Chemiluminescent microparticle immunoassay cmia

Thyroid hormone measurements were performed using a Chemiluminescent Microparticle Immunoassay (CMIA), an immunoassay analyzer (ARCHITECT i1000SR, Abbott Lab., Abbott Park, IL, USA), and specific, dedicated diagnostic kits (ARCHITECT Free T3, FT4 and TSH assay, Abbott Lab., Abbott Park, IL, USA), as previously described [16 (link)]. The conventional reference intervals for FT3, FT4, and TSH were 1.71–3.71 pg/mL, 0.7–1.48 ng/dL and 0.35–4.0 µIU/mL, respectively.

We used two structured questionnaires for data collection from the mothers and infants. The questionnaire for mothers included the demographic data about the family, mother, delivery, diet, daily sun exposure and maternal intake of calcium/ VD₃ containing vitamins during and after pregnancy. The questionnaire for the infants included the demographic parameters and characteristics including feeding habits that can affect the VD₃ status. Three milliliters of venous blood were obtained by the standard procedure from both mother & baby in special vials. All the samples were stocked at -2 to -8°C till the analysis were made. VD₃ estimation was done by FDA approved Abbott Laboratories’ chemiluminescent microparticle immunoassay (CMIA – Abbott Park, IL). We also obtained levels of Ca⁺², PO₄^-3, alkaline phosphatase, parathormone and albumin. Taking reference the current recommendations10 the cut-off points for VD₃ deficiency and VD₃ insufficiency used were <30 nmol/L and <50 nmol/L, respectively. The optimal level of VD₃ for infants was taken as >80 nmol/L and >50 nmol/L for nursing mothers.

Examination of IgM anti Spike protein of SARS-CoV2 and IgG against Spike RBD of SARS-CoV-2 will be performed using Chemiluminescent Microparticle Immunoassay (CMIA) from Abbot (Cat. 6R87 for IgM and 6S60 for IgG). Two types of immunoassays are used in this study. Both are automated, two-step immunoassays. The SARS-CoV-2 IgM assay is used for the qualitative detection of IgM antibodies SARS-CoV2, and the SARS-CoV-2 IgG II Quant assay is used for the qualitative and quantitative determination of IgG antibodies against SARS-CoV-2. Serum or plasma (separated by dipotassium EDTA or tripotassium EDTA or lithium heparin or sodium heparin or sodium citrate) can be used in this assay. Both of the assays have an identical principle in the procedure. The sample, SARS-CoV2 antigen coated paramagnetic particles, and assay diluent are mixed and incubated. The IgM and IgG antibodies against SARS-CoV2 present in the sample will bind to the SARS-CoV2 antigen-coated microparticle. The detection of IgM and IgG are processed separately. After the washing step, anti-human IgM or IgG acridinium-labeled conjugate is added to the mixture and incubated. Following a wash cycle, Pre-Trigger and Trigger Solutions are added. The resulting chemiluminescent reaction is measured as a relative light unit (RLU) [35 (link), 36 (link)].

Serum ALT was measured using automated biochemical techniques (Hitachi 7600, Tokyo, Japan) (upper limit of normal: 35 IU/L). The serum HBeAg level was determined using the Chemiluminescent Microparticle Immunoassay (CMIA) kit for the Architect-i2000 system (Abbott Laboratories, Chicago, IL, USA), with a positive result recorded as S/CO ≥ 1.0. The serum HBV DNA load was also determined by ABI 7300 fluorescent quantitative PCR (Applied Biosystems Corporation, Foster City, CA, USA), with a detection limit of 300 viral genome copies/mL.

Venous blood samples were collected from each patient into a tube with a clot activator (S-Monovette, SARSTEDT, Numbrecht, Germany), centrifuged to obtain serum samples, and stored at −80 °C until assayed. The tested chemokines were measured with the use of a Luminex 200 analyzer (Thermo Fisher Scientific, Waltham, MA, USA) (multiplexing, multiparametric, fluorescence laser reading system on microspheres for the simultaneous determination of multiple parameters) and Luminex Human Discovery assay plates, provided by R&D systems, Abingdon, UK. According to the manufacturer’s protocols, duplicate samples were assessed for each standard, control, and sample. The serum levels of classical tumor markers were measured with chemiluminescent microparticle immunoassay (CMIA) (Abbott, Chicago, IL, USA); and, for the analysis of the CRP concentration, the immunoturbidymetric method (Abbott, Chicago, IL, USA) was used according to the manufacturer’s protocols.