Syphilis IgM, Blood

Diagnostic Use

For use in monitoring congenital syphilis babies only

Department

Microbiology - Serology

Delphic Registration Code

SIGM

Laboratory Handling

Laboratory

Serology

Constituent Tests

• Syphilis serology – RPR, Blood

Turnaround Time

3 days

Test Code

6070

Specimen Type

• Serum

Specimen Requirements

Tube/Container Type:

Preferred

• Serum (Red Cap)

Preferred if West Coast

• Serum (Red Cap)

Acceptable

• SST II (Gold Cap)

Preferred Sample Volume (ml)

10

Minimum Sample Volume (ml)

2

No of Samples Required

1

Paediatric Specimen Requirements

Tube/Container Type:

Preferred

• Serum (Red Cap)

Acceptable

• SST II (Gold Cap)

Preferred Sample Volume (ml)

2.0

Minimum Sample Volume (ml)

1.0

Aliquot Instructions

Sample Type

• Serum

Minimum Volume (ml)

0.2

Transport to Lab

Ambient (8 - 24 degrees Celsius)
If overnight - Chilled (2 - 8 degrees Celsius)

Interpretation

Following an initial infection, immunoglobulin (Ig)M antibodies are the first class of antibodies produced. Early detection of IgM could therefore help with the diagnosis of early syphilis.  IgM testing is useful in the assessment of newborns but needs to be interpreted not in isolation but in conjunction with other testing, full evaluation and clinical consultation. It should also be noted that a negative IgM result cannot exclude the diagnosis of congenital syphilis.

 

Results should be interpreted in conjunction with other tests and clinical evidence.   Please see additional information section below.

Syphilis is a Notifiable Disease

Reference Intervals

Reported as: Negative, Equivocal, or Positive

 

 

Test Method

EIA

Non-Funded Test Cost

$370.32 (Exclusive of GST)

Billing Code

6070

Neonatal testing for suspected congenital syphilis:

The interpretation of syphilis in neonates requires specialist input as no single test can be used to diagnose congenital syphilis. Passive transfer of maternal antibodies makes interpretation of neonate serology more complex. Specifically, conducting treponemal tests such as TPHA/TPPA and/or SEIA/CLIA screen testing on neonatal serum is not recommended as passively transferred maternal antibodies can persist for >15 months.

When taking samples for testing, paired Maternal serum is required at the same time as paired tests are run comparatively in the same runs and reagents. Send a neonatal venous blood sample (not umbilical cord sample) for syphilis serology (RPR nontreponemal and Treponemal IgM antibody) together with Maternal venous blood for RPR at the time of delivery (if no result recently available at the same testing lab from the previous 4 weeks). Refer to link below to NZSHS website "Syphilis in Pregnancy-Antenatal Management Guidelines for maternal and congenital syphilis."
www.nzshs.org/guidelines

Do not send umbilical cord blood as this can become contaminated with Maternal blood and yield false-positive results, and Wharton's jelly within the umbilical cord can yield a false-negative result.

Test Availability - By arrangement with Virology/Serology

Contact Information

Enquiry Form