Pathology/Lab Coding Alert

Don’t miss new quantitative test.

With the latest CPT^® code for SARS-CoV-2 antibody testing fresh off the presses in September, lab coders need to understand how to use new antibody codes in the expanding universe of COVID-19 testing.

Let us triage the situation with the following breakdown of CPT^® antibody codes and a primer on key terminology and concepts related to the testing.

Terminology: SARS-CoV-2 is the abbreviation for severe acute respiratory syndrome coronavirus 2, which is the virus that causes the coronavirus disease first identified in 2019 (COVID-19). Antibody tests are sometimes called “serologic tests.”

Say Hello to 86413

In a move to expedite accurate reporting of SARS-CoV-2 testing during the pandemic, the CPT^® Editorial Panel published the following new code on September 8, making it effective immediately: 86413 (Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (Coronavirus disease [COVID-19]) antibody, quantitative).

You now have 86413 in addition to the following two codes to report an antibody test for SARS-CoV-2:

• 86769 (Antibody; severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (Coronavirus disease [COVID-19]))
• 86328 (Immunoassay for infectious agent antibody(ies), qualitative or semiquantitative, single step method (eg, reagent strip); severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (Coronavirus disease [COVID-19]))

Quantitative: The most important distinction between new code 86413 and the two existing codes is that 86413 describes a quantitative assay that measures the level of antibodies in the patient specimen. In contrast, codes 86769 and 86328 report a qualitative or semi-quantitative finding for the presence of antibodies.

“Being able to measure a patient’s relative level of antibodies in response to a previous SARS-CoV-2 infection may be useful as we continue to learn more about the virus and what the existence of antibodies may mean,” says Tim Stenzel, MD, PhD, director of the Office of In Vitro Diagnostics and Radiological Health in the FDA’s Center for Devices and Radiological Health in a press release.

A quantitative test provides valuable information that a qualitative test can’t — for patient care, as well as for increasing understanding of the disease process, and possibly for contributing to treatment regimens. Because the level of different antibody classes, such as IgG and IgM, change over time, having a quantitative measure will help clinicians and scientists understand the SARS-CoV-2 adaptive immune response, contributing to the knowledge base for how the disease progresses. This information can then impact understanding of epidemiology, prevention, and treatment related to COVID-19.

Distinguish 86769 and 86328: “These two codes describe serologic SARS-CoV-2 antibody tests that you can distinguish based on the complexity of the lab method,” explains William Dettwyler, MT-AMT, president of Codus Medicus, a laboratory coding consulting firm in Salem, Ore.

According to CPT^® instruction, immunology tests in the code range 86602-86804 for infectious agent antibody detection “are qualitative or semiquantitative immunoassays performed by multiple-step methods for the detection of antibodies to infectious agents.”

“The distinguishing characteristic for 86769 is that the test is a ‘multiple step method,’ rather than a ‘single-step method’ described by 86328,” Dettwyler says.

Add Codes for Neutralizing Antibodies

In a separate CPT^® announcement, the AMA added the following two new codes for SARS-CoV-2 neutralizing antibody tests, effective August 10:

• 86408 (Neutralizing antibody, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (Coronavirus disease [COVID-19]); screen)
• 86409 (... titer)

“These tests determine if antibodies present in a patient specimen can directly block infection of cells expressing the viral entry receptor on their surface,” according to CPT^® Assistant Special August Edition.

Code 86408 describes a test that screens for the presence of neutralizing antibody(ies) to SARS-C0V-2, reported as a qualitative finding. Code 86409 describes a titer test to measure the level of SARS-C0V-2 antibody-neutralizing activity, reported as a quantitative or semi-quantitative result. The tests commonly evaluate antibodies to the SARS-C0V-2 spike protein involved in binding to a human cell receptor.

Value: Codes 86408 and 86409 assays add to existing SARS-Co-V-2 test options by providing the first way to assess whether patients have produced neutralizing antibodies that can fight off re-infection with the virus.

“The neutralizing antibody test … provides us with incredibly important information about how effective a person’s antibodies are at neutralizing the virus,” says William Morice, II, MD, PhD, president of Mayo Clinic Laboratories in a news release. “This will help us identify optimal convalescent plasma donors and ultimately help assess the efficacy of anti-SARS-CoV-2 vaccines.”

Compare: In contrast, existing tests can determine if a patient is currently infected with the SARS-CoV-2 virus (nucleic acid or immunoassay tests for virus antigens), or if a patient has had a past infection with the SARS-CoV-2 virus (antibody tests).

Valid tests: Note that the FDA requires commercially marketed serologic tests to have Emergency Use Authorization (EUA) for use during the public health emergency. You can access a current list of these tests at www.fda.gov/medical-devices/coronavirus-disease-2019-covid-19-emergency-use-authorizations-medical-devices/eua-authorized-serology-test-performance.You can also find CDC guidance for how to use these tests at www.cdc.gov/coronavirus/2019-ncov/lab/resources/antibody-tests-guidelines.html.