 |
| |
Syphilis / RPR testing
Notification Date: 5/15/2024
Effective Date: 5/16/2024 |
SUBJECT: RPR testing will be performed at St. Mary’s Hospital - Madison
SITES: ST. MARY’S, ST CLARE, JANESVILLE, and MONROE HOSPITALS, and DEAN CLINICS
Bringing RPR testing into St. Mary’s lab will further improve turnaround time for syphilis screening and provide more rapid turnaround time for assessment of congenital syphilis.
To align with the system initiatives and reduce ordering confusion, we have streamlined the orderable syphilis tests as noted below:
- Syphilis Screening: SYPHILIS TOTAL AB SCREEN WITH REFLEX (LAB12272)
- Congenital Syphilis/Syphilis Monitoring: RPR WITH REFLEX TO TITER (LAB12430)
DISCONTINUED: RPR WITH REFLEX TITER AND TP-PA CONFIRMATION (LAB07050) – this traditional Syphilis screening method will be discontinued and no longer orderable.
See below information for more detail on the reverse algorithm screen.
Reverse syphilis testing algorithm starts with an assay to measure IgM and IgG antibodies specific to Treponema pallidum (TP) utilizing the Syphilis TP antibody CMIA assay which will be performed at St. Mary’s Madison.
Advantages of utilizing the Reverse Syphilis Screening Model:
- The TP antibody screening test is specific to syphilis (although false positives may occur).
- TP antibodies are more sensitive than RPR for detecting both primary and late syphilis.
- The TP antibody assay can be performed within the SSM Wisconsin region to improve turnaround time.
Samples which are reactive for TP (syphilis) antibodies will be reflexed to rapid plasma reagin (RPR) confirmation testing to help distinguish between infection with T. pallidum (syphilis) versus a falsely reactive treponemal antibody result.
The TP antibody test and RPR test can identify persons previously treated for syphilis and those with untreated or incompletely treated syphilis.
Discordant results between the syphilis TP antibody assay and RPR will be further reflexed to a second treponemal test, Treponema Pallidum Particle Agglutination (TP-PA) for further evaluation if necessary.
Please see the chart below for interpreting results utilizing the reverse screening model.
Table. Interpretation and follow-up of syphilis reverse screening results
Patient History |
Syphilis (TP) IgM/IgG antibody screen CMIA |
RPR |
TP-PA |
Interpretation |
Follow - up |
| Unknown history of syphilis |
Nonreactive |
N/A |
N/A |
No serologic evidence of syphilis |
None, unless clinically indicated (e.g. early/acute/primary syphilis) |
| Unknown history of syphilis |
Reactive |
Reactive |
N/A |
Untreated or recently treated syphilis |
See Centers for Disease Control and Prevention treatment guidelines |
Unknown history of syphilis |
Reactive |
Nonreactive |
Nonreactive |
Probable false-positive screening test |
No clinical follow-up testing, unless clinically indicated (e.g. acute/primary syphilis) |
Unknown history of syphilis |
Reactive |
Nonreactive |
Reactive |
Possible syphilis (e.g. early or latent) or previously treated syphilis |
Historical and clinical evaluation required |
| Known history of syphilis |
Reactive |
Nonreactive |
Reactive or N/A |
Past, successfully treated syphilis |
None |
CMIA = Chemiluminescent microparticle immunoassay
RPR = rapid plasma reagin
TP-PA = Treponema pallidum particle agglutination
Please communicate to colleagues and staff in your area accordingly.
Please direct questions or comments to:
| Amy Little Soldier |
Molly Gurney, M.D. |
| Laboratory Technical Specialist, Chemistry |
Assistant Laboratory Medical Director, Chemistry |
| SSM Health St. Mary’s Hospital Madison |
SSM Health St. Mary’s Hospital Madison |
| Office: (608) 258-6910 |
Office: (608) 258-6914 |
| amy.littlesoldier@ssmhealth.com |
molly.gurney@ssmhealth.com |
Thank you,
Adam Morgan, M.D.
Laboratory Medical Director
Pathology, SSM Health St. Mary’s Hospital Madison
700 South Park Street
Madison, WI 53715
Office: (608) 258-6914 |
|
