Immulite 2000

The files of 120 consecutive patients with ATD from a community endocrinology clinic were reviewed. These patients were diagnosed with either Hashimoto’s thyroiditis or Graves’ disease. Data collected included anti-thyroglobulin antibodies (Tg-Ab), anti-thyroid peroxidase antibodies (TPO-Ab), PC-Ab and tTG-Ab. For patients with positive PC-Ab and/or tTG-Ab, results of upper gastrointestinal (GI) endoscopy were recorded. Gastrin levels were collected in patients with positive PC-Ab.
Anti-thyroid peroxidase antibodies and Tg-Ab were measured using a solid phase, enzyme-labeled, chemiluminescent sequential immunometric assay (Immulite 2000, Siemens Healthcare Diagnostics Inc., UK). TPO-Ab and Tg-Ab levels were expressed in IU/ml. IgA tTG-Ab were measured by multiplex flow immunoassay (Bioplex 2200, Bio-Rad Laboratories, Inc.). Anti-tissue transglutaminase antibodies levels were measured in U/ml, and expressed by positivity. PC-Ab were measured by immunofluorescence antibody assay. Gastrin levels were measured by a chemiluminescent, enzyme-labeled immunometric assay (Immulite 2000, Siemens Healthcare Diagnostics Inc., UK). The normal reference range for serum gastrin is 13–115 pg/ml.

ACTH, DHEAS and androstenedione were measured using the Siemens Immulite 2000 immunoassay. The limit of quantification (LoQ) for ACTH, DHEAS and androstenedione were 5 ng/L, 0.4 µmol/L and 1.1 nmol/L, respectively.
Cortisol, fT4, TSH, testosterone and gonadotrophins were measured using Siemens ADVIA Centaur. The LoQ for cortisol, fT4 and TSH were 3 nmol/L, 1.3 pmol/L and 0.005 mIU/L, respectively.
Mitotane concentrations were obtained by LYSOSAFE Service, HRA Pharma, using a standardised HPLC method with an LoQ below 1 mg/L.
Thyroid-binding globulins in serum were measured in duplicate using an automated solid-phase competitive chemiluminescent enzyme immunoassay (Immulite 2000, Siemens, UK). Grossly lipaemic or haemolysed samples were removed. The LoQ of the assay was 29.6 nmol/L, and there was no reported cross-reactivity with similar analytes. Intra-assay and inter-assay coefficient of variation (CV%) at 68.8 nmol/L were 16.2% and 21.2%, and at 1330.1 nmol/L were 6.1% and 10.7%, respectively.
A manual ELISA method was used to quantify cortisol binding globulin in serum, which was a non-competitive sandwich immunoassay (BioVender, Brno, Czech Republic). There was no reported cross-reactivity of the assay. Intra-assay CV at 43.2 µg/mL and at 73.28 µg/mL were 1.2% and 2.2%, and inter-assay CV at 34.7 µg/mL and 39.59 µg/mL were 6.8% and 7.3%, respectively.

Plasma-soluble leptin receptor concentrations were measured by an ELISA technique (R&D Systems, Minneapolis, MN, USA) with a sensitivity of 0.06 ng ml⁻¹. Plasma leptin, plasma PYY_3–36 and plasma ghrelin were measured by radioimmunoassay (Millipore, Billerica, MA, USA). All quality controls (prepared by the manufacturer) were within acceptable limits. Radioimmunological determinations of total plasma GLP-1 were performed as described.^{26 (link), 27 (link), 28 (link)} The analytical detection limit was 1 pmol l⁻¹ and intra- and inter-assay coefficients of variation were <6% and <15%, respectively. Plasma glucose was measured with the glucose oxidase technique (YSI model 2300 STAT Plus; Yellow Springs Instruments, Yellow Springs, OH, USA). Serum insulin concentrations were measured using Immulite 2000 solid-phase chemiluminescent immunometric assays (Immulite 2000; Siemens, Erlangen, Germany). Fat percentage was assessed using dual-energy X-ray absorptiometry scanning (Hologic discovery A, Bedford, MA, USA). Blood pressure was measured using semi-automatic upper arm blood pressure monitor (Boso Mercurius E; Bosch+Sohn, Jungingen, Germany).

Urinary cotinine levels were measured (in ng/ml) using an IMMULITE^® 2000 (Siemens, USA) chemiluminescence assay employing an IMMULITE 2000 nicotine metabolite kit. The manufacturer indicated that 10 ng/ml was the limit for ETS exposure. A value below this threshold indicated “no ETS exposure” and a value of 10 ng/ml or greater indicated “ETS exposure.”