Evaluation of the performance of an immunoturbidimetric HbA1c reagent applied to the Siemens ADVIA 2400 automatic analyzer.

OBJECTIVES: A new immunochemical reagent based on latex particles and antibodies against HbA1c (Axis-Shield), using Siemens ADVIA 2400 Instrument was evaluated. DESIGN AND METHODS: Intra-assay and total imprecision, interferences studies (bilirubin ~850 µmol/L, triglycerides ~16.9 mmol/L, total protein ~140 g/L, sodium cyanate ~50 mg/dL, ascorbic acid ~50 mg/dL, urea ~24.99 mmol/L, glucose ~105.46 mmol/L, rheumatoid factor ~600 U/mL), method comparison vs Capillary Electrophoresis (Sebia), Lot to Lot reproducibility, linearity and carry over were conducted on ADVIA 2400 according to CLSI protocols. Additionally, 40 samples were measured by the two methods and also by a NGSP reference lab. RESULTS: CVs % obtained by intra-assay imprecision, on 3 human HbA1c specimens at different concentrations (48, 48-64 and >64 mmol/mol) in 20 replicates, were <4%. CVs % by total imprecision, performed over 20 days with 4 calibrations on 3 human HbA1c samples (48, 48-64 and >64 mmol/mol), resulted <4%. Interferences were studied on two human samples (42-53 and>64 mmol/mol) without obtaining significant biases (<10%). Methods comparison vs Capillary Electrophoresis, performed on 120 samples ranging 23-137 mmol/mol, obtaining r = 0.974 as regression coefficient and a mean bias at decision level (48 mmol/mol) <3%. The results obtained with the NGSP samples have allowed the certification of the new reagent. CONCLUSIONS: The ASD reagent met the needs of clinical laboratories, fulfilling both NGSP and IFCC requirements and it is robust to endogenous interferences.

Antileishmanial activity of a mixture of Tridax procumbens and Allium sativum in mice.

We tested a mixture of Tridax procumbens, known for its direct action against Leishmania mexicana, and Allium sativum, known for its immunomodulatory effect, as an alternative to treat cutaneous leishmaniasis. Acute oral toxicity was tested with the Up-and-Down Procedure (UDP) using a group of healthy mice administered with either T. procumbens or A. sativum extracts and compared with a control group. Liver injury and other parameters of toxicity were determined in mice at day 14. The in vivo assay was performed with mice infected with L. mexicana promastigotes and treated with either a mixture of T. procumbens and A. sativum or each extract separately. The thickness of the mice's footpads was measured weekly. After the 12-week period of infection, blood samples were obtained by cardiac puncture to determine the total IgG, IgG1 and IgG2a immunoglobulins by a noncommercial indirect ELISA. We showed that the mixture of T. procumbens and A. sativum extracts was better at controlling L. mexicana infection while not being toxic when tested in the acute oral toxicity assay in mice. An increase in the ratio of IgG2a/IgG1 indicated a tendency to raise a Th1-type immune response in mice treated with the mixture. The mixture of T. procumbens and A. sativum extracts is a promising natural treatment for cutaneous leishmaniasis and its healing effects make it a good candidate for a possible new phytomedicine.