Effective Tuesday, April 3, 2018, the University of Iowa Hospitals and Clinics (UIHC) core clinical chemistry laboratory will begin running the Roche Diagnostics automated Syphilis Total Antibodies immunoassay test and the Bio-Rad Rapid Plasmin Reagin (RPR) test.  Syphilis Total Antibodies captures both IgG and IgM antibodies, potentially allowing for earlier diagnosis of primary acute syphilis compared to the previous syphilis IgG testing.

Details on the new set of syphilis tests are as follows:

Test name	Epic #	Specimen	Turnaround time After Receipt in Laboratory
Syphilis Total Antibodies with Reflex Confirmation	LAB8631	Plasma separator tube	2 hrs
Syphilis Treatment Follow-up (RPR with Titer)	LAB8648	Plasma separator tube	1 day*
Rapid Plasma Reagin (RPR) with Reflex Confirmation	LAB8647	Plasma separator tube	1 day* 3-5 days for TP-PA

*Note that RPR titers higher than 1:2048 require send out to reference laboratory.

 

Syphilis Total Antibodies with Reflex Confirmation uses the ‘reverse algorithm’ in place at UIHC since 2013.  Rapid Plasma Reagin (RPR) with Reflex Confirmation uses the older ‘traditional algorithm’ which is no longer the preferred testing method for most populations but is preferred for syphilis testing of infants.

The table below details the possible reflex testing.

Test name	Initial Testing	Reflex Testing
Syphilis Total Antibodies with Reflex Confirmation	Syphilis total antibodies	‘Reverse algorithm’ If screen positive, then RPR If RPR non-reactive, then TP-PA
Syphilis Treatment Follow-up (RPR with Titer)	RPR screen	If screen positive, RPR titer
Rapid Plasma Reagin (RPR) with Reflex Confirmation	RPR screen	‘Traditional algorithm’ If screen positive, RPR titer and then TP-PA

Questions should be directed to Matthew Krasowski, MD, PhD, medical director of the Clinical Chemistry Laboratory (384-9380, matthew-krasowski@uiowa.edu).