CPT® Code 86794

Official Description

Antibody; Zika virus, IgM

Common Language Description

The CPT® Code 86794 refers to the serologic testing for Zika virus-specific IgM antibodies. This testing is crucial for diagnosing Zika virus infections, particularly in individuals who exhibit symptoms. The serologic test is typically performed starting at the end of the first week of illness, as this is when the body usually begins to produce detectable levels of IgM antibodies against the Zika virus. The specific test utilized for this purpose is the Zika IgM Antibody Capture Enzyme-Linked Immunosorbent Assay (Zika MAC-ELISA). This assay involves a series of steps where the patient's serum is mixed with a known, noninfectious viral antigen, and the presence of antibodies is detected through a colorimetric reaction facilitated by an enzyme-conjugated anti-viral antibody. The results are quantified using a spectrophotometer, which measures the intensity of the color change. However, interpreting the results can be challenging due to the potential for cross-reactivity with antibodies from other viruses and the occurrence of nonspecific reactions. To enhance diagnostic accuracy, IgM serology testing is often conducted alongside DNA or RNA testing, especially in symptomatic pregnant women. In cases where results are equivocal, presumed, or inconclusive, it is essential to forward these to designated CDC laboratories that specialize in plaque-reduction neutralization testing (PRNT) for further confirmation.

1. Indications

The serologic testing for Zika virus-specific IgM antibodies is indicated for the following conditions:

Symptomatic Individuals: Testing is performed on individuals exhibiting symptoms consistent with Zika virus infection, particularly during the acute phase of the illness.
Pregnant Women: Symptomatic pregnant women are a key population for testing due to the potential risks associated with Zika virus infection during pregnancy.
Exposure History: Individuals with a known exposure to Zika virus, especially in endemic areas, may also be tested to confirm or rule out infection.

2. Procedure

The procedure for conducting the Zika IgM Antibody Capture Enzyme-Linked Immunosorbent Assay (Zika MAC-ELISA) involves several detailed steps:

Step 1: The process begins with the collection of the patient's blood serum or cerebrospinal fluid, which serves as the sample for testing.
Step 2: The collected serum is then added to multiple well plates that have been pre-coated with an anti-IgM capture antibody. This step is crucial as it allows for the specific binding of Zika virus IgM antibodies present in the sample.
Step 3: Following the addition of the serum, a known, noninfectious viral antigen is introduced to the wells. This antigen is essential for the detection of any Zika virus-specific antibodies that may be present.
Step 4: After allowing sufficient time for the antibodies to bind to the antigen, an enzyme-conjugated anti-viral antibody is added. This enzyme will react with the bound antibodies, facilitating the detection process.
Step 5: A chromogenic substrate is then introduced, which reacts with the enzyme to produce a color change. The intensity of this color change is directly proportional to the amount of Zika virus IgM antibodies present in the sample.
Step 6: Finally, the colorimetric result is read using a spectrophotometer (ELISA reader), which quantifies the results and provides a measurement of the antibody levels.

3. Post-Procedure

After the Zika IgM antibody testing is completed, it is important to interpret the results carefully due to the potential for cross-reactivity with other viruses. In cases where the results are equivocal, presumed, or inconclusive, it is necessary to forward these results to specific CDC laboratories that are proficient in plaque-reduction neutralization testing (PRNT) for confirmation. Additionally, healthcare providers should consider the clinical context and may recommend further testing, such as DNA or RNA testing, particularly for symptomatic pregnant women, to ensure accurate diagnosis and appropriate management of the patient's condition.

Short Descr	ZIKA VIRUS IGM ANTIBODY
Medium Descr	ZIKA VIRUS IGM ANTIBODY
Long Descr	Antibody; Zika virus, IgM
Status Code	Statutory Exclusion (from MPFS, may be paid under other methodologies)
Global Days	XXX - Global Concept Does Not Apply
PC/TC Indicator (26, TC)	9 - Not Applicable
Multiple Procedures (51)	9 - Concept does not apply.
Bilateral Surgery (50)	9 - Concept does not apply.
Physician Supervisions	09 - Concept does not apply.
Assistant Surgeon (80, 82)	9 - Concept does not apply.
Co-Surgeons (62)	9 - Concept does not apply.
Team Surgery (66)	9 - Concept does not apply.
Diagnostic Imaging Family	99 - Concept Does Not Apply
CLIA Waived (QW)	No
APC Status Indicator	Conditionally packaged laboratory tests
Type of Service (TOS)	5 - Diagnostic Laboratory
Berenson-Eggers TOS (BETOS)	none
MUE	1

90	Reference (outside) laboratory: when laboratory procedures are performed by a party other than the treating or reporting physician or other qualified health care professional, the procedure may be identified by adding modifier 90 to the usual procedure number.
GA	Waiver of liability statement issued as required by payer policy, individual case