External quality assessment scheme for HbA1c assays in Thailand: A 5-year experience.

Background: Thailand National External Quality Assessment Scheme (NEQAS) for HbA1c was established to evaluate the quality of HbA1c assays in Thailand in 2016. Methods: HbA1c results from participating laboratories were compared to the target value assigned by the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) reference system. Results: The pass rates of participating laboratories during 2016-2020 were72-88%. The mean bias ranged between -0.19 and 0.20% of HbA1c. SD ranged from 0.30 to 1.08% of HbA1c. The overall coefficients of variation ranged from 4.46-15.66%. Conclusions: Performance evaluation using IFCC assigned values indicated that different assay methods had an effect on HbA1c results. Participation in external quality assessment programs for HbA1c analysis is essential for improving laboratory quality and benefiting patient management.

Immune activation and viral replication after vaccination with an influenza A H1N1 2009 vaccine in HIV-infected children receiving antiretroviral therapy.

Immunization with a pandemic influenza A H1N1 2009 was recommended for HIV-infected patients. However, there is limited information concerning the impact of immunization with this vaccine on immune activation and HIV viral replication. In this study, 45 HIV-infected children and adolescents receiving antiretroviral therapy were immunized with a 2-dose series of nonadjuvated monovalent influenza A H1N1 2009 vaccine upon enrollment and approximately 1 month later. Immunogenicity was determined by haemagglutination inhibition assay. The level of immune activation was determined by identification of CD38 and HLA-DR on CD8+ T cells. Patients were divided into 2 groups which include patients who had an undetectable HIV viral load (HIV detectable group) and patients who show virological failure (HIV nondetectable group). The results showed seroconversion rate of 55.2% in HIV nondetectable group, whereas 31.3% was found in HIV detectable group. Both groups of patients showed no major increase in immune activation after immunization. Interestingly, a decrease in the frequency of CD8+ T cells that coexpressed CD38 and HLA-DR was observed after immunization in both groups of patients. We suggested that immunization with influenza A H1N1 2009 vaccine can induce immune response to the pandemic virus without major impact on HIV viral replication and immune activation.

Influence of cell isolation method on the optimization of CD4+ T cell expansion using anti-CD3/CD28 coated beads.

BACKGROUNDS: Activation of CD4+ T lymphocytes with anti-CD3/CD28 coated magnetic beads promotes intrinsic resistance to HIV as well as cell expansion. The propose of this study is to define the optimal cell isolation protocol for expansion of CD4+ T lymphocytes by using anti-CD3/CD28 coated bead stimulation with an ultimate goal of using these cells for adoptive immunotherapy. METHODS: CD4+ T cells were isolated from healthy donor blood samples using three different methods including immunorosette formation, negative selection and CD8 depletion using immunomagnetic beads. These cells were activated with anti-CD3/CD28 coated beads at a bead to cell ratio of 1:1 and cell expansion was carried for 3 weeks. Cell numbers, cell viability and phenotypic characterization were determined by trypan blue exclusion and flow cytometry. RESULTS: Purified CD4+ T lymphocytes which were isolated via immunorosette formation can be expanded up to 1000-fold within 3 weeks with high viability (90%and high purity of CD4+ T lymphocytes (>95%). However, cell expansion from purified CD4+ T lymphocytes which were isolated by negative selection and CD8-depletion provided approximately 300-fold expansion. CONCLUSIONS: The results demonstrate that purified CD4+ T lymphocytes from immunorosette formation provided the highest CD4+ T lymphocyte expansion when stimulated with anti-CD3/CD28 coated beads. This method can be used to obtain a large number of expanded CD4+ T cells for adoptive immunotherapy.