ARUP's Laboratory Test Directory

Treponema pallidum Antibody, IgG by ELISA : 0050920

Mnemonic: SYPH G

Ordering Recommendation: Recommended syphilis screening test in so-called reverse screening algorithm. The CDC recommends a nontreponemal test (RPR or VDRL) for initial syphilis screening prior to confirmation with a treponemal test (eg, TP-PA).
Methodology: Semi-Quantitative Enzyme-Linked Immunosorbent Assay
Performed: Wed
Reported: 1-8 days
Specimen Required: Collect: 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: Refrigerated.

Unacceptable Conditions: Plasma or other body fluids. Contaminated, hemolyzed, or severely lipemic specimens.

Stability (collection to initiation of testing): 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 IgG antibody detected.
0.9-1.1 IV: Equivocal - Questionable presence of Treponema pallidum IgG antibody detected.  Repeat testing in 10-14 days may be helpful.
1.2 IV or greater: Positive - Presence of IgG antibody to Treponema pallidum detected, suggestive of current or past infection.
Interpretive Data: 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. The Treponema pallidum Antibody (FTA-ABS), Serum, IgG by IFA (0050477) is recommended for follow-up of reactive nontreponemal tests for syphilis, and as a single test in patients suspected of late syphilis.  For CSF specimens, the Treponema pallidum (VDRL) Cerebrospinal Fluid with Reflex to Titer (0050206) test is recommended.
CPT Code(s): 86780
Cross References: Syphilis Antibody, IgG by ELISA