ARUP's Laboratory Test Directory

Treponema pallidum Antibody, IgM by ELISA : 0050921

Mnemonic: SYPH M

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 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: 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 between maternally derived IgG antibodies which cross the placenta, from the IgM antibodies of an active infection in the newborn. In IgM testing for congenital syphilis, the sensitivity is 80%. Therefore, a negative IgM does not necessarily rule out the possibility of congenital syphilis.

Refer to Statement D under Testing Information at http://www.aruplab.com.
CPT Code(s): 86780
Cross References: Syphilis Antibody (Treponema pallidum Antibody, IgM by ELISA)
 
 

 

 

 
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