Definition of the upper reference limit for thyroglobulin antibodies according to the National Academy of Clinical Biochemistry guidelines: comparison of eleven different automated methods

Table 2 Summary statistics of TgAb measurements for each method

Method	AIA	ARC	CEN^a	CL2	COB	IMM	KRY^a	LIA	LUM	MAG	PHA
No.	120	120	120	120	120	120	120	120	120	120	120
Mean (95% CI)	1.56 1.18–1.95	1.81 1.58–2.03	10.93 9.74–12.13	0.53 0.43–0.63	14.23 12.87–15.58	1.28 1.04–1.53	10.79 9.43–12.14	10.38 9.57–11.2	7.94 7.2–8.69	15.61 14.19–17.03	12.05 11.09–13.01
SD	2.12	1.26	6.61	0.56	7.52	1.36	7.48	4.49	4.12	7.87	5.33
RSD	1.36	0.7	0.6	1.06	0.53	1.05	0.69	0.43	0.52	0.50	0.44
Median (95% CI)	0.91 0.8–1.08	1.51 1.39–1.61	9.61 8.81–10.6	0.4 0.32–0.46	12.56 11.93–12.84	1.03 0.81–1.21	8.41 7.27–10.49	9.4 9.11–9.81	6.87 6.36–7.58	13.35 12.38–15.07	11 10–11
25th–75th p	0.63–1.48	1.21–1.92	6.96–13.83	0.24–0.59	11.5–13.61	0.36–1.65	5.04–15.15	8.66–10.42	5.63–8.64	10.05–17.97	10–13.5
2.5th–97.5th p	0.36–6.75	0.73–5.14	1.64–26.25	0.1–2.25	10.31–41.15	0.02–4.23	1.22–29.94	7.50–21.79	5.15–20.56	10.05–34.23	6–24.5
Normal distribution	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001

Mean, SD, median, percentiles are expressed in IU/mL
AIA AIA-2000, Tosoh Bioscience, ARC Architect, Abbott Diagnostics, CEN Advia Centaur XP, Siemens Healthineers, CI confidence intervals, CL2 AIA CL-2400, Tosoh Bioscience, COB Cobas 6000, Roche Diagnostics, IMM Immulite 2000 XPi, Siemens Healthineers, KRY Kryptor, Thermo Fisher Scientific BRAHMS, LIA Liaison XL, Diasorin, LUM Lumipulse G, Fujirebio, MAG Maglumi 2000 Plus, Snibe, No. number, p percentile, PHA Phadia 250, Phadia AB, Thermo Fisher Scientific, RSD relative standard deviation, SD standard deviation
^aThe results obtained with Advia Centaur XP and Kryptor Compact Plus are expressed as arbitrary units (AU/mL); to obtain IU multiply for the conversion factor 2.8 (CEN) and 7.14 (KRY)

ISSN: 2038-3274