Interferences from blood collection tube components on clinical chemistry assays

Journal Article

Larry J Kricka,

Address correspondence to this author at: Department of Pathology and Laboratory Medicine, University of Pennsylvania Medical Center, 3400 Spruce Street, Philadelphia, PA 19104-4283.

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Jason Y Park

Department of Pathology & Laboratory Medicine

, University of Pennsylvania Medical Center, Philadelphia, PA

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Published:

01 October 2005

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Immunoassay interferences are diverse in scope (1)(2)(3)(4)(5)(6)(7)(8) and are the subject of several recent large-scale studies (9)(10), opinions, and editorials (6)(11). Most interferences originate from components of the sample (e.g., human antianimal antibodies, lipid, bilirubin, drug metabolites) that interact with assay reagents or the detection system.

The latest interference to rear its ugly head has been an interference originating from an additive in a blood collection tube (12)(13)(14). In this issue of Clinical Chemistry, Remaley et al. (13) have extended their original work (12) on this problem and have now identified a common tube surfactant as the probable interferent. They show that Silwet™ L-720, an organosilane surfactant additive to Becton Dickinson Vacutainer® SST™ blood collection tubes, causes interferences by desorbing capture antibodies from the solid phase used in the Immulite total triiodothyronine immunoassay. This desorption effect was supported by sodium dodecyl sulfate–polyacrylamide gel electrophoresis and by immunoblotting analysis of Silwet™ L-720 eluates of the solid-phase antibody used in the Immulite assays.

Now that the source of this interference has been identified, a pertinent question is this: “How can this type of interference be detected in the future?”

Clearly, now that blood collection tube additives have been identified as a possible source of interference in immunoassays, manufacturers of blood collection tubes and immunoassay tests should implement additional quality-control measures. In addition, various control measures may be prudent in the clinical laboratory. One action could be increased vigilance of the running means of patients’ results, to detect an unexpected shift. However, this may be of limited or no use for endocrine assays because the range of patient values can be very large in the population tested (e.g., follicle-stimulating hormone concentrations in pre- and postmenopausal women vary over 10-fold and 100-fold ranges, respectively). Hence, there is a large spread of values that would obscure shifts in assay values caused by interference. Another action might be to adhere strictly to the basic tenet of quality control, namely, that the control sample should be treated in exactly the same manner as a specimen from a patient. In most, if not all, clinical laboratories, quality-control samples are poured from the bottle into an assay tube and then placed on the analyzer for analysis. Unlike the specimen from the patient, they do not encounter the contents of a blood collection tube. It would thus seem expedient to analyze samples of quality-control serum that have been poured into a blood collection tube and then processed along with patients’ specimens. Comparison of results for control sera that have and have not been exposed to blood collection tubes should reveal adverse effects resulting from additives in the tubes. This strategy would provide a means to detect future interferences resulting from changes in the formulation of additives in blood collection tubes. However, the diverse production lots of blood collection tubes used in various in- and outpatient locations also obscure lot-dependent interferences. It seems more feasible to have manufacturers expose quality-control sera to blood collection tubes on a lot-by-lot basis.

In the meantime, we need to remain vigilant for other immunoassay interferences. Nutritional supplements such as herbal medicines are widely used in the United States (15) and are a potential source of interfering substances that have not been thoroughly investigated. Indeed, assay interferences attributed to traditional Chinese medicines have already been reported in digoxin immunoassays (16)(17)(18)(19). An additive-attributable assay aberration is not the first interference to be reported in immunoassays, and it certainly will not be the last.

1

Selby C. Interference in immunoassay.

Ann Clin Biochem

1999

;

36

:

704

-721.

2

Walker PL, Cawood ML, Barth JH. Interference in immunoassay is an underestimated problem.

Ann Clin Biochem

2002

;

39

:

366

-373.

3

Klee GG. Interferences in hormone immunoassays.

Clin Lab Med

2004

;

24

:

1

-18.

4

Kricka LJ. Human anti-animal antibody interferences in immunological assays.

Clin Chem

1999

;

45

:

942

-956.

5

Levinson SS, Miller JJ. Towards a better understanding of heterophile (and the like) antibody interference with modern immunoassays.

Clin Chim Acta

2002

;

325

:

1

-15.

6

Diamandis EP. Immunoassay interference: a relatively rare but still important problem.

Clin Biochem

2004

;

37

:

331

-332.

7

Weber TH, Kapyaho KI, Tanner P. Endogenous interference in immunoassays in clinical chemistry. A review.

Scand J Clin Lab Invest Suppl

1990

;

201

:

77

-82.

8

Emerson JF, Ngo G, Emerson SS. Screening for interference in immunoassays.

Clin Chem

2003

;

49

:

1163

-1169.

9

Preissner CM, Dodge LA, O’Kane DJ, Singh RJ, Grebe SK. Prevalence of heterophilic antibody interference in eight automated tumor marker immunoassays.

Clin Chem

2005

;

51

:

208

-210.

10

Marks V. False-positive immunoassay results: a multicenter survey of erroneous immunoassay results from assays of 74 analytes in 10 donors from 66 laboratories in seven countries.

Clin Chem

2002

;

48

:

2008

-2016.

11

Ismail AAA. A radical approach is needed to eliminate interference from endogenous antibodies in immunoassays.

Clin Chem

2005

;

51

:

25

-26.

12

Bowen RA, Chan Y, Cohen J, Rehak NN, Hortin GL, Csako G, et al. Effect of blood collection tubes on total triiodothyronine and other laboratory assays.

Clin Chem

2005

;

51

:

424

-433.

13

Bowen RAR, Chan Y, Ruddel ME, Hortin GL, Csako G, Demosky SJ, Jr, et al. Immunoassay interference by a commonly used blood collection tube additive, the organosilicone surfactant Silwet L-720.

Clin Chem

2005

;

51

:

1874

-1882.

15

Kaufman DW, Kelly JP, Rosenberg L, Anderson TE, Mitchell AA. Recent patterns of medication use in the ambulatory adult population of the United States: the Slone survey.

JAMA

2002

;

287

:

337

-344.

16

Chow L, Johnson M, Wells A, Dasgupta A. Effect of the traditional Chinese medicines Chan Su, Lu-Shen-Wan, Dan Shen, and Asian ginseng on serum digoxin measurement by Tina-quant (Roche) and Synchron LX system (Beckman) digoxin immunoassays.

J Clin Lab Anal

2003

;

17

:

22

-27.

17

Datta P, Dasgupta A. Effect of Chinese medicines Chan Su and Danshen on EMIT 2000 and Randox digoxin immunoassays: wide variation in digoxin-like immunoreactivity and magnitude of interference in digoxin measurement by different brands of the same product.

Ther Drug Monit

2002

;

24

:

637

-644.

18

Dasgupta A, Actor JK, Olsen M, Wells A, Datta P. In vivo digoxin-like immunoreactivity in mice and interference of Chinese medicine Danshen in serum digoxin measurement: elimination of interference by using a chemiluminescent assay.

Clin Chim Acta

2002

;

317

:

231

-234.

19

Wahed A, Dasgupta A. Positive and negative in vitro interference of Chinese medicine dan shen in serum digoxin measurement. Elimination of interference by monitoring free digoxin concentration.

Am J Clin Pathol

2001

;

116

:

403

-408.

© 2005 The American Association for Clinical Chemistry

© 2005 The American Association for Clinical Chemistry

What other factors of specimen collection can have an adverse effect on chemistry analytes?

Components from blood collection tubes, such as stoppers, lubricants, surfactants, and separator gels, can leach into specimens and/or adsorb analytes from a specimen; special tube additives may also alter analyte stability.

What is the consequence of EDTA tubes not mixed properly?

A full EDTA tube should be submitted. Partially filled EDTA tubes affect the cells because EDTA is hypertonic (e.g. echinocytes will form in underfilled EDTA tubes and red cells shrink, decreasing the mean cell volume and increasing the mean cell corpuscular hemoglobin concentration).

Why should EDTA tubes be avoided when collecting samples for calcium measurement?

Citrate (blue top) and EDTA (lavender top) cannot be used for chemistry panels because they chelate minerals (e.g. calcium) and interfere with the tests.

Which anticoagulant is best for specific chemistry assays?

EDTA (Ethylenediaminetetraacetic acid).
Indications: This is useful for the hematological examination. ... .
EDTA is used as a disodium or dipotassium salt. Mostly potassium EDTA is used as an anticoagulant, recommended for hematology studies. ... .
Mechanism of action:.