Comparison of Auto RPR Plus and Auto TPIM Plus with Mediace RPR and Abbott Syphilis TP for Serologic Diagnosis of Syphilis

Hyun-Jeong Kim; Eun-Hee Nah; Seon Cho; So-Young Jeong

doi:10.3343/lmo.2018.8.3.87

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Kim, Nah, Cho, and Jeong: Comparison of Auto RPR Plus and Auto TPIM Plus with Mediace RPR and Abbott Syphilis TP for Serologic Diagnosis of Syphilis

Original Article

Lab Med Online 2018;8(3):87-93.

Published online: 19 July 2018

DOI: https://doi.org/10.3343/lmo.2018.8.3.87

Comparison of Auto RPR Plus and Auto TPIM Plus with Mediace RPR and Abbott Syphilis TP for Serologic Diagnosis of Syphilis

Hyun-Jeong Kim, M.D.¹, Eun-Hee Nah, M.D.², Seon Cho, M.S.², So-Young Jeong, M.T.¹

¹Department of Laboratory Medicine, Korea Association of Health Promotion, Seoul, Korea

²Health Promotion Research Institute, Korea Association of Health Promotion, Seoul, Korea

Corresponding author: Eun-Hee Nah Health Promotion Research Institute, Korea Association of Health Promotion, 350 Hwagok-ro, Gangseo-gu, Seoul 07653, Korea Tel: +82-2-2600-0107, Fax: +82-2-2690-4915, E-mail: cellonah@hanmail.net

Received 22 March 2017 Revised 15 January 2018 Accepted 7 February 2018

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Background:

Serologic testing is considered a standard method for syphilis diagnosis. We compared Auto RPR Plus and Auto TPIM Plus with previously developed assays.

Methods:

The precision around the cutoff, linearity, and recovery rate of Auto RPR Plus and Auto TPIM Plus was evaluated using their positive/ negative control materials. The results of these two tests were compared with those of Mediace RPR and Abbott Syphilis TP using 431 remnant serum samples collected from people who underwent medical examinations.

Results:

The within-run precisions (coefficient of variation, CV values) of negative/positive control materials of Auto RPR Plus, Mediace RPR, Auto TPIM Plus and Abbott Syphilis TP were 15.7/2.3%, 20.4/2.3%, -/2.7%, and 8.5/2.3%, respectively; between-run precisions were 67.7/3.3%, 39.1/3.4%, -/4.0%, and 7.0/1.5%, respectively. Auto RPR Plus showed better precision around the cutoff level (1.0 U) compared to Mediace RPR (7.2–7.3% vs. 12.2–14.3%). The CVs of Auto TPIM Plus around the cutoff (10.0 U) were 13.5% at 10.5 U and 6.6% at 12.5 U. Agreement rates between Auto RPR Plus and Mediace RPR and between Auto TPIM Plus and Abbott Syphilis TP were 97.2% and 98.4%, respectively. However, twelve samples showed discrepant results for Auto RPR Plus (-)/Mediace RPR (+) and false-positive Mediace RPR results could not be excluded around the cutoff of 1.0 U.

Conclusions:

Auto RPR Plus showing good precision near the cutoff can be used for syphilis screening in health checkups. However, Auto TPIM Plus needs improvement in precision and adjusting the cutoff to be used for syphilis screening.

Keywords: Syphilis, Serodiagnosis, Auto RPR Plus, Auto TPIM Plus

REFERENCES

1.The Korean Society for Laboratory Medicine. Laboratory Medicine. 5th ed.Seoul: Beommun Education;2014. p. 845–6.

2.Park MJ., Park PW., Seo YH., Ahn JY., Kim KH., Seo JY, et al. Evaluation of AutoLab rapid plasma reagin and AutoLab Treponema pallidum latex agglutination for syphilis infection testing. J Lab Med Qual Assur. 2015. 37:29–36.

3.Tong ML., Lin LR., Liu LL., Zhang HL., Huang SJ., Chen YY, et al. Analysis of 3 algorithms for syphilis serodiagnosis and implications for clinical management. Clin Infect Dis. 2014. 58:1116–24.

4.Marangoni A., Moroni A., Accardo S., Cevenini R. Laboratory diagnosis of syphilis with automated immunoassay. J Clin Lab Anal. 2009. 23:1–6.

5.Young H., Pryde J., Duncan L., Dave J. The Architect Syphilis assay for antibodies to Treponema pallidum: an automated screening assay with high sensitivity in primary syphilis. Sex Transm Infect. 2009. 85:19–23.

6.Kim HS., Lee YK., Kang HJ. Serologic test for syphilis by Mediace RPR test for chemistry autoanalyzer. J Lab Med Qual Assur. 2007. 29:195–9.

7.National Committee for Clinical Laboratory Standards. User verifca-tion of precision and estimation of bias; approved guideline EP15-A3. Wayne, PA: National Committee for Clinical Laboratory Standards. 2014.

8.National Committee for Clinical Laboratory Standards. Evaluation of the llinearity of quantitative measurement procedures: a statistical approach; approved guideline EP6-A. Wayne, PA: National Committee for Clinical Laboratory Standards. 2008.

9.Park HJ. Clinical observation and statistical consideration of syphilis (2000–2007). Korean J Dermatol. 2008. 46:1344–52.

10.Larsen SA., Steiner BM., Rudolph AH. Laboratory diagnosis and interpretation of tests for syphilis. Clin Microbiol Rev. 1995. 8:1–21.

11.Song EY., Yang JS., Chae SL., Kim S., Choi YS., Cha YJ. Current status of external quality assessment of syphilis test in Korea. Korean J Lab Med. 2008. 28:207–13.

12.WiseMeditech. Reagent information of Auto RPR Plus. Mar. 2014.

13.WiseMeditech. Reagent information of Auto TPIM Plus. Jan. 2014.

14.Noh J., Ko HH., Yun Y., Choi YS., Lee SG., Shin S, et al. Evaluation of performance and false positivity of Mediace RPR test that uses a chemistry autoanalyzer. Korean J Lab Med. 2008. 28:312–8.

15.Morshed M., Singh AE. Recent trends in the serologic diagnosis of syphilis. Clin Vaccine Immunol. 2015. 22:137–47.

Fig. 1.

Linearity of Auto RPR Plus test (A) and Auto TPIM Plus test (B).

Fig. 2.

Linear regression of two quantitation RPR tests (A) and Bland-Altman plot of Auto RPR Plus and Mediace (B).

Table 1.

Characteristics of syphilis test reagents

Characteristics	Auto RPR Plus	Auto TPIM Plus	Mediace RPR	Syphilis TP
Company	WiseMeditech	WiseMeditech	Sekisui	Abbott
Instrument		Hitachi 7600		Architect 2000i
Principle	Immunoturbidimetry	Immunoturbidimetry	Immunoturbidimetry	Chemiluminescent microparticle immunoassay
Treponemal or Non-Treponemal	Non-Treponemal	Treponemal	Non-Treponemal	Treponemal
Quantitative or qualitative	Quantitative	Quantitative	Quantitative	Qualitative
S/CO or COI	1.0 U	10 U	1.0 U	S/CO, 1.0
Analytical range	0.1–8.8	2.0–258.5

Abbreviations: RPR, rapid plasma regain; S/CO, signal-to-cutoff ratio; COI, cutoff index; U, Units.

Table 2.

Precision of Auto RPR Plus, Mediace RPR, Auto TPIM Plus and Abbott Syphilis TP

	Within-run precision			Between-run precision
	Mean (U)	SD (U)	CV (%)	Mean (U)	SD (U)	CV (%)
Auto RPR Plus (WiseMeditech)
Negative	0.34	0.04	15.7	0.28	0.23	67.7
Positive	2.52	0.06	2.3	2.62	0.08	3.3
Mediace RPR (Sekisui)
Negative	0.14	0.02	20.4	0.11	0.05	39.1
Positive	2.10	0.05	2.3	2.15	0.07	3.4
Auto TPIM Plus (WiseMeditech)∗
Positive	67.00	1.91	2.7	70.20	2.65	4.0
Abbott Syphilis TP (Abbott)
Negative	0.047	0.004	8.5	0.043	0.003	7.0
Positive	2.609	0.060	2.3	2.533	0.038	1.5

^∗ The levels of negative control were too low to calculate within-run and between-run precisions. Abbreviations: RPR, rapid plasma regain; SD, standard deviation; CV, coefficient of variation.

Table 3.

Precision of Auto RPR Plus, Mediace RPR and Auto TPIM Plus around cutoff values

Assigned		Within-run precision
value (U)		Mean (U)	SD (U)	CV (%)
Auto RPR Plus (WiseMeditech)
Level 1	0.66	0.58	0.11	19.0
Level 2	1.26	1.25	0.09	7.2
Level 3	1.65	1.77	0.13	7.3
Mediace RPR (Sekisui)
Level 1	0.53	0.38	0.08	21.1
Level 2	1.03	0.90	0.11	12.2
Level 3	1.36	1.40	0.20	14.3
Auto TPIM Plus (WiseMeditech)
Level 1	6.27	4.55	1.18	25.9
Level 2	8.96	7.20	1.15	16.0
Level 3	10.45	9.50	1.28	13.5
Level 4	12.54	12.00	0.79	6.6
Level 5	15.68	15.20	0.62	4.1

Abbreviations: RPR, rapid plasma regain; SD, standard deviation; CV, coefficient of variation.

Table 4.

Comparison of results from Auto RPR Plus and Mediace RPR

Mediace RPR	Auto RPR Plus		Total
Mediace RPR	Non-reactive	Reactive	Total
Non-reactive	397	-	397
Reactive	12	22	34
Total	409	22	431

Agreement rate: 97.2% (419/431).

Table 5.

Comparison of results from TPIM Plus and Architect TP

Architect TP	TPIM Plus		Total
Architect TP	Non-reactive	Reactive	Total
Non-reactive	378	7	385
Reactive	-	46	46
Total	378	53	431

Agreement rate: 98.4% (424/431).

Table 6.

Discrepant results between RPR and Treponemal tests

	Auto RPR Plus (U)	Mediace RPR (U)	Auto TPIM Plus (U)	Architect Syphilis TP	FTA-ABS IgM	FTA-ABS IgG
Auto RPR Plus (–)/Mediace RPR (+)	0.4	1.3	3	0.05	N	N
	0.0	5.1	3	0.08	N	N
	0.7	1.7	246	34.49	N	R
	0.3	1.5	214	38.27	N	R
	0.3	1.0	88	24.76	N	R
	0.5	1.0	262	34.48	N	R
	0.6	2.4	36	10.24	NA	NA
	0.7	2.6	38	11.61	N	R
	0.7	2.9	223	25.61	N	R
	0.5	1.7	57	22.73	N	R
	0.5	1.8	306	25.67	N	R
	0.2	1.4	116	22.38	N	R
Auto TPIM PLUS (+)/Architect Syphilis TP (–)	0	0	40	0.43	N	N
	0	0	45	0.04	N	N
	0.1	0	25	0.06	N	N
	0	0	12	0.58	N	N
	0.2	0	11	0.12	N	N
	0	0	65	0.49	N	WR
	0.3	0	10	0.22	N	N

Abbreviations: RPR, rapid plasma regain; U, Units; FTA-ABS, fluorescent treponemal antibody absorption; N, nonreactive; R, reactive; WR, weakly reactive; NA, not assayed.

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