Evaluation of Toxoplasma gondii IgG avidity assays through a comparison of IgM serostatus.

Primary Toxoplasma gondii (T. gondii) infection during pregnancy could result in congenital disease with severe clinical complications. IgM antibodies are one of the indices of primary infection. The IgG avidity index (AI) is also known to remain low for at least 3 months after primary infection. Here, we evaluated and compared the performance of T. gondii IgG avidity assays as confirmed by T. gondii IgM serostatus and number of days post-exposure. Four assays preferentially used in Japan were employed to measure the T. gondii IgG AI. Results for the T. gondii IgG AI showed good concordance, particularly in cases with a low IgG AI. This study confirms that the combination of T. gondii IgM and IgG AI tests is a reliable and suitable method for identifying T. gondii primary infections. Our study proposes the necessity of measuring the T. gondii IgG AI as an additional indicator of T. gondii primary infection.

Protection of Fatty Liver by the Intake of Fermented Soybean Paste, Miso, and Its Pre-Fermented Mixture.

Soybeans and fermented soy-derived foodstuffs contain many functional components and demonstrate various beneficial effects. In this report, we demonstrate the anti-fatty liver effect of miso, a traditional fermented product made from soybeans and rice molded in Aspergillus oryzae and forming a common part of the Japanese diet. After acclimation for 2 weeks, male and female C57BL/6J mice were fed with a normal diet (ND), a high-fat diet (HFD), a HFD containing 5% miso (HFD+M), or a HFD containing 5% pre-fermented miso (HFD+PFM) for 20 weeks. Although mice in the HFD group developed typical fatty liver, the consumption of miso or PFM significantly ameliorated the progression of fatty liver in female mice. The liver weight and the average nonalcoholic fatty liver disease activity score (NAS) were significantly reduced in the HFD+M and HFD+PFM groups. In addition, leptin and resistin levels in the serum were decreased in the HFD+M and HFD+PFM groups. The progression of fatty liver was also prevented by the consumption of miso or PFM in male mice, although there were no decreases in NAS. Therefore, miso appears to be a potential food to prevent lifestyle-related diseases such as metabolic syndrome.

The Cytotoxic Effects of Geranylgeranylacetone Are Attenuated in the High-Glucose Condition.

Geranylgeranylacetone (GGA) has been used as an antiulcer drug and also is known as inducer of heat shock protein 70 that has cytoprotective effects especially in hyperglycemic condition. In contrast, cytotoxicity of GGA has also been reported. Some studies have reported that GGA suppresses cell growth and induces apoptosis in cell models of human leukemia, ovarian carcinoma, and colon cancer in vitro. Therefore, the aim of this study was to determine whether GGA can have a cytotoxic effect on a human cervical cancer cell line (HeLa), human colorectal adenocarcinoma cells (Caco-2), and human embryonic kidney cells 293 (HEK) in normal-glucose and high-glucose environments (NG and HG, respectively). The results showed that 100 µM GGA inhibited proliferation of HeLa cells only in NG environment despite inhibiting proliferation of Caco-2 and HEK cells regardless of glucose concentration. Cell viability assay revealed that GGA decreased viability of HeLa, Caco-2, and HEK cells only in NG environment. Flow cytometric analyses revealed that the type of cell death was a combination of necrosis and apoptosis. Our study revealed that difference in cytotoxicity of GGA is influenced by glucose condition. The cytotoxic effects of GGA are attenuated in the HG condition. Since both cytotoxic and cytoprotective effects are reported about GGA, further research is needed about the mechanism of the cytotoxic effects.

Evaluation of the indirect and IgM-capture anti-human cytomegalovirus IgM ELISA methods as confirmed by cytomegalovirus IgG avidity.

Primary cytomegalovirus (CMV) infection during pregnancy often results in congenital CMV infection with severe clinical complications. IgM antibodies are one of the indices of primary infection. The IgG avidity index (AI) is also known to remain low for 3 months after primary infection. Here, we evaluated and compared the performance of CMV IgM and IgG avidity assays. Because sensitivity and specificity reportedly differ between CMV IgM kits, CMV IgM detection was compared between the two commercially available ELISA kits that are most commonly used in Japan. Sera for CMV IgM were first screened using a traditional indirect ELISA kit. Selected samples were then tested for CMV IgM and CMV AI using a CMV IgM-capture ELISA kit and a CMV IgG avidity assay, respectively. The rate of concordance between the IgM kits was 89% (42/47), indicating the absence of any significant difference. Most of the CMV IgM-positive plasma samples showed high CMV IgG AI; however, 18 commercially available plasma samples with low CMV IgG AI were all CMV IgM-positive. One plausible explanation for this discrepancy is that the duration of low IgG AI is shorter than that of IgM positivity. Alternatively, CMV IgM tests may generate pseudo-positive readouts in cases of congenital infection. Nevertheless, our study confirms that CMV IgG AI can be a reliable indicator of CMV primary infection.

Detection of engraftment of donor-derived antibody producing cells in a lung transplant recipient by anti-cytomegalovirus IgG avidity test.

Transplant recipients become immunocompromised through the use of immunosuppressive therapy to prevent allograft rejection. These recipients readily experience human cytomegalovirus (CMV) infection or reactivation. Therefore, CMV represents a life-threatening pathogen in transplant recipients. To demonstrate the serostatus and course of IgG maturation against CMV in transplant patients, we measured the transition of anti-CMV IgG and its affinity (avidity index; AI) as criteria for antibody maturation. Among 31 lung transplant recipients, 26 were infected with CMV before transplantation and maintained anti-CMV IgG and high AI values throughout the study period. Four of the 31 experienced primary infection with CMV through the allograft, with two of the 4 recipients presented high AI values even after 6 month post-transplantation. A significant portion of donor-derived plasma cells were detectable in one recipient. These results suggested that the plasma cells from donors are carried in through the transplanted lung and lymph nodes and produce matured high-avidity IgG from the early stage of transplantation.

A Double-Blind Controlled Study to Evaluate the Effects of Yogurt Enriched with Lactococcus lactis 11/19-B1 and Bifidobacterium lactis on Serum Low-Density Lipoprotein Level and Antigen-Specific Interferon-γ Releasing Ability.

In order to clarify the effects of the Lactococcus lactis (L. lactis) 11/19-B1 strain, a double-blind controlled study of yogurt fermented with the strain was carried out. For the study, two kinds of yogurt, the control and test yogurt, were prepared; the control yogurt was fermented with Streptococcus thermophiles, Lactobacillus delbrueckii subspecies bulgaricus, and Lactobacillus acidophilus, and the test yogurt was enriched with L. lactis 11/19-B1 and Bifidobacterium lactis (B. lactis) BB-12 strains. Seventy-six volunteers who had not received treatment with pharmaceuticals were randomly divided into two groups with each group ingesting 80 g of either the test or control yogurt every day for 8 weeks. Before and after yogurt intake, fasting blood was taken and blood sugar, blood lipids, and anti-cytomegalovirus cellular immunity were estimated. In the test yogurt group, low-density lipoprotein (LDL) was significantly decreased (159.1 ± 25.7 to 149.3 ± 24.4; p = 0.02), but this effect was not observed in the control yogurt group. When the test yogurt group was divided into two groups based on LDL levels of over or under 120 mg/dL, this effect was only observed in the high LDL group. No LDL-lowering effect of B. lactis BB-12 strain was previously reported; therefore, the hypocholesterolemic effects observed in this study are thought to be caused by the L. lactis 11/19-B1 strain alone or its combination with the B. lactis BB-12 strain.

Modification of the HCMV-specific IFN-γ release test (QuantiFERON-CMV) and a novel proposal for its application.

Human cytomegalovirus (HCMV) is universally distributed among humans without any adverse effects; however, it induces severe diseases in immunocompromised patients such as organ transplant recipients and AIDS patients. To manage these immunocompromised patients, an easy clinical examination for the monitoring of disease risk is required. In this study, we modified the interferon-γ (IFN-γ) release test (QuantiFERON®-CMV) using HCMV immediate early-1 (IE-1) or pp65 whole proteins, or UV-inactivated HCMV particles as an antigen. The response of heparinized peripheral blood from healthy volunteers to the pp65 protein showed an obvious dose-dependent sigmoid curve, although no correlation was observed between results of this assay and an ELISPOT assay. The addition of pp65 to the blood samples at a final concentration of 1×103 to 1×105 pg/ml was found to be optimum. Using this assay, we observed a significant enhancement in cellular immunity in volunteers after the daily ingestion of yogurt for 8 weeks, which suggested a novel application of the assay in addition to monitoring HCMV infection risk. IFN-γ secretion from peripheral blood cells on HCMV-antigen stimulation differed significantly between individuals; therefore, the assay could not be normalized. Nevertheless, it was found to be particularly useful for observing fluctuations in cellular immune activity on an individual level.