gene was conducted for the first time. The specificity of LAMP outer primers for the T. gondii detection was confirmed by sequencing the purified PCR product.

RESULTS

51.9% of thalassemia patients and 34.8% of healthy controls were positive for anti-Toxoplasma IgG antibodies, which the difference was statistically significant (P<0.01). In terms of anti-Toxoplasma IgM antibody, 3.4% of thalassemia patients and 2.1% of healthy individuals were positive, which the difference was not statistically significant (P=1). Based on SAG1-LAMP, 9.78% of the thalassemia patients and 5.95% of healthy controls were positive for T. gondii DNA, which the difference was not statistically significant (P≤0.230).

CONCLUSION

Thalassemia patients, probably due to repeated blood transfusion and consequently, immune deficiency, are at risk of transmitting Toxoplasma infection more than healthy people. Therefore, screening of Toxoplasma infection in blood transfusion centers may be effective in the prevention of toxoplasmosis in these patients.

Diagnosis of Acute Toxoplasmosis by IgG and IgM Antibodies and IgG Avidity in Pregnant Women from Mashhad, Eastern Iran

BACKGROUND

We aimed to evaluate the diagnosis of acute toxoplasmosis by IgG avidity test in pregnant women.

METHODS

In this cross-sectional study, 250 blood samples were collected from pregnant women with the first month of their pregnancy referring to health centers of University in Mashhad during 2016. Samples were centrifuged at 3000 rpm for 5 min for separation of serum and were kept in the -20 until use. To detection of acute and chronic toxoplasmosis, anti-Toxoplasma antibodies (IgG and IgM, and IgG avidity tests were performed using ELISA. Then, data analyzed using SPSS software by Frequency, Pearson Chi-Square, Likelihood Ratio, and Exact tests. And P<0.05 was statistically considered as significant.

RESULTS

Total prevalence of IgG and IgM was 23.2% and 7.2%, respectively. A significant correlation was observed between the mean age and IgG level (P<0.05). It was not found any correlation between the history of raw meat consumption, cats keeping, education, and residency site. Moreover, 16 people (6.4%) had IgM antibody, of which, 10 cases (62.5%) with low avidity for IgG and 1 people (6.2%) with moderate avidity and 5 cases (31.3%) with high avidity for IgG. Moreover, 76% of pregnant women were seronegative.

CONCLUSION

More than half of the women (62.5%) with positive IgM antibody in their serum had a low avidity for IgG which revealed an acute infection among pregnant women. Toxoplasma infection should be considered as an important factor that affects the pregnancy and IgG avidity as an important test for screening the women who need the treatment.

A systematic review and meta-analysis of the prevalence of toxoplasmosis in hemodialysis patients in Iran

OBJECTIVES

Toxoplasmosis is a parasitic disease that occurs worldwide, with a wide range of complications in immunocompromised patients. This systematic review and meta-analysis was performed to evaluate the seroprevalence of Toxoplasma gondii among patients undergoing hemodialysis in Iran.

METHODS

We searched English and Persian databases for studies reporting T. gondii seroprevalence in Iranian hemodialysis patients through December 31, 2017. Inclusion and exclusion criteria were applied.

RESULTS

A total of 10 studies containing 1,865 participants (1,048 patients and 817 controls) met the eligibility criteria. Immunoglobulin G (IgG) antibodies against T. gondii were found in 58% (95% confidence interval [CI], 46 to 70) of hemodialysis patients and 40% (95% CI, 31 to 50) of healthy controls, while immunoglobulin M (IgM) antibodies were found in 2% (95% CI, 0 to 6) of hemodialysis patients and 0% (95% CI, 0 to 1) of healthy controls. The meta-analysis showed that hemodialysis patients were significantly more likely to be seropositive for IgG (odds ratio [OR], 2.04; 95% CI, 1.54 to 2.70; p<0.001) and IgM (OR, 2.53; 95% CI, 1.23 to 5.22; p<0.001) antibodies against T. gondii infection than healthy individuals.

CONCLUSIONS

The current study revealed a high prevalence of T. gondii infection in hemodialysis patients. Since hemodialysis patients are immunocompromised and T. gondii can cause serious clinical complications, we recommend that periodic screenings for T. gondii infection should be incorporated into the routine clinical care of these patients.

Detection of anti-Toxoplasma gondii antibodies in chronic myeloid leukemia and acute myeloid leukemia patients

IN:

Background and Aim: Infection of Toxoplasma gondii is a worldwide distribution. Toxoplasmosis in patients who are immunocompromised by virtue of underlying leukemia disease has received relatively little attention. This study was aimed to evaluate IgG and IgM antibodies of T. gondii and to minimize the role of T. gondii and opportunistic infection complication at the early stage of infection in leukemia patients.

Materials and Methods:

The purpose of this assay was to measure anti-T. gondii IgG and IgM antibodies by enzyme-linked immunosorbent assay (ELISA) technique in leukemia patients.

Results:

IgG antibodies against T. gondii were detected by ELISA in 96 (56.4%) leukemia patients and 72 (42.4%) control group. IgM antibodies were found in 10 patients (5.9%) with leukemia and 3 (1.8%) in the corresponding.

Conclusion:

Our finding indicated that leukemia patients under immunosuppressive condition should not be neglected. Toxoplasmosis in leukemia patients as a main risk factor is considered, meanwhile in some patients, due to possibility of the presence of secondary infection that leads to severe toxoplasmosis.

Toxoplasma gondii Infection in Immunocompromised Patients: A Systematic Review and Meta-Analysis

Toxoplasma gondii has been suggested as an important opportunistic pathogen in immunocompromised patients. We conducted a global meta-analysis to assess the prevalence and odds ratios (ORs) of T. gondii infection in immunocompromised individuals. Electronic databases were reviewed for T. gondii infection in HIV/AIDS patients, cancer patients, and transplant recipients, and meta-analyses were conducted to calculate overall estimated prevalence and ORs using random or fixed-effects models. Totally, 72 eligible studies were included. The estimated pooled prevalence of T. gondii infection in immunocompromised patients and the control was 35.9 and 24.7% (p < 0.001), with an OR of 2.24, i.e., 42.1 and 32.0% for HIV/AIDS patients and the control (p < 0.05), 26.0 and 12.1% for cancer patients and the control (p < 0.001), and 42.1 and 34.5% for transplant recipients and the control (p > 0.05), whose estimated pooled ORs were 1.92 (95% CI, 1.44-2.55), 2.89 (95% CI, 2.36-3.55), and 1.51 (95% CI, 1.16-1.95), respectively. This study is the first to demonstrate that the immunocompromised patients are associated with higher odds of T. gondii infection, and appropriate prevention and control measures are highly recommended for these susceptible populations.

Seroprevalence of Toxoplasma gondii in the Iranian pregnant women: A systematic review and meta-analysis

Toxoplasmosis is a common and serious parasitic disease with high prevalence and global distribution in human and other warm-blooded vertebrates. Though the infection of Toxoplasma gondii is usually asymptomatic in healthy people, it can lead to severe pathological effects to the fetus of infected women and immunocompromised patients. So pinpointing the risk factors and control procedures are of important works among these populations. In order to reach this goal, we conducted a systematic review and meta-analysis to identify the seroprevalence rate of T. gondii infection among Iranian pregnant women population to achieve a comprehensive explanation of the disease condition in Iran for future use. English electronic databases (PubMed, Science Direct, Scopus, Ovid and Cochrane) and Persian language databases (Scientific Information Database, Iran Medex, Magiran and Iran Doc) were searched. Furthermore, the proceedings of Iranian parasitology congresses were explored manually. Our review resulted in a total of 50 publications meeting the inclusion criteria during Jan 1990-June 2015. Totally, 20221 women had been tested during this period of which 7724 women had seropositivity for IgG. According to results of heterogeneity test, either Der Simonian and Laird's random-effects method or Mantel-Haenszel's fixed-effects method were used to pool the estimations. Weighted overall prevalence of toxoplasmosis in pregnant women were obtained using random-effects model, which was estimated 41% (95% CI=36-45%). Also IgG and IgM antibodies was obtained 38% (95% CI=34-42%) and 4% (95% CI=3-5%), respectively. The highest and the lowest seroprevalence of toxoplasmosis in five geographical zones of Iran were observed in South 53% (95% CI=30-77%) and East 33% (95% CI=23-42%), respectively. In order to detect publication bias, Egger's regression test was done which revealed that publication bias might not have a significant influence on overall prevalence estimate (P=0.89). Multivariate analysis showed that there's a statistically significant correlation between toxoplasmosis and two risk factors including "place of residence" (P=0.005) and "contact with cat" (P=0.002). There was no significant difference between toxoplasmosis and the other surveyed risk factors. It is highly recommended to further study for the aim of better disease management and developing more efficient diagnostic tests.

Toxoplasmosis in Blood Donors: A Systematic Review and Meta-Analysis

Transfusion-transmissible infections include pathogens that may cause severe and debilitating diseases. Toxoplasmosis is a cosmopolitan neglected parasitic infection that can lead to severe complications including death in immune-compromised patients or following infection in utero. Multiple studies have demonstrated the transmission of Toxoplasma gondii by blood transfusion. The objective of this review was to comprehensively assess the seroprevalence rate of Toxoplasma in blood donors from a worldwide perspective. Seven electronic databases (PubMed, Science Direct, Web of Science, Scopus, Cochrane, Ovid, and Google Scholar) were searched using medical subject headings terms. A total of 43 records met the inclusion criteria in which 20,964 donors were tested during the period from January 1980 to June 2015. The overall weighted prevalence of exposure to toxoplasmosis in blood donors was 33% (95% confidence interval [CI], 28%-39%). The seroprevalences of immunoglobulin (Ig)M and both IgG and IgM antibodies were 1.8% (95% CI, 1.1%-2.4%) and 1.1% (95% CI, 0.3%-1.8%), respectively. The highest and the lowest seroprevalences of toxoplasmosis were observed in Africa (46%; 95% CI, 14%-78%) and in Asia (29%; 95% CI, 23%-35%), respectively. Brazil (75%) and Ethiopia (73%) were identified as countries with high seroprevalence. Because positive serology does not imply infectiousness and because seroprevalence is high in some nations, a positive serology test result alone cannot be used as an effective method for donor screening. Future research for methods to prevent transfusion-transmitted toxoplasmosis may derive benefit from studies conducted in areas of high endemicity.

Experimental infection with the Toxoplasma gondii ME-49 strain in the Brazilian BR-1 mini pig is a suitable animal model for human toxoplasmosis

Toxoplasma gondii causes toxoplasmosis, a worldwide disease. Experimentation with pigs is necessary for the development of new therapeutic approaches to human diseases. BR-1 mini pigs were intramuscularly infected with T. gondii with tachyzoites (RH strain) or orally infected with cysts (ME-49 strain). Haematology and serum biochemistry were analysed and buffy coat cells were inoculated in mice to determine tachyzoite circulation. No alterations were observed in erythrocyte and platelet values; however, band neutrophils increased seven days after infection with ME-49. Serology of the mice inoculated with pig blood leucocytes revealed circulating ME-49 or RH strain tachyzoites in the pigs' peripheral blood at two and seven or nine days post-infection. The tachyzoites were also directly observed in blood smears from the infected pigs outside and inside leucocytes for longer periods. Alanine-aminotransferase was high at days 21 and 32 in the RH infected pigs. After 90 days, the pigs were euthanised and their tissue samples were processed and inoculated into mice. The mice serology revealed the presence of parasites in the hearts, ileums and mesenteric lymph nodes of the pigs. Additionally, cysts in the mice were only observed after pig heart tissue inoculation. The infected pigs presented similar human outcomes with relatively low pathogenicity and the BR-1 mini pig model infected with ME-49 is suitable to monitor experimental toxoplasmosis.

Detection of toxoplasmosis in patients with end-stage renal disease by enzyme-linked immunosorbent assay and polymerase chain reaction methods

Toxoplasmosis caused by Toxoplasma gondii is an opportunistic infection. In healthy individuals, the infection is largely asymptomatic, but in immunocompromised people the parasite can become widely disseminated, causing severe toxoplasmosis. In patients undergoing haemodialysis, the phagocytic process shows a highly significant impairment. Therefore, this study aimed to investigate toxoplasmosis in patients with end-stage renal disease (ESRD) undergoing haemodialysis in Ahvaz hospitals, southwest of Iran. A total of 280 patients and 100 healthy subjects participated in this study. The presence of serum IgM and IgG antibodies against T. gondii was detected by ELISA and the presence of Toxoplasma parasites in whole blood was evaluated by GRA6 PCR. Anti-T. gondii IgG antibodies were detected in 82 (29.3 %) haemodialysis patients and 26 (26 %) controls. In addition, anti-T. gondii IgM antibodies were detected in 7.9 % of patients and in 4 % of controls. For both the antibodies, the differences were statistically significant (P < 0.05). PCR was performed with DNA extracted from blood samples of all patients and controls. PCR gave positive results with four of the 280 blood samples from patients but none for the control blood samples. The results revealed a high percentage of positivity for Toxoplasma antibodies in patients with ESRD undergoing haemodialysis and also confirmed the parasite in whole blood, indicating disseminated infection in these patients. Patients undergoing dialysis have a higher rate of active infection with Toxoplasma likely due to reactivation of a chronic infection. Thus, parasitological examinations of ESRD patients should be periodically carried out for monitoring and evaluating the possible dissemination of toxoplasmosis during haemodialysis.