Evaluation of the BioPlex 2200 syphilis total screen (IgG/IgM) with reflex to an automated rapid plasma reagin test

• Published in: Journal of clinical laboratory analysis Vol. 33; no. 5; pp. e22878 - n/a
• Main Authors: Rourk, Angela R., Litwin, Christine M.
• Format: Journal Article
• Language: English
• Published: United States John Wiley & Sons, Inc 01-06-2019; John Wiley and Sons Inc
• Subjects: Agglutination; Antibodies, Bacterial - blood; Antibodies, Bacterial - immunology; Automation; Automation, Laboratory; Bacterial infections; False Positive Reactions; Humans; Immunoglobulin G; Immunoglobulin G - blood; Immunoglobulin M; Immunoglobulin M - blood; rapid plasma reagin; Rapid plasma reagin test; Reagin; Reagins - blood; Sensitivity and Specificity; Syphilis; Syphilis - blood; Syphilis - diagnosis; Syphilis Serodiagnosis - methods; TP‐PA; Treponema pallidum; Treponema pallidum - immunology; syphilis; TP-PA; rapid plasma reagin; Treponema pallidum
• ISSN: 0887-8013; 1098-2825
• DOI: 10.1002/jcla.22878

Background
We evaluated the recently FDA cleared BioPlex 2200 Syphilis Total Screen and automated rapid plasma reagin (RPR) assay for the detection of total (IgG/IgM) treponemal and non‐treponemal antibodies in the reverse syphilis algorithm.
Methods
Prospectively submitted samples (n = 885) were assayed by both the IgG/IgM BioPlex Syphilis Screen and the original IgG BioPlex Syphilis Screen. The IgG screen reactive samples were reflexed to traditional RPR, and IgG/IgM screen reactive samples were reflexed to the automated RPR. Nonreactive RPR samples were tested by the Treponemal Pallidum Particle Agglutination test (TP‐PA). Additional samples were collected (n = 404 total samples) to directly compare the automated and traditional RPR assays with each other.
Results
The sensitivity and specificity of the IgG/IgM screen with automated RPR was 95.6% (95% confidence interval [CI] 87.0‐99.1) and 99.6% (CI 99.2‐99.8) while the sensitivity and specificity of the BioPlex IgG screen with traditional RPR was 97.8% (CI 89.1‐99.9) and 99.3% (CI 98.8‐99.4). The sensitivity and specificity of the BioPlex RPR compared with traditional RPR was 95.8% (CI 93.9‐97.0) and 94.1% (CI 89.4‐91.1) and 95.3% (CI 92.6‐97.1). The mean of the titer differences between the BioPlex RPR and the traditional RPR was 1.0 ± 0.9 SD titers.
Conclusion
The addition of the detection of treponemal IgM antibodies to the IgG/IgM screen did not significantly affect the sensitivity and specificity compared to the original IgG screen. However, the addition of the comparable BioPlex RPR assay to the instrumentation significantly reduces the overall labor of syphilis screening and confirmation.