Stability of 35 biochemical and immunological routine tests after 10 hours storage and transport of human whole blood at 21°C

Figures & data

Table I. Analytes, number of samples and range of values.

Short name	Analyte	Unit	IUPAC (NPU)^†	n	Baseline values Median (range)	Local reference intervals (adults)
ALAT	Alanine aminotransferase	U/L	19651	56	18 (6–173)	10–70
ALB	Albumin	g/L	19673	56	37 (17–46)	34–48
AMYL	Amylase	U/L	19653	56	23 (5–218)	10–65
ATRYP	Antitrypsin	g/L	19692	34	1.83 (0.57–3.43)	0.97–1.68
B12*	Cobalamin	pmol/L	01700	49	406 (137–1476)	200–600
BASP	Alkaline phosphatase	U/L	19655	55	62 (33–503)	35–105
BILI	Bilirubin	μmol/L	01370	56	9 (4–87)	5–25
CA	Calcium	mmol/L	01443	56	2.33 (1.87–2.64)	2.20–2.55
CHOL	Cholesterol	mmol/L	01566	56	4.4 (2.0–7.2)	< 5.0^‡
CK	Creatine kinase	U/L	19656	55	74 (7–551)	50–270
CO2	Total carbon dioxide	mmol/L	01472	56	29 (16–41)	23–32
CREA	Creatinine	μmol/L	18016	56	69 (31–215)	45–105
CRP	c-Reactive protein	mg/L	19748	56	6.7 (0.2–217.5)	< 8.0
F-T3*	Free triiodothyronine	pmol/L	03625	50	3.7 (1.7–6.4)	3.9–6.8
F-T4*	Free thyroxine	pmol/L	03579	50	18.3 (11.7–33.1)	12.0–21.0
Fe	Iron	μmol/L	02508	55	12 (3–29)	9–34
FER*	Ferritin	μg/L	19763	50	309 (35–3716)	15–355
FOL*	Folate	nmol/L	02070	48	12 (2–39)	> 9
GGT	γ-glutamyl transferase	U/L	19657	55	32 (11–442)	10–115
HAPT	Haptoglobin	g/L	19788	54	1.35 (0.20–4.33)	0.35–2.05
HDL-C	HDL-cholesterol	mmol/L	01567	56	1.2 (0.2–2.1)	> 1.0^‡
IgA	Immunoglobulin A	g/L	19795	56	1.94 (0.86–5.21)	0.80–4.90
IgG	Immunoglobulin G	g/L	19814	56	9.9 (3.8–21.3)	6.1–15.7
IgM	Immunoglobulin M	g/L	19825	55	0.82 (0.13–2.27)	0.39–2.30
K	Potassium	mmol/L	03230	56	3.8 (3.1–4.8)	3.5–4.6
LD	Lactate dehydrogenase	U/L	19658	56	173 (95–609)	105–255
Na	Sodium	mmol/L	03429	56	139 (127–145)	137–145
OROS	Orosomucoid	g/L	19873	54	0.84 (0.28–2.45)	0.45–1.17
P	Phosphate	mmol/L	03096	56	1.02 (0.51–1.60)	0.71–1.53
PSA*	Prostate specific antigen	μg/L	08669	31	0.8 (0.1–11.6)	< 0.3
TGLY	Triglycerides	mmol/L	04094	56	1.1 (0.4–6.2)	< 2.0^‡
TRANS	Transferrin	μmol/L	03607	55	27 (9–47)	24–41
TSH*	Thyroid stimulating hormone	mIU/L	03577	50	1.29 (0.020–8.72)	0.300–4.50
URATE	Uric acid	mmol/L	03688	56	0.25 (0.12–0.73)	0.15–0.48
UREA	Urea	mmol/L	01459	56	5.4 (2.6–25.7)	2.6–8.1

*Analysis performed on Advia Centaur XP using whole blood in serum tubes. For the other analytes analysis was performed on Architect c8000 using whole blood in lithium-heparin tubes. ^†IUPAC, International Union of Pure and Applied Chemistry; NPU, Nomenclature for Properties and Units. The NPU terminology is in national use in Denmark, for communication and recording of clinical laboratory information. http://www.ssi.dk/EnglishNPU. ^‡Decision limit.

Table II. Imprecision (CV) and bias for 35 analytes. Results obtained after storage of whole blood at 21°C was compared to baseline results.

	CV (%)		Bias (%)		Paired t-test p value^††
Analyte	CV^†	Analytical^‡/goal^§	Mean deviation (95% CI)^||	Goal^¶
ALAT	2.4	2.7/9.0	− 1.7 (− 2.9;− 0.4)	12.0**	0.0034
ALB	1.5	0.9/3.2**	0.2 (0;0.5)	2.2**	0.067
AMYL	1.1	2.4/5.9	− 0.8 (− 1.2;− 0.3)	8.0	< 0.0001
ATRYP	2.9	0.9/4.5	− 0.7 (− 1.5;0.1)	6.5	0.12
B12*	6.4	6.4/7.5	− 3.2 (− 5.6;− 0.8)	17.7	0.015
BASP	1.2	2.2/4.8	0.2 (− 0.3;0.7)	6.4	0.31
BILI	2.1	3.2/6.4**	1.0 (0.2;1.9)	10.0**	0.11
CA	1.1	1.0/2.5**	1.0 (0.7;1.3)	2.0**	< 0.0001
CHOL	1.3	0.5/3.0**	0.6 (0.2;1.1)	4.0	0.0085
CK	1.4	0.8/5.7	− 0.7 (− 1.3;− 0.1)	11.5	0.0023
CO2	3.4	5.0/6.0**	1.2 (0.0;2.4)	5.0**	0.16
CREA	1.1	1.3/2.7**	− 0.1 (− 0.6;0.3)	3.8**	0.50
CRP	1.8	1.8/5.0**	2.6 (− 0.5;5.7)	5.0**	0.046
F-T3*	2.4	2.2/7.5**	0.8 (− 0.3;1.8)	7.2	0.28
F-T4*	4.6	4.6/7.5**	2.1 (0.3;3.9)	3.6**	0.039
Fe	3.7	1.6/6.7**	6.8 (5.8;8.2)	8.8	< 0.0001
FER*	7.0	4.3/7.1	− 1.1 (− 2.7;0.5)	5.2	0.039
FOL*	20.5	6.6/12.0	− 13.7 (− 19.1;− 8.3)	19.2	0.0007
GGT	2.6	1.6/3.5	− 0.8 (− 2.1;0.6)	5.4	0.62
HAPT	1.7	1.4/5.1	0.1 (− 0.4;0.6)	10.4	0.72
HDL-C	2.9	1.8/3.6	4.6 (3.7;5.4)	5.2	< 0.0001
IgA	2.1	1.3/2.7	1.9 (1.4;2.3)	9.1	< 0.0001
IgG	1.0	0.9/2.3	0.2 (− 0.2;0.5)	4.3	0.75
IgM	1.5	2.5/4.5**	1.7 (0.9;2.5)	11.9	0.0001
K	2.9	0.8/2.4	1.2 (0.1;2.2)	1.8	0.040
LD	4.5	3.1/5.0**	1.0 (− 1.3;3.1)	4.3	0.55
Na	0.4	0.7/1.0**	0.3 (0.1;0.4)	0.6**	0.0003
OROS	1.5	0.9/5.7	0.8 (0.1;1.5)	6.8	0.017
P	9.0	1.8/4.3	− 11.2 (− 12.4;− 10.0)	3.2	< 0.0001
PSA*	3.4	3.4/9.1	− 0.4 (− 2.0;1.2)	18.7	0.083
TGLY	2.0	1.0/5.3**	− 0.9 (− 1.7;− 0.1)	5.4**	0.018
TRANS	1.5	0.9/2.3	1.8 (1.4;2.2)	2.6**	< 0.0001
TSH*	9.2	4.9/9.7	6.0 (3.4;8.7)	7.8	0.0040
URATE	1.6	1.3/4.3**	1.5 (0.9;2.1)	4.8**	< 0.0001
UREA	1.0	1.9/6.2	− 0.2 (− 0.6;0.2)	5.5	0.072

*Analysis performed on Advia Centaur XP using whole blood in serum tubes. For the other analytes analysis was performed on Architect c8000 using whole blood in lithium-heparin tubes. ^†CV calculation based on measurements at baseline and after 10 h of storage. ^‡Annual (2011) average CV of laboratory routine quality control samples. ^§CV goals used in evaluating analytical variation in laboratory routine quality control. Goals were generally based on biological variation from http://westgard.com/biodatabase1.htm and calculated as described by Fraser et al. [18]. **denotes goals where empirically based modifications to the three stated levels of performance were used. ^||Mean deviation % between baseline and 10-h values and 95% confidence interval (shown as confidence limits). ^¶Bias goals used in evaluating systematic differences in laboratory routine quality control. See ^§CV goals for further details. ^††p-values for testing baseline values against values obtained after 10 h of storage of whole blood.

Figure 1. Imprecision and bias calculated for results obtained at baseline and after 10 h of storage of whole blood (in lithium-heparin or serum tubes). Data on imprecision (A) shows CV calculated from results obtained at baseline and after storage of whole blood in lithium-heparin or serum tubes at 21°C for 10 h. The analytical imprecision is indicated as grey columns and the goal imprecision as the total height of the columns. Data on bias (B) shows the mean bias between baseline and results obtained after storage of whole blood for 10 h. The columns indicate bias goal. Data for analytical- and goal-CV as well as bias goal are indicated for each analyte in Table II.

Figure 2. Bland-Altman plots of results obtained after storage of whole blood (in lithium-heparin or serum tubes) for 10 h prior to analysis as compared to results at baseline. Fraction: Ratio between baseline results and results at 10 h. Indicated on each figure is the line of identity, i.e. baseline/10 h = 1.0 (bold dashed line), the analytical CV (thin dashed line), goal-CV (full drawn thin line) and the reference interval (shaded area). Data for analytical- and goal-CVs are indicated for each analyte in Table II.

Fraser CG, Hyltoft PP, Libeer JC, Ricos C. Proposals for setting generally applicable quality goals solely based on biology. Ann Clin Biochem 1997;34(Pt 1):8–12.

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