Treponema pallidum Antibody, IgM by ELISA (Inactive as of 01/05/2015 - no referral available)
Ordering Recommendation
Semi-Quantitative Enzyme-Linked Immunosorbent Assay
1-8 days
New York DOH Approval Status
This test is New York DOH approved.
Submit With Order
ARUP Consult®
Disease Topics
Specimen Required
Patient Preparation
Serum separator tube. 
Specimen Preparation
Separate serum from cells ASAP or within 2 hours of collection. Transfer 1 mL serum to an ARUP Standard Transport Tube. (Min: 0.05 mL) 
Storage/Transport Temperature
Unacceptable Conditions
Plasma or other body fluids. Contaminated, hemolyzed, or severely lipemic specimens. 
After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles) 
Reference Interval
0.8 IV or less: Negative - No significant level of Treponema pallidum IgM antibody detected.
0.9-1.1 IV: Equivocal - Questionable presence of Treponema pallidum IgM antibody detected.  Repeat testing 10-14 days may be helpful.
1.2 IV or greater: Positive - Presence of IgM antibody to Treponema pallidum detected, suggestive of current or recent infection.
Interpretive Data
The CDC recommends initial syphilis screening using a non-treponemal test, such as RPR, prior to confirmation with a treponemal method such as this ELISA or TP-PA.

Seroconversion between acute and convalescent sera is considered strong evidence of recent infection. The best evidence for infection is a significant change on two appropriately timed specimens, where both tests are performed in the same laboratory at the same time. IgM testing is a useful diagnostic aid in differentiating maternally derived IgG antibodies that cross the placenta from IgM antibodies of an active infection in the newborn. Sensitivity in IgM testing for congenital syphilis is 80 percent, therefore, a negative IgM does not necessarily rule out the possibility of congenital syphilis.

CPT Code(s)
Component Test Code*Component Chart NameLOINC
0050921T.Pallidum Antibody, IgM by ELISA51839-9
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
  • Syphilis Antibody
  • Syphilis IgM ELISA
  • T pallidum IgM by ELISA