Veterinary Free T4. For use on IMMULITE 2000 systems

Transcription

1 Veterinary Free T4 For use on IMMULITE 2000 systems

2 IMMULITE 2000 Free T4 English Intended Use: For animal use only with the IMMULITE 2000 Systems Analyzers for the quantitative measurement of non-protein-bound thyroxine (free T4) in serum, as an aid in the clinical assessment of thyroid status in animals. Catalog Number: L2KVF42 (200 tests) Test Code: VF4 Color: Violet Summary and Explanation The principal thyroid hormone, thyroxine (T4), circulates almost entirely bound to carrier proteins, including 3 globulins and albumin in dogs. The serum free T4 represents the small (<0.1%) biologically active fraction of the total T4. Altered carrier protein concentrations induce changes in total T4 levels, and free T4 concentrations tend to stay within a tight range. For this reason, total T4 measurements do not always reflect thyroid status. Since abnormal T4 levels may signify either abnormal thyroid function or carrier protein variation (physiological or pathological), free T4 measurements more highly correlate with thyroid status than total T4 measurements. Hypothyroidism is considered to be a common endocrine disorder in dogs, whereas hyperthyroidism in this species is relatively unknown. Most cases of canine hypothyroidism are primary in nature, involving impaired production of the thyroid hormones, T4 and T3. In this condition, elevated TSH levels are expected. Secondary or tertiary hypothyroidism, where thyroid hormone production is low as a consequence of hypothalamic or pituitary disease, is believed to account for less than 5% of canine hypothyroidism cases. In the latter conditions, lowered levels of TSH would be expected. Usually, hypothyroidism in dogs is suspected on the basis of clinical history and the presence of lowered levels of thyroid hormones. However, suppressed thyroid hormone levels are nonspecific indicators of the disease, since they are often observed in nonthyroidal illnesses. Hyperthyroidism (overactive thyroid glands) is a very common disorder of older cats. It is caused by an increase in production of thyroid hormones from the thyroid glands. Principle of the Procedure IMMULITE 2000 Veterinary Free T4 is a solid phase, chemiluminescent, competitive analog immunoassay. The solid phase (bead) is coated with monoclonal murine anti-t4 antibody. The liquid phase consists of alkaline phosphatase (bovine calf intestine) conjugated to T4. The animal sample and the reagent are incubated together with the coated bead for 30 minutes. During this time, free T4 in the sample competes with enzymeconjugated T4 in the reagent for a limited number of antibody binding sites on the bead. Unbound patient sample and enzyme conjugate are then removed by centrifugal washes. Finally, chemiluminescent substrate is added to the reaction tube containing the bead, and the signal is generated in proportion to the bound enzyme. The IMMULITE 2000 Veterinary Free T4 procedure is a direct or single test assay, in the sense that its results are not calculated as a function of total T4, but interpolated from a (stored) standard curve calibrated in terms of free T4 concentrations. 6 In this respect it differs from classic equilibrium dialysis methods and from so-called free T4 index determinations as well. It requires neither a pre-incubation step nor preliminary isolation of the free fraction by dialysis or column chromatography. The assay employs several features to preserve the equilibrium between free and protein-bound T4 and to measure accurately the unbound fraction. First, the T4 analog has a nondetectable binding affinity for TBG. Second, the assay's specific antibody binds T4 about as tightly as albumin binds T4 and thereby avoids stripping the hormone from thyroid binding proteins. Finally, the procedure operates at physiological temperature, ph and ionic strength. 2 IMMULITE 2000 Veterinary Free T4 (PIL2KVF4-3, )

3 Incubation Cycles: 1 30 minutes Time to First Result: 35 minutes. Specimen Collection Collect animal blood by venipuncture into plain tubes and separate the serum from the cells. The use of an ultracentrifuge is recommended to clear lipemic samples. Hemolyzed samples may indicate mistreatment of a specimen before receipt by the laboratory; hence the results should be interpreted with caution. Centrifuging serum samples before a complete clot forms may result in the presence of fibrin. To prevent erroneous results due to the presence of fibrin, ensure that complete clot formation has taken place prior to centrifugation of samples. Blood collection tubes from different manufacturers may yield differing values, depending on materials and additives, including gel or physical barriers, clot activators and/or anticoagulants. Volume Required: 10 µl animal serum. Storage. 7 days at 2 8 C, or 1 month frozen at 20 C. 9 Warnings and Precautions For animal use only. Reagents: Store at 2 8 C. Dispose of in accordance with applicable laws. Chemiluminescent Substrate: Avoid contamination and exposure to direct sunlight. (See insert.) Water: Use distilled or deionized water. Materials Supplied Components are a matched set. The barcode labels are needed for the assay. Veterinary Free T4 Bead Pack (L2VF412) With barcode. 200 beads, coated with monoclonal murine anti-t4 antibody. Stable at 2 8 C until expiration date. L2KVF42: 1 pack. Veterinary Free T4 Reagent Wedge (L2VF4A2) With barcode ml alkaline phosphatase (bovine calf intestine) conjugated to T4 in buffer. Stable at 2 8 C until the expiration date. L2KVF42: 1 wedge. Before use, tear off the top of the label at the perforations, without damaging the barcode. Remove the foil seal from the top of wedge; snap the sliding cover down into the ramps on the reagent lid. Veterinary Free T4 Adjustors (LVF4L, LVF4H) Two vials (Low and High) of lyophilized free T4 in processed canine serum. Reconstitute each vial with 2.0 ml distilled or deionized water. Mix by gentle swirling or inversion until the lyophilized material is fully dissolved. Stable for 4 months (aliquotted) at 20 C. L2KVF42: 1 set. Before running adjustors, place the appropriate Aliquot Labels (supplied with the kit) on test tubes, so that the barcodes can be read by the on-board reader. Kit Components Supplied Separately L2SUBM: Chemiluminescent Substrate L2PWSM: Probe Wash L2KPM: Probe Cleaning Kit LRXT: Reaction Tubes (disposable) K9TCM: A bi-level, canine serum-based control module, containing free T4 as one of 3 assayed constituents. Also Required Sample transfer pipets; distilled or deionized water; controls. Assay Procedure Note that for optimal performance, it is important to perform all routine maintenance procedures as defined in the IMMULITE 2000 Operator's Manual. See the IMMULITE 2000 Operator's Manual for: preparation, setup, adjustment, assay and quality control procedures. Recommended Adjustment Interval: 2 weeks IMMULITE 2000 Veterinary Free T4 (PIL2KVF4-3, ) 3

4 Quality Control Samples: Use controls or serum pools with at least two levels of free T4. Expected Values Each laboratory should establish its own reference ranges. Performance Data See Tables and Graphs for data representative of the assay's performance. Results are expressed in ng/dl. (Unless otherwise noted, all were generated on canine or feline serum samples collected in tubes without gel barriers or clotpromoting additives.) Conversion Factor: ng/dl pmol/l Reportable Range: ng/dl ( pmol/l). The assay is traceable to an internal standard manufactured using qualified materials and measurement procedures. Analytical Sensitivity: Limit of Blank (highest value expected for a sample with no analyte; determined in accordance with CLSI EP17-A 7 ): 0.04 ng/dl (0.51 pmol/l). Limit of Detection (lowest detectable concentration; determined in accordance with CLSI EP17-A 7 ): 0.10 ng/dl (1.29 pmol/l). Functional Sensitivity: (concentration with 20% coefficient of variation (CV) determined in accordance with CLSI EP5-A2 8 ): 0.25 ng/dl (3.2 pmol/l). Precision: Samples were assayed in duplicate over the course of 10 days, four runs per day, for a total of 40 runs and 80 replicates. (See Precision table.) Specificity: The antibodies used in the IMMULITE 2000 Veterinary Free T4 procedure are highly specific for free T4. (See Specificity table.) Effect of Oleic Acid: No significant effect. (See Effect of Oleic Acid table.) References 1) Ferguson DC. Thyroid function tests in the dog. Veterinary Clinics of North America. Small Animal Practice 1984; 14: ) Panciera DL. Hypothyroidism in dogs; 66 cases ( JAVMA 1994; 204: ) Nesbitt GH, Izzo J, Peterson L, Wilkins RJ. Canine hypothyroidism; A retrospective study of 108 cases. JAVMA 1980; 177: ) Feline advisory bureau (fab) information sheet; Hyperthyroidism in cats, updated Novermber FAB, Taeselbury, High Street, Tisbury, Wiltshire, UK, SP3 6LD. 5) Witherspoon LR, El Shami AS, et al. Chemically blocked analog assays for free thyronines. Clin Chem 1988;34:9 16 and ) Wosilait WD. A theoretical analysis of the distribution of thyroxine among sites on thyroid binding globulin, thyroid binding prealbumin and serum albumin. Res Commun Chem Pathol Pharmacol 1977;16: ) CLSI. Protocols for the Dtermination of Limits of Detection and Limits of Quantitation; Approved Guideline. CLSI document EP17-A Vol. 24 (No. 34). CLSI, ) Evaluation of Precision Performance of Quantitative Measurement Methods; Approved Guideline-Second Edition. CLSI document EP5- A2. CLSI, ) Tietz NW, editor. Clinical guide to laboratory tests. 4rd ed. Philadelphia: W.B. Saunders, 1996: Technical Assistance In the United States, contact Siemens Healthcare Diagnostics Technical Services department. Tel: Outside the United States, contact your National Distributor. The Quality System of Siemens Healthcare Diagnostics Products Ltd. is certified to ISO 13485:2003. Tables and Graphs Precision (ng/dl) Within-Run Total Mean SD CV SD CV % % % % % % % % % % 4 IMMULITE 2000 Veterinary Free T4 (PIL2KVF4-3, )

5 Specificity ng/dl Added Albumin Apparent ng/dl %Crossreactivity 5,000,000, ND D-T4 1,000 ND ND 3,5-Diiodo-L-thyronine 10,000 ND ND 3,5-Diiodo-DL-thyrosine 100, % L-T3 100, % 5,5-Diphenylhydantoin 4,000, ND 3-Monoiodo-L-tyrosine 10,000 ND ND Salicylic Acid 50,000,000 ND ND 3,3',5,5'-Tetraiodothyroacetic Acid 2,000 ND ND 6-n-Propyl-2-thiouracil 1,000 ND ND Methimazole 1,000,000 ND ND Phenylbutazone 1,000,000 ND ND ND: not detectable. Effect of Oleic Acid (ng/dl) PIL2KVF4 3 Changes in this Edition: cc#19681: Created new IFU. cc#19681a: Revised the Limit of Blank and Limit of Detection values. Understanding the Symbols The following symbols may appear on the product labeling: Symbol Definition Catalog Number Manufacturer Consult instructions for use Caution! Potential Biohazard Temperature limitation (2 8 C) Upper limit of temperature ( -20 C) Lower limit of temperature ( 2 C) Do not freeze (> 0 C) Oleic Acid Added (mmol/l) Free T4 Measured 10 ND ND: not detectable. Do not reuse IMMULITE is a trademark of Siemens Healthcare Diagnostics Siemens Healthcare Diagnostics Inc. All rights reserved. Origin: UK Siemens Healthcare Diagnostics Products Ltd. Llanberis, Gwynedd LL55 4EL United Kingdom LOT Keep away from sunlight Batch code Contains sufficient for (n) tests IMMULITE 2000 Veterinary Free T4 (PIL2KVF4-3, ) 5

6 Symbol Definition Date format (year-month) Use by Harmful Symbol Definition CONTROL Control CONTROL 1 CONTROL 2 CONTROL 3 Corrosive CONTROL + Positive Control Toxic CONTROL + L Low Positive Control Dangerous for the environment CONTROL Negative Control CONTROL AB Control Antibody BEAD PACK Bead Pack PRE A Pretreatment Solution TEST UNIT Test Unit PRE B REAG WEDGE Reagent Wedge DITHIOTHREITOL Dithiothreitol Solution REAG WEDGE A REAG WEDGE B REAG WEDGE D BORATE-KCN BUF Borate-KCN Buffer Solution ADJUSTOR Adjustor ADJUSTOR L Adjustor, low ADJUSTOR H Adjustor, high ADJUSTOR AB Adjustor Antibody DIL Sample Diluent 6 IMMULITE 2000 Veterinary Free T4 (PIL2KVF4-3, )