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Test Code Billings Clinic: 8740 Mayo: TRCHG ToRCH Profile IgG, Serum

Reporting Name

Torch Profile IgG, S

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Useful For

Determining immune status of individuals to the rubella virus following vaccination or prior exposure

 

Indicating past or recent infection with Toxoplasma gondii, cytomegalovirus, or herpes simplex virus (HSV)

 

Distinguishing between infection caused by HSV types 1 and 2, especially in patients with subclinical or unrecognized HSV infection

Method Name

Multiplex Flow Immunoassay (MFI)


Ordering Guidance


To evaluate recent or acute infection with Toxoplasma gondii, order TXM / Toxoplasma gondii Antibody, IgM, Serum.

 

For patients presenting with presumed acute infection with herpes simplex virus, order HERPB / Herpes Simplex Virus 1 and 2, Qualitative PCR, Blood.

 

IgG antibodies in patients younger than 6 months of age are typically the result of passive transfer from the mother. To assess possible infection in patients younger than 6 months, consider ordering IgM testing.



Specimen Required


Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 2 mL

Collection Instructions: Centrifuge and aliquot serum into plastic vial.


Specimen Type

Serum

Specimen Minimum Volume

1.2 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 14 days
  Frozen  14 days

Reject Due To

Gross hemolysis Reject
Gross lipemia Reject
Gross icterus Reject
Heat-inactivated specimen Reject

Reference Values

Toxoplasma ANTIBODY, IgG

Negative

 

Toxoplasma IgG

≤9 IU/mL (Negative)

10-11 IU/mL (Equivocal)

≥12 IU/mL (Positive)

 

RUBELLA ANTIBODY, IgG

Vaccinated: Positive (≥1.0 AI)

Unvaccinated: Negative (≤0.7 AI)

 

CYTOMEGALOVIRUS

Negative

 

HERPES SIMPLEX VIRUS (HSV), TYPE 1 AND TYPE 2 ANTIBODIES, IgG

Herpes Simplex Virus (HSV) Type 1, IgG

Negative

 

Herpes Simplex Virus (HSV) Type 2, IgG

Negative

Interpretation

Toxoplasma gondii:

A positive Toxoplasma IgG result is indicative of current or past infection with T gondii. A single positive Toxoplasma IgG result should not be used to diagnose recent infection.

 

Equivocal Toxoplasma IgG results may be due to very low levels of circulating IgG during the acute stage of infection. A second specimen should be submitted for testing if clinically indicated.

 

Individuals with negative Toxoplasma IgG results are presumed to not have had previous exposure to T gondii. However, negative results may be seen in cases of remote exposure with subsequent loss of detectable antibody. Seroconversion from negative to positive IgG is indicative of T gondii infection subsequent to the first negative specimen.

 

Rubella:

Positive: The presence of detectable IgG-class antibodies to rubella indicates prior exposure through infection or immunization. Individuals testing positive for IgG-class antibodies to rubella are considered immune.

 

Equivocal: Submit an additional specimen for testing in 10 to 14 days to demonstrate IgG seroconversion if recently vaccinated or if otherwise clinically indicated.

 

Negative: The absence of detectable IgG-class antibodies to rubella suggests no prior exposure to this virus or the lack of a specific immune response to immunization.

 

Cytomegalovirus:

Positive cytomegalovirus (CMV) IgG results indicate past or recent CMV infection. These individuals may transmit CMV to susceptible individuals through blood and tissue products.

 

Equivocal CMV IgG results may occur during acute infection or may be due to nonspecific binding reactions. Submit an additional specimen for testing if clinically indicated.

 

Individuals with negative CMV IgG results are presumed to not have had prior exposure or infection with CMV and are therefore considered susceptible to primary infection.

 

Herpes Simplex Virus:

The presence of IgG-class antibodies to herpes simplex virus (HSV) types 1 or 2 indicates previous exposure and does not necessarily indicate that HSV is the causative agent of an acute illness.

Day(s) Performed

Monday through Saturday

Report Available

Same day/1 to 3 days

Test Classification

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information

86644-CMV

86695-Herpes simplex, type 1

86696-Herpes simplex, type 2

86762-Rubella

86777-Toxoplasma

LOINC Code Information

Test ID Test Order Name Order LOINC Value
TRCHG Torch Profile IgG, S 102088-2

 

Result ID Test Result Name Result LOINC Value
HS1G HSV Type 1 Ab, IgG, S 51916-5
HS2G HSV Type 2 Ab, IgG, S 43180-9
RBG Rubella Ab, IgG, S 40667-8
CMVG Cytomegalovirus Ab, IgG, S 13949-3
TOXG Toxoplasma Ab, IgG, S 40677-7
DEXG6 Toxoplasma IgG Value 8039-0
DEXG2 Rubella IgG Antibody Index 5334-8

Forms

If not ordering electronically, complete, print, and send Infectious Disease Serology Test Request (T916) with the specimen.

Profile Information

Test ID Reporting Name Available Separately Always Performed
TOXGP Toxoplasma Ab, IgG, S Yes Yes
RBPG Rubella Ab, IgG, S Yes Yes
CMVG Cytomegalovirus Ab, IgG, S Yes Yes
HS1G HSV Type 1 Ab, IgG, S No Yes
HS2G HSV Type 2 Ab, IgG, S No Yes