Assessment of tissue levels of miR-146a and proinflammatory cytokines in experimental cerebral toxoplasmosis following atovaquone and clindamycin treatment: An in vivo study.

BACKGROUND: Despite recent advances for treating cerebral toxoplasmosis (CT), monitoring the parasite burden and treatment response is still challenging. miRNAs are small non-coding RNAs with regulatory functions that can be used in diagnosis and treatment monitoring. We investigated the changes in miR-146a, BAG-1 gene, IL-6, and IL-10 tissue levels in the brain of BALB/c mice with chronic CT caused by the PRU strain of T. gondii following anti-parasitic and antibiotic treatment. METHOD: Fifty-three 6-to 8-week-old BALB/c mice were infected using intraperitoneal inoculation of cerebral cysts of T. gondii PRU strain and then divided into five groups as follows: group 1 included mice treated with 100 mg/kg/d Atovaquone (AT), group 2 included mice treated with 400 mg/kg/d clindamycin (CL), group 3 included mice treated with combination therapy (AT + CL), group 4 included infected untreated mice as a positive control (PC), and; group 5 included uninfected untreated mice as negative control (NC). After the completion of the treatment course, tissue level of mir-146a, miR-155, BAG-1 gene, IL-6, and IL-10 was investigated with real-time polymerase chain reaction. The IL-6/IL-10 ratio was calculated as an indicator of immune response. Moreover, brain cyst numbers were counted on autopsy samples. RESULTS: miR-146a, IL-6, IL-10, and BAG-1 genes were expressed in PC, but not in the NC group; miR-146a, IL-6, IL-10, and BAG-1 gene expression were significantly lower in AT, CL, and AT + CL compared with PC. MiR-146a and BAG-1 levels in AT and CL were not different statistically, however, they both had lower levels compared to AT + CL (P < 0.01). There was no difference in the expression of IL-6 and IL-10 between treatment groups. BAG-1 expression was significantly lower in AT, than in CL and AT + CL (P < 0.0089 and < 0.002, respectively). The PC group showed a higher ratio of IL-6/IL-10, although this increase was not statistically significant. It is noteworthy that the treatment with AT reduced this ratio; in the inter-group comparison, this ratio showed a decrease in the AT and AT + CL compared to the PC. The number of brain tissue cysts was significantly lower in AT, CL, and AT + CL, than in PC (p < 0.0001). AT had significantly lower brain cysts than CL and AT + CL (P < 0.0001). CONCLUSION: It seems that the factors studied in the current research (microRNA and cytokines) are a suitable index for evaluating the response to antiparasitic and antibiotic treatment. However, more studies should be conducted in the future to confirm our findings.

The association of latent toxoplasmosis and level of serum testosterone in humans.

OBJECTIVES: Latent toxoplasmosis modifies various hormones and behaviors in infected hosts and possibly involves in etiology of different neurologic and psychiatric disorders. The aim of the current study was to assess possible associations between latent toxoplasmosis and testosterone concentration in Toxoplasma infected and free subjects. Briefly, 18-49 year-old participated in the study. After collected blood samples, sera were analyzed for the detection of anti-Toxoplasma IgG antibody. Totally, 76 positive sera were selected as study group (38 from men and 38 from women) and a same number of negative sera as control group. RESULTS: Comparison of testosterone concentrations and control groups showed that testosterone concentration in study group was higher than that in control group with statistically significant difference (P = 0.024 and P = 0.043 for men and women, respectively). Significant differences were found in testosterone concentrations and anti-Toxoplasma IgG antibody levels in study and control groups (P < 0.05). Toxoplasmosis can affect the mean concentration of serum testosterone in human. Alteration of testosterone during latent toxoplasmosis can result in alterations in behavioral, physiologic and immunological parameters in long time.

Detection of toxoplasma-specific immunoglobulin G in human sera: performance comparison of in house Dot-ELISA with ECLIA and ELISA.

In the current study, performance of electrochemiluminescence immunoassay (ECLIA) in detection of anti-toxoplasma IgG in human sera was compared with that of enzyme-linked immunosorbent assay (ELISA). Furthermore, performance of an in house Dot-ELISA in detection of anti-toxoplasma IgG was compared with that of ECLIA and ELISA. In total, 219 human sera were tested to detect anti-toxoplasma IgG using Dynex DS2® and Roche Cobas® e411 Automated Analyzers. Discordant results rechecked using immunofluorescence assay (IFA). Then, sera were used in an in house Dot-ELISA to assess toxoplasma-specific IgG. Of the 219 samples, two samples were found undetermined using ECLIA but reactive using ELISA. Using IFA, the two sera were reported unreactive. Furthermore, two samples were found reactive using ECLIA and unreactive using ELISA. These samples were reported reactive using IFA. The overall agreement for the two former methods was 98% (rZ0.98.1; P < 0.001). The intrinsic parameters calculated for in house Dot-ELISA included sensitivity of 79.5, specificity of 78.2, and accuracy of 78.9%, compared to ECLIA and ELISA. Positive and negative predictive values included 82.9 and 74.2%, respectively. A 100% sensitivity was found in in house Dot-ELISA for highly reactive sera in ECLIA and ELISA. ECLIA is appropriate for the first-line serological screening tests and can replace ELISA due to high speed, sensitivity, and specificity, particularly in large laboratories. Dot-ELISA is a rapid, sensitive, specific, cost-effective, user-friendly, and field-portable technique and hence can be used for screening toxoplasmosis, especially in rural fields or less equipped laboratories.