Ocular Toxoplasmosis Patients Research Articles

The Decreased Treg Cells Number Associated with Retinal Lesion Size in Ocular Toxoplasmosis.

The imbalance of the immune response is an important factor contributing to the incidence of ocular toxoplasmosis (OT). Regulatory T cells (Treg) play a key role in maintaining the balance between Th1 and Th17 immune responses, while interleukin-27 (IL-27) levels are related to the differentiation of Th17 cells. This study analyzes the differences in the number of Treg cells and the level of IL-27 between OT patients and seropositive individuals without ocular lesions and its correlation with retinal lesion size. This analytic observational study, conducted for 8 months, involved 11 OT patients and 10 seropositive individuals without ocular lesions. All subjects underwent a comprehensive ophthalmological examination. Retinal lesions were documented by fundus photographs and the size was measured using Digimizer 4.2.2.0 software. Isolation of peripheral blood mononuclear cells (PBMC) was performed to measure the number of Treg cells using flow cytometry and interleukin-27 levels were assessed using the Sandwich enzyme-linked immunosorbent assay (ELISA) technique. Data were analyzed with SPSS. The number of Treg cells in the OT group (47.16 ± 15.66%) was lower than in the seropositive group without the ocular lesions (62.86 ± 17.08%) (p = 0.029). The serum IL-27 levels in the OT group were not significantly different from the seropositive group without the ocular lesions (p = 0.360). The number of Treg cells was significantly related to retinal lesion size (p = 0.043), with a correlation coefficient of -0.648, indicating a strong and inverse correlation. There was no significant correlation between serum IL-27 levels and retinal lesion size (p = 0.556). Ocular toxoplasmosis patients have a low number of Treg cells that are inversely related to the retinal lesion size. The size of the retinal lesion increases as the number of Treg cells decreases.

Elevated interleukin-10 levels in patients with ocular toxoplasmosis.

In elderly patients, ocular toxoplasmosis is one of the most common etiologies of uveitis, which should be differentially diagnosed from ocular lymphoma, another common pathology of uveitis in older adults. The high level of interleukin (IL)-10 and an IL-10/IL-6 ratio higher than 1 (>1.0) are helpful parameters to diagnose ocular lymphoma. In this study, we used aqueous humor samples to detect 4 cases of ocular toxoplasmosis in patients with high levels of IL-10 and an IL-10/IL-6 ratio higher than 1. Our results show that ocular toxoplasmosis may be associated with increased cytokine levels in aqueous humor.

Clinical Characteristics of Ocular Toxoplasmosis Patients

Toxoplasma gondii infection causes posterior uveitis and blindness. The diagnosis of ocular toxoplasmosis is based on typical clinical findings accompanied by positive anti-Toxoplasma serology. This study aims to see the clinical characteristics of ocular toxoplasmosis patients. Cross-sectional observational descriptive research is done. This study used 2019-2021 medical records from RSUP Dr. Mohammad Hoesin Palembang patients. The highest incidence of ocular toxoplasmosis at RSUP Dr. Mohammad Hoesin Palembang in 2019-2021 occurred in 2021 (54.5%). The most common age range found in this case is the age group of 0-19 years (45.5%) and the majority are women (72.7%). The majority of patients are out of work (45.5%) and live outside Palembang (81.8%). The most lateralization was found in the right eye (63.6%). The most commonly complained clinical symptom is blurred vision (90.9%). Clinical signs were found lesions of retinochoroiditis in the macular (45,5%), in the extramacular (18,2%), chorioretinal scar (90,9%), vitritis (54,5%), decreased visual acuity (100%), and increased IOP (36,4%). Anti-Toxoplasma IgG was found positive in all patients. The highest incidence of ocular toxoplasmosis was found in 2021. The most commonly complained clinical symptom is blurred vision and the most commonly found clinical sign is a decrease in visual acuity.

Comparative study of oxidative stress and antioxidative markers in patients infected with Toxoplasma gondii.

Recently, oxidative stress and antioxidative compounds have been described as potential biomarkers. However, there is no consensus on the most appropriate oxidative and antioxidative biomarkers for patients with Toxoplasma gondii. In the present study, we evaluated the levels of lipid, protein, DNA oxidative damage and antioxidants in samples from patients infected with T. gondii with and without ocular toxoplasmosis. The levels of MDA, TBARS, micronuclei, carbonyl, GSH, vitamin C and vitamin E were measured on samples from 8 patients positive for T. gondii antibodies with ocular toxoplasmosis (OT), 20 patients positive for T. gondii antibodies without ocular toxoplasmosis (non OT), and 12 healthy individuals negative for T. gondii antibodies. The levels of MDA, TBARS, carbonyl and micronuclei were significantly higher in non OT patients, while MDA and TBARS levels were lower in OT patients. In contrast, the antioxidative factors, GSH and vitamin E levels were significantly lower in non OT patients, while vitamin C was lower in non OT and OT patients. Additionally, non OT patients were indicated to be high producers of oxidative markers (TBARS, MDA, micronuclei and carbonyl), while control group was indicated to be high producer of antioxidative markers (GSH, vitamins C and E). However, OT patients were not found as high producers of oxidative nor antioxidative markers. Our results provide a starting point of possible markers to better understand the disease pathogenesis in patients infected with T. gondii. Additional studies are needed to clarify the potential contribution of oxidative and antioxidative markers in these patients population.

Distinguishing swept-source optical coherence tomography findings in active toxoplasmic retinochoroiditis.

To define the swept-source optical coherence tomography (SS-OCT) features which distinguish ocular toxoplasmosis (OT) from other forms of retinochoroiditis. This is a prospective diagnostic study enrolling 43 eyes of 43 patients with active toxoplasmic (TOXO) retinochoroiditis matched to 54 eyes (54 lesions) with non-TOXO retinochoroiditis evaluated by structural SS-OCT. The finding of retinal hyper-reflective round deposits, sub-lesional choroidal thickening, and sub-lesional retinal pigment epithelium elevation were more likely to be found in TOXO lesions with a positive likelihood ratio of 45.2 (95% CI: 6.45-316.56), 23.86 (95% CI: 6.09-93.36), and 9.79 (95% CI: 4.22-22.7), respectively. The presence of each of these findings was associated with a high level for positive predictive value (PPV) (88.63-97.29), negative predictive value (NPV) (88.3-92.45), sensitivity (83.72-90.69), and specificity (90.74-98.14). Two-parameter model binary logistic regression suggested that sub-lesional retinal pigment epithelium elevation and sub-lesional choroidal thickening were significant predictors of the diagnosis of OT (Wald = 11.905, p < 0.001; Wald = 14.881, p < 0.001; respectively). By adding hyper-reflective round deposits along the posterior hyaloid or the retinal surface the model improved its performance with very good diagnostic accuracy with area under the curve (AUC) values of 0.96 (95% CI: 0.9-0.99) for two parameters model and 0.98 (95% CI: 0.93-0.99) for the three parameters model. Our results show that three OCT findings including retinal hyper-reflective round deposits, sub-lesional choroidal thickening, and sub-lesional retinal pigment epithelium elevation are more likely to occur in OT patients as compared with non-OT patients.

Sulfadiazine plasma concentrations in women with pregnancy-acquired compared to ocular toxoplasmosis under pyrimethamine and sulfadiazine therapy: a case\u2013control study

BackgroundDosing recommendations for the treatment of pregnancy-acquired toxoplasmosis are empirical and widely based on experimental data. There are no pharmacological data on pregnant women with acute Toxoplasma gondii infection under treatment with pyrimethamine (PY) and sulfadiazine (SA) and our study intends to tighten this gap.MethodsIn this retrospective case–control study, we included 89 pregnant women with primary Toxoplasma infection (PT) treated with PY (50 mg first dose, then 25 mg/day), SA (50 mg/kg of body weight/day), and folinic acid (10–15 mg per week). These were compared to a group of 17 women with acute ocular toxoplasmosis (OT) treated with an initial PY dose of 75 mg, thereafter 25 mg twice a day but on the same SA and folinic acid regimen. The exact interval between drug intake and blood sampling and co-medication had not been recorded. Plasma levels of PY and SA were determined 14 ± 4 days after treatment initiation using liquid chromatography–mass spectrometry and compared using the Mann–Whitney U test at a p < 0.05 level.ResultsIn 23 PT patients (26%), SA levels were below 20 mg/l. Fifteen of these 23 patients (17% of all patients) in parallel presented with PY levels below 700 µg/l. Both drug concentrations differed remarkably between individuals and groups (PY: PT median 810 µg/l, 95% CI for the median [745; 917] vs. OT 1230 µg/l [780; 1890], p = 0.006; SA: PT 46.2 mg/l [39.9; 54.4] vs. OT 70.4 mg/l [52.4; 89], p = 0.015) despite an identical SA dosing scheme.ConclusionsSA plasma concentrations were found in the median 34% lower in pregnant women with PT compared to OT patients and fell below a lower reference value of 50 mg/l in a substantial portion of PT patients. The interindividual variability of plasma concentrations in combination with systematically lower drug levels and possibly a lower compliance in pregnant women may thus account for a still not yet supportable transmission risk. Systematic drug-level testing in PT under PY/SA treatment deserves to be considered.

Ocular toxoplasmosis associated with up-regulation of miR-155-5p/miR-29c-3p and down-regulation of miR-21-5p/miR-125b-5p

Ocular toxoplasmosis (OT) is one of the most common manifestations of Toxoplasma gondii infection and can be related with congenital or acquired infections. OT cause posterior uveitis that cause serious sequelae as complete loss of vision. microRNAs (miRNAs) are small non-coding RNAs, which have regulatory roles in cells by silencing messenger RNA. This study evaluated gene expression of miR-155-5p, miR-146a-5p, miR-21-5p, miR-29c-3p and miR-125b-5p in plasma of 51 patients with ocular toxoplasmosis (OT Group), 26 individuals with asymptomatic toxoplasmosis (AT Group), and 25 healthy individuals seronegative for toxoplasmosis (NC Group). Peripherical blood samples were collected in tube with EDTA for plasma isolation, laboratorial diagnosis for toxoplasmosis and RNA extraction. miRNA expression of each sample was performed by qPCR and values were expressed in Relative Quantification (RQ). Results showed that miR-155-5p and miR-29c-3p were up-expressed in OT patients than AT individuals. On the other hand, miR-21-5p and miR-125b-5p were down-expressed in OT patients. Differences were statistically significant. miR-146a-5p expression was similar in OT patients and AT individuals, without significant difference. In addition, comparative analysis for miRNA levels between AT and OT groups confirms these results. So far, this is the first study to evaluate circulating miRNA levels in ocular toxoplasmosis. These findings may contribute to further studies evaluating the exact role of these miRNAs in the course of infection, which may help in understanding the complex parasite-host interaction and future use in diagnosis, prognosis and therapeutic control in ocular toxoplasmosis.

Serological and molecular approaches in clinical diagnosis of ocular toxoplasmosis in Iran.

Background: Toxoplasma gondii (T. gondii) is the most common parasite that can lead to a disease called toxoplasmosis. In this study, serological and molecular complementary tests have been conducted to detect or diagnose this parasite. Methods: A total of 71 patients with clinical symptoms of ocular toxoplasmosis and 20 patients with other ocular infections were evaluated. Serum and buffy coat samples were collected and tested using enzyme-linked immunosorbent assay (ELISA) and nested polymerase chain reaction (nPCR) assessments. Superficial T. gondii B1 gene was evaluated in PCR. The ocular toxoplasmosis patients were followed-up 2 weeks after the first sampling and 4 weeks following the first laboratory testing. The main outcome measures were the efficiency of the diagnostic procedure and positive and negative predictive values (PPV and NPV). Results: Overall, of the samples, 69% were PCR+, IgG+, and IgM-, and 4.2% showed PCR+, IgG+, and IgM+. In the first follow-up, after 2 weeks, from the 41 referred patients, 29 (70%) showed PCR+, IgG+, and IgM-, which confirmed the results of the first sampling. In the second follow-up, 9 (47%) patients were PCR+, IgG+, and IgM-. A correlation was observed between the first referral and the follow-ups. Also, from 71 patients, diagnosed clinically as ocular toxoplasmosis, the disease was confirmed in 73.2% and 26.8% of those suffering from other ocular infections. Of the 20 control group samples, 55% showed PCR-, IgG+, and IgM-. The sensitivity, specificity, negative and positive predictive values, and negative and positive likelihoods were analyzed for IgG and IgM antibodies and for PCR using ELISA method. Conclusion: As the ophthalmologic signs of T. gondii may be mimicked by other infections, clinical methods may be complemented by laboratory approaches for a definite diagnosis. This would assist clinicians to achieve timely diagnosis and successful therapy and to control the infection.

Sero-molecular detection, multi-locus genotyping, and clinical manifestations of ocular toxoplasmosis in patients in northwest Iran.

Our goal was to use molecular techniques to verify and characterise clinical diagnoses of ocular toxoplasmosis. Clinical cases were evaluated against IgM and IgG Toxoplasma antibodies, and IgG avidity was tested. B1 gene was assessed for molecular detection, and multi-locus genotyping were conducted to type Toxoplasma infections. A cross-sectional study was conducted in 33 patients with suspected active ocular toxoplasmosis. Patients were examined by an ophthalmologist and clinical manifestations were recorded. Toxoplasma gondii IgG and IgM from serum samples were analysed by chemiluminescence immunoassay and ELISA. Acute vs chronic infection was evaluated by IgG avidity testing. Molecular diagnosis of T. gondii infection targeted the B1 gene, and the T. gondii genotype was determined by amplification of the GRA6, SAG2, SAG3, BTUB and APICO loci. The correlation of age, gender, occupation, education, contact with cats or soil, and the consumption of undercooked meat with the incidence of ocular toxoplasmosis was evaluated. Twenty-eight patients (84.8%) were seropositive, two (6%) were both IgG and IgM positive, while one (3%) showed IgG avidity <40%. Molecular testing confirmed toxoplasmosis in 27 patients (81.8%). Chorioretinal scarring (p=0.014) and posterior uveitis (p=0.004) was significantly associated with ocular toxoplasmosis patients. Multi-locus genotyping showed genotype I. Ocular toxoplasmosis showed no significant correlation with gender, age, behaviours, occupation or education. Clinical manifestations, serological and molecular detection of Toxoplasma were highly correlated in the diagnosis of ocular toxoplasmosis. Genotype I was predominant in ocular toxoplasmosis in northwest Iran. A larger comparative study should be conducted to provide a broader view of the molecular epidemiology of T. gondii genotypes and its role in toxoplasmosis.

Patient and treatment pathways for toxoplasmosis in the United States: data analysis of the Vizient Health Systems Data from 2011 to 2017

ABSTRACTToxoplasmosis causes substantial morbidity and mortality in the United States (US). Clinical manifestations to toxoplasmosis vary and there is limited information on incidence or treatment patterns in the US. Treatment pathways for pyrimethamine-based regimens and trimethoprim-sulfamethoxazole (TMP-SMX) for toxoplasmosis hospitalizations were investigated using the Vizient Health Systems inpatient and outpatient data. Between January 1st, 2011 and December 31st, 2017, 10,273 hospital visits from 4,736 unique patients received a primary or secondary ICD-9/ICD-10 diagnosis for toxoplasmosis. The projected annual hospital visits with a diagnosis of toxoplasmosis was 68,821, corresponding to a total annual incidence of 9,832 comprising ocular toxoplasmosis of 2,169, toxoplasmic encephalitis of 1,399, unspecified toxoplasmosis of 4,368, congenital toxoplasmosis of 381, multisystemic toxoplasmosis of 69 and other toxoplasmosis of 1,446. Only 16.3% of the study population received treatment with pyrimethamine-based regimens or TMP-SMX. Pyrimethamine-based regimens were used significantly more often than TMP-SMX in toxoplasmic encephalitis (88.7% vs 79.6%, p = 0.01), other toxoplasmosis (85.0% vs 79.2%, p = 0.04), and unspecified toxoplasmosis (87.6% vs 77.9%, p = 0.03) in hospitals with 300 beds or more. A significantly higher percentage of visits with TMP-SMX as first-line treatment switched to pyrimethamine-based regimens compared to visits initiated on pyrimethamine-based treatments (26.7% vs 4.1%, p < .001). Ocular toxoplasmosis patients receiving pyrimethamine-based therapy were more likely to be discharged home compared to TMP-SMC at rates of 72.4% and 55.2%, respectively. Our analysis of commercial insurance records suggest toxoplasmosis is undertreated. Overall, pyrimethamine-based regimens are favored over TMP-SMX, have higher rates of discharge home, and have lower switch rates.

Regional Differences in the Clinical Manifestation of Ocular Toxoplasmosis Between the Center and Northeast of Argentina

ABSTRACTPurpose: To compare the clinical characteristics of patients with active episodes of ocular toxoplasmosis from three provinces, Misiones, Santa Fe, and Buenos Aires, Argentina.Methods: Patients with a diagnosis of ocular toxoplasmosis from three databases of four tertiary referral uveitis centers were reviewed. Collected data included presentation of the retinochoroiditis, location of the active lesions, associated inflammatory ocular signs and complications.Results: Three hundred thirty-four patients were included in this study. Bilateral involvement of the ocular disease occurred in 26 patients in Misiones (35.14%), 21 patients (12.8%) in Santa Fe, and 9 patients in Buenos Aires (9.4%) (p < 0.001). Extensive retinitis was observed in 49 patients (66.2%) in Misiones, 39 patients (23.8%) in Santa Fe, and 12 patients (12.5%) in Buenos Aires (p < 0.001).Conclusion: The results indicate that there are differences in the clinical characteristics of ocular toxoplasmosis in patients from Misiones, Santa Fe, and Buenos Aires.

Correction to: Assessment of ocular toxoplasmosis patients reported at a tertiary center in the northeast of Iran.

Unfortunately, in the original publication of the article, given name and family name of the first and fourth author names were mentioned incorrectly. The exact given name and family name of those author names have been provided in the erratum.

Serologic Tests of IgG and IgM Antibodies and IgG Avidity for Diagnosis of Ocular Toxoplasmosis.

This prospective study was aimed to detect acute and chronic ocular toxoplasmosis by comparison of anti-Toxoplasma gondii IgM and IgG antibody levels and IgG avidity test. One hundred and seventeen patients with ocular toxoplasmosis (OT) who referred to the Farabi Eye Hospital, Tehran, Iran were included in this study. Of the patients, 77 cases were positive for anti-T. gondii IgG, and 8 cases were positive for anti-T. gondii IgM. IgG avidity test revealed 11, 4, and 102 cases were low, intermediate, and high, respectively, and 6.8% and 9.4% of cases were positive for IgM and IgG avidity tests, respectively (P=0.632). Agreement (Kappa value) between paired tests IgG-IgM, IgG-IgG avidity, and IgM-IgG avidity was 0.080, 0.099, and 0.721, respectively (P<0.05). This study showed that conventional serologic tests (IgM and IgG levels) and IgG avidity correlate well each other and can be used to differentiate recent infections from old OT. It seems that reactivated old infections rather than recently acquired infections are majority of Iranian OT patients.

Genetic Polymorphisms in Cytokine Genes in Colombian Patients with Ocular Toxoplasmosis.

Toxoplasmosis is caused by infection with the protozoan parasite Toxoplasma gondii, which has the capacity to infect all warm-blooded animals worldwide. Toxoplasmosis is a major cause of visual defects in the Colombian population; however, the association between genetic polymorphisms in cytokine genes and susceptibility to ocular toxoplasmosis has not been studied in this population. This work evaluates the associations between polymorphisms in genes coding for the cytokines tumor necrosis factor alpha (TNF-α) (rs1799964, rs1800629, rs1799724, rs1800630, and rs361525), interleukin 1β (IL-1β) (rs16944, rs1143634, and rs1143627), IL-1α (rs1800587), gamma interferon (IFN-γ) (rs2430561), and IL-10 (rs1800896 and rs1800871) and the presence of ocular toxoplasmosis (OT) in a sample of a Colombian population (61 patients with OT and 116 healthy controls). Genotyping was performed with the "dideoxynucleotide (ddNTP) primer extension" technique. Functional-effect predictions of single nucleotide polymorphisms (SNPs) were done by using FuncPred. A polymorphism in the IL-10 gene promoter (-1082G/A) was significantly more prevalent in OT patients than in controls (P = 1.93e-08; odds ratio [OR] = 5.27e+03; 95% confidence interval [CI] = 3.18 to 8.739; Bonferroni correction [BONF] = 3.48e-07). In contrast, haplotype "AG" of the IL-10 gene promoter polymorphisms (rs1800896 and rs1800871) was present at a lower frequency in OT patients (P = 7e-04; OR = 0.10; 95% CI = 0.03 to 0.35). The +874A/T polymorphism of IFN-γ was associated with OT (P = 3.37e-05; OR = 4.2; 95% CI = 2.478 to 7.12; BONF = 6.07e-04). Haplotype "GAG" of the IL-1β gene promoter polymorphisms (rs1143634, rs1143627, and rs16944) appeared to be significantly associated with OT (P = 0.0494). The IL-10, IFN-γ, and IL-1β polymorphisms influence the development of OT in the Colombian population.

Assessment of ocular toxoplasmosis patients reported at a tertiary center in the northeast of Iran.

Ocular toxoplasmosis, which is caused by the single-cell parasite Toxoplasma gondii, is currently the most significant cause of posterior uveitis in the world. No previous studies have described the prevalence and clinical features of ocular toxoplasmosis in the northeast of Iran. The purpose of the current study was to address this gap. In this retrospective study, the medical records of 488 uveitis patients who presented to the Khatam-al-Anbia Eye Hospital of Mashhad University of Medical Sciences, a tertiary ophthalmology center in the northeast of Iran, between January 2013 and December 2015 were evaluated. The clinical features and risk factors of 99 (20%) consecutive patients with ocular toxoplasmosis were extracted. Ninety-nine including 53 (53.5%) female and 46 (46.5%) male patients with ocular toxoplasmosis were included in the analysis. Reduced vision (77%) and floaters (15.2%) were the most common presenting symptoms. The age category that was most affected by ocular toxoplasmosis was 20-40years (range: 11-65years) with a mean age of 27.2. All patients had retinochoroiditis, but just two had anterior uveitis. All of the extracted patients, with the exception of three patients, had unilateral involvement. None of the patients had any other medical disorders with the exception of one woman, who had diabetes. Only four recurring ocular toxoplasmosis patients were referred to the education hospital during the study. Serology data were available for just 32 patients, of which 31 (96.8%) were IgG positive, and 1 (3.2%) was IgM positive. Toxoplasma gondii was responsible for 20% of the patients of uveitis that presented to the largest ophthalmology center in the northeast of Iran. There is a high incidence of patients of ocular toxoplasmosis in the northeast of Iran, and it is a significant cause of uveitis and visual impairment in this area.

Seroprevalence and Manifestations of Ocular Toxoplasmosis in Patients with Schizophrenia

ABSTRACTPurpose: Recent studies have linked infectious agents such as Toxoplasma gondii to schizophrenia. We investigated the seroprevalence of T. gondii and conducted ophthalmologic examinations in schizophrenia patients and controls to identify lesions suggestive of ocular toxoplasmosis.Methods: During 2015 and 2016, 34 schizophrenia patients and 85 healthy controls underwent ophthalmologic examination and anti-T. gondii IgG and IgM antibody measurements by chemiluminescence.Results: Schizophrenia patients had a higher prevalence of anti-T. gondii IgG positivity than controls (91.18% [95% confidence interval (CI), 77.04%–96.95%] vs. 70.59% [95% CI, 60.18%–79.21%]; p = 0.017). Anti-T. gondii IgM antibodies (acute form) were not detected in any patient. One (3%) schizophrenic patient and two (2.4%) control patients presented fundoscopic scarring.Conclusion: The seropositivity rate was significantly higher among schizophrenia patients than among controls (p = 0.017). There was no association between the presence of fundoscopic scarring and schizophrenia (p = 1.000).

Ocular Toxoplasmosis: Therapy-Related Adverse Drug Reactions and Their Management.

Background There are different treatment options for ocular toxoplasmosis (OT). "Classic" therapy consists of pyrimethamine, sulfadiazine and folinic acid combined with systemic steroids and is still widely used. However, potentially severe side effects of this therapy have been reported. The aim of this retrospective study was to evaluate the incidence and types of adverse drug reactions in patients treated for OT. Clinical management of each adverse drug reaction was assessed. Patients and Methods In this retrospective analysis, we reviewed data of patients with OT, who were consecutively examined between December 2011 and December 2015 at the Department of Ophthalmology, University Hospital Zurich. Results In total, 49 patients had at least one episode of active OT. In 54 (83.0 %) of 65 treated episodes, the classic regimen was used. Of the 37 patients who received classic treatment, 9 (24.3 %) developed at least one adverse drug reaction which led to drug discontinuation, including elevated creatinine (5.4 %), elevated liver enzymes (5.4 %), vomiting (5.4 %), rash (5.4 %) and facial swelling (2.7 %). In 5 patients, treatment was switched to another drug, while in the other 4 patients, therapy was stopped. In these 9 patients, inflammation was well controlled 8 weeks after onset of therapy. No patient suffered from severe side effects, such as potentially life-threatening allergic reactions or pancytopenia. Conclusions In OT patients who were treated with classic therapy, adverse drug reactions are common. Therefore, clinical and laboratory monitoring is mandatory. Adverse drug reactions may require interdisciplinary management.

Th1 and Th2 immune response to P30 and ROP18 peptides in human toxoplasmosis.

We determined the specific lymphocyte proliferative response and cytokine profile production regarding Toxoplasma P30 (2017 from virulent and non-virulent strain) and ROP18 protein-derived peptides (from clonal lineages I, II and III) in 19 patients having ocular toxoplasmosis, five suffering chronic asymptomatic infection, nine with congenital toxoplasmosis and eight Toxoplasma negative people. A Beckman Coulter FC500 flow cytometer was used for determining antigen-specific T cells (CD3+ CD4+ or CD3+ CD8+ cells) in peripheral blood culture. IFN γ and IL10 levels were determined in culture supernatants. Specific CD4+ and CD8+ T cell response to total antigen and P30- and ROP18-derived peptides was observed in infected people. Ocular toxoplasmosis patients had a preferential Th2 response after antigenic stimulation. Non-virulent peptide 2017 was able to shift response toward Th1 in congenitally infected children and virulent peptide 2017 induced a Th2 response in chronically infected, asymptomatic people. An immune response in human toxoplasmosis after ex vivo antigenic stimulation was Th1- or Th2-skewed, depending on a patient's clinical condition. Colombian ocular toxoplasmosis patients' immune response was Th2-skewed, regardless of the nature of antigen stimulus.

Cerebral and ocular toxoplasmosis related with IFN-γ, TNF-α, and IL-10 levels.

This study analyzed the synthesis of Interferon gamma (IFN-γ), Tumor Necrosis Factor alpha (TNF-α), and Interleukin 10 (IL-10) in chronically infected patients which developed the symptomatic disease as cerebral or ocular toxoplasmosis. Blood from 61 individuals were divided into four groups: Cerebral toxoplasmosis/AIDS patients (CT/AIDS group) (n = 15), ocular toxoplasmosis patients (OT group) (n = 23), chronic toxoplasmosis individuals (CHR group) (n = 13) and healthy individuals (HI group) (n = 10). OT, CHR, and HI groups were human immunodeficiency virus (HIV) seronegative. The diagnosis was made by laboratorial (PCR and ELISA) and clinical subjects. For cytokine determination, peripheral blood mononuclear cells (PBMC) of each patient were isolated and stimulated in vitro with T. gondii antigen. IFN-γ, TNF-α, and IL-10 activities were determined by ELISA. Patients from CT/AIDS and OT groups had low levels of IFN-γ when were compared with those from CHR group. These data suggest the low resistance to develop ocular lesions by the low ability to produce IFN-γ against the parasite. The same patients, which developed ocular or cerebral toxoplasmosis had higher TNF-α levels than CHR individuals. High TNF-α synthesis contribute to the inflammatory response and damage of the choroid and retina in OT patients and in AIDS patients caused a high inflammatory response as the TNF-α synthesis is not affected since monocytes are the major source this cytokine in response to soluble T. gondii antigens. IL-10 levels were almost similar in CT/AIDS and OT patients but low when compared with CHR individuals. The deviation to Th2 immune response including the production of anti-inflammatory cytokines, such as IL-10 may promote the parasite's survival causing the tissue immune destruction. IL-10 production in T. gondii-infected brains may support the persistence of parasites as down-regulating the intracerebral immune response. All these indicate that OT and CT/AIDS patients produced low levels of IL-10 (Th2 response) and IFN-γ (Th1 response). They produced high TNF-α suggesting a high inflammatory response triggered by the parasite.

Severe South American ocular toxoplasmosis is associated with decreased Ifn-γ/Il-17a and increased Il-6/Il-13 intraocular levels.

In a cross sectional study, 19 French and 23 Colombian cases of confirmed active ocular toxoplasmosis (OT) were evaluated. The objective was to compare clinical, parasitological and immunological responses and relate them to the infecting strains. A complete ocular examination was performed in each patient. The infecting strain was characterized by genotyping when intraocular Toxoplasma DNA was detectable, as well as by peptide-specific serotyping for each patient. To characterize the immune response, we assessed Toxoplasma protein recognition patterns by intraocular antibodies and the intraocular profile of cytokines, chemokines and growth factors. Significant differences were found for size of active lesions, unilateral macular involvement, unilateral visual impairment, vitreous inflammation, synechiae, and vasculitis, with higher values observed throughout for Colombian patients. Multilocus PCR-DNA sequence genotyping was only successful in three Colombian patients revealing one type I and two atypical strains. The Colombian OT patients possessed heterogeneous atypical serotypes whereas the French were uniformly reactive to type II strain peptides. The protein patterns recognized by intraocular antibodies and the cytokine patterns were strikingly different between the two populations. Intraocular IFN-γ and IL-17 expression was lower, while higher levels of IL-13 and IL-6 were detected in aqueous humor of Colombian patients. Our results are consistent with the hypothesis that South American strains may cause more severe OT due to an inhibition of the protective effect of IFN-γ.