Advertisement

Effect of Hemolysis, High Bilirubin, Lipemia, Paraproteins, and System Factors on Therapeutic Drug Monitoring

  • Pradip Datta

Summary

Among the endogenous interferents affecting assay results, the most common are bilirubin, hemoglobin, lipids, and paraproteins. These interferents may affect therapeutic drug monitoring (TDM), drugs of abuse (DAU) testing, and toxicology assays of any format where the sample is used directly for analysis without any pretreatment of specimen. Immunoassays are commonly used in clinical laboratories where analyte-specific antibody or binding agents are used to estimate the analyte concentration in the specimen. Some enzyme and chemistry assays are also utilized in TDM and DAU analysis. Such assays use various types of signals, the most common being colorimetry, fluorimetry, and chemiluminescence. Assays may be prone to interference depending on the format or label used. Commercial assay kits report the result of such interference in the kit inserts (up to levels of >20 mg/dL bilirubin, >500 mg/dL hemoglobin, and >1000 mg/dL lipids). The interference is caused by the optical, fluorescent, or chemiluminescent properties of these interferents. Thus, bilirubin interferes by its absorption and fluorescence properties, hemoglobin by its absorption, fluorescence and chemiluminescence properties, and lipids interfere mostly from their light-scattering (turbidity) properties. Bilirubin and hemoglobin may also interfere because of side reactions in the assay. Modern auto-analyzers can detect all three interferents and flag the results. Flagged results should be carefully reviewed for the accuracy. Both hypo- and hyper-proteinemia can affect assay results. Paraproteins interfere in many assays by precipitating out during the sample blanking step thus producing false results. Another source of interference may be from probe (sample or reagents) or reaction cuvettes carryover contamination in random-access auto-analyzers. If the validity of test results is questioned, the assay should be repeated either by removing the interferent from the sample or by using different method which is known to suffer less from that type of interference.

Keywords

Bilirubin hemoglobin lipids interference assays 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Fonseca-Wolheim FD. Hemoglobin interference in the bichromatic spectrophotometry of NAD(P)H at 340/380 nm. Eur J Clin Chem Clin Biochem 1993;31:595–601.Google Scholar
  2. 2.
    NCCLS Recommendation (EP7-P), Interference testing in Clinical Chemistry, 1986 (Vol. 6, No. 13), pp 259–371.Google Scholar
  3. 3.
    Miller JM, Valdes R Jr. Methods for calculating crossreactivity in immunoassays. J Clin Immunoassay 1992;15:97–101.Google Scholar
  4. 4.
    Armedariz Y, Garcia S, Lopez R, et al. Hematocrit influences immunoassay performance for the measurement of tacrolimus in whole blood. Ther Drug Monit 2005;27:766–769.CrossRefGoogle Scholar
  5. 5.
    Tietz NW. Clinical Guide to Laboratory Tests. 3rd Ed. Philadelphia, PA: WB Saunders Company; 1995:88–91.Google Scholar
  6. 6.
    Perlstein MT, Thibert RJ, Watkins RJ, Zak B. Spectrophotometric study of bilirubin and hemoglobin interactions in several hydrogen peroxide generating procedures. Clin Chem 1977;23:1133 [Abstract].Google Scholar
  7. 7.
    Bertholf RL, Johannsen LM, Bazooband A, Mansouri V. False-positive acetaminophen results in a hyperbilirubinemic patient. Clin Chem 2003;49:695–698.PubMedCrossRefGoogle Scholar
  8. 8.
    Kellmeyer K, Yates C, Parker S, Hilligoss D. Bilirubin interference with kit determination of acetaminophen. Clin Chem 1982;28:554–555.PubMedGoogle Scholar
  9. 9.
    Wood FL, Earl JW, Nath C, Coakley JC. Falsely low vancomycin results using the Abbott TDx. Ann Clin Biochem 2000;37:411–413.PubMedCrossRefGoogle Scholar
  10. 10.
    Sonntag O, Glick MR. Serum-index und interferogram-ein neuer weg zur prufung und darstellung von interferengen durch serumchromogene. Lab Med 1989;13:77–82.Google Scholar
  11. 11.
    Wenk RE. Mechanism of interference by hemolysis in immunoassays and requirements for sample quality. Clin Chem 1998;44:2554.PubMedGoogle Scholar
  12. 12.
    Chance JJ, Norris EJ, Kroll MH. Mechanism of interference of a polymerized hemoglobin blood substitute in an alkaline phosphatase method. Clin Chem 2000;46:1331–1337.PubMedGoogle Scholar
  13. 13.
    Kroll MH. Evaluating interference caused by lipemia. Clin Chem 2004;50:1968–1969.PubMedCrossRefGoogle Scholar
  14. 14.
    Weber TH, Kaoyho KI, Tanner P. Endogenous interference in immunoassays in clinical chemistry. Scand J Clin Lab Invest Suppl 1990;201:77–82.PubMedGoogle Scholar
  15. 15.
    Bornhorst JA, Roberts RF, Roberts WL. Assay-specific differences in lipemic interference in native and Intralipid-supplemented samples. Clin Chem 2004;50:2197–201.PubMedCrossRefGoogle Scholar
  16. 16.
    Park Y, Grellner, Harris WS, Miles JM. A new method for the study of chylomicron kinetics in vivo. Am J Physiol Endocinol Metab 2000;279:E1258–263.Google Scholar
  17. 17.
    Kazmierczak SC, Catrou PG. Analytical interference, more than just a laboratory problem. Am J Clin Pathol 2000;113:9–11.PubMedCrossRefGoogle Scholar
  18. 18.
    Ezan E, Emmanuel A, Valente D, Grognet J-M. Effect of Variability of plasma interferentes on the accuracy of drug immunoassays. Ther Drug Monit 1997;19:212–218.PubMedCrossRefGoogle Scholar
  19. 19.
    Hullin DA. An IgM paraprotein causing a falsely low result in an enzymatic assay for acetaminophen. Clin Chem 1999;45:155–156.PubMedGoogle Scholar
  20. 20.
    Laurell CB, Waldenstrom J. Sera with exceptional appearance and the euglobulin reaction as screen test. Acta Med Scand Suppl 1961;367:97–100.Google Scholar
  21. 21.
    Dahlin J, Omar A, Ng HT, et al. An evaluation of automated serum indexing on the Roche Modular Serum Work Area. Clin Chem 2006;52:A104 [Abstract].CrossRefGoogle Scholar
  22. 22.
    Fossati P, Prencipe L. Serum triglycerides determined colorimetrically with an enzyme that produces hydrogen peroxide. Clin Chem 1982;28:2077.PubMedGoogle Scholar
  23. 23.
    Viljoen A, Cockrill G, Martin SC. The ability of the lipemic index to predict assay interference. Clin Chem 2006:52: A8 [Abstract].Google Scholar
  24. 24.
    ADVIA 1650 IgA, IgG, and IgM Method Sheets.Google Scholar
  25. 25.
    Dai J, Higgins T, Aistrope K, Peters C, Levine R, Datta P. Evaluation of the Bayer new immunoglobulin methods on the ADVIA® 1650 chemistry auto-analyzer. Clin Chem 2006:52:A154 [Abstract].CrossRefGoogle Scholar
  26. 26.
    Murphy L, Leamy A, O’Sullivan A, et al. Evaluation of new Olympus low interference triglyceride and uric acid assays on the Olympus AU400™, AU640/600™, and AU2700/5400™ analyzers. Clin Chem 2006:52:A160 [Abstract].CrossRefGoogle Scholar
  27. 27.
    Balion CM, Champagne PA, Ali ACY. Evaluation of hemoglobind for removal of O-raffinose cross-linked hemoglobin (Hemolink) from serum. Clin Chem 1997;43:1796–1798.PubMedGoogle Scholar

Copyright information

© Humana Press Inc 2008

Authors and Affiliations

  • Pradip Datta

There are no affiliations available

Personalised recommendations