HTLV I/II Antibody, with Reflex to Confirmatory Assay

Test Codes

EPIC: LAB1232057, Beaker: XHTLV I/II Ab, Quest: 36175

Department

Send Outs

Instructions

Includes:
If HTLV-I/II Antibody is Reactive, then HTLV-I/II Antibody, Confirmatory Assay will be performed at an additional charge (CPT code(s): 86689).

Specimen Collection Criteria

Collect (preferred specimen): One Gold-top SST tube.

Also acceptable: One plain Red-top tube.

Send specimen for processing immediately after collection.

Physician Office/Draw Specimen Preparation

Let specimen clot 30-60 minutes then centrifuge to separate serum from cells. Transfer serum to plastic transport tube and maintain at refrigerate (2-8°C or 36-46) prior to transport.

Preparation for Courier Transport

Transport: 2.0 mL serum, refrigerated (2-8°C or 36-46). (Minimum: 1.0 mL)

Rejection Criteria

• Grossly hemolyzed specimen
• Grossly lipemic specimen
• Grossly icteric specimen
• Specimens not collected and processed as indicated.

In-Lab Processing

Let specimen clot 30-60 minutes then centrifuge to separate serum from cells. Transfer serum to plastic transport tube and maintain at refrigerate (2-8°C or 36-46).

Transport: 2.0 mL serum, refrigerated (2-8°C or 36-46). (Minimum: 1.0 mL)

Storage

Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): Unacceptable
Refrigerated (2-8°C or 36-46°F): 14 days
Frozen (-20°C/-4°F or below): 30 days

Specimen Storage in Department Prior to Disposal:

Specimen retention time is determined by the policy of the reference laboratory. Contact the Send Outs Laboratory with any questions.

Laboratory

Sent to Quest Diagnostics, Wood Dale, IL.

Performed

Monday – Friday.
Results available in 2-5 days.

Reference Range

Non-reactive.

Test Methodology

Screen: Immunoassay (IA), Confirmation: Immunoblot (IB)

Interpretation

By report.

Clinical Utility

HTLV-I/II Antibody, with Reflex to Confirmatory Assay – This test is intended to aid in the clinical diagnosis of Human T-lymphotropic Virus Type I (HTLV-1) or Type II (HTLV-II) infection. An ELISA is used for the initial detection of antibodies to HTLV-I/II. Specimens with reactive ELISA results reflex to supplemental testing using a line immunoassay (LIA) for confirmation and differentiation of HTLV type.

While the ELISA assay is highly sensitive, specimens containing low titers of antibodies from certain areas of endemicity, or specimens from early sero-converters may be missed. Repeat testing should be considered where there is clinical suspicion of HTLV-I or HTLV-II infection. Nucleic acid amplification test (NAAT) can be used to detect infected individuals either with low antibody titers or within the window period prior to the development of an antibody response. For samples with reactive ELISA and indeterminate resulting using LIA, further investigation should be considered, including repeat testing in 3 months by serology or NAAT.

Disease Reporting

This is a reportable infection, and positive results will be reported to the Oakland County Health Department. For more information on reportable diseases, contact the Epidemiology Department at (248) 551-4040.

Epidemiology

HTLV-1 is primarily endemic in southwestern Japan and the Caribbean, however, parts of sub-Saharan Africa and Central and South America also have significant seroprevalence. Increased seropositivity has been observed in the Southwestern United States, the United Kingdom, and in countries with large Caribbean populations. Approximately 0.1% of males and 0.2% of females infected at childhood develop ATL as adults. HTLV-1 appears to have very little genetic variability. (1)

Incubation Period

10-30 years. Infection is assumed to be lifelong. HTLV-1 associated myelopathy sometimes develops just a few years after infection. (1)

Transmission

HTLV-1 is poorly contagious, and transmission can occur via blood transfusion, contaminated needles, sexual contact, and from mother to child through breast feeding. (1)

Reference

1. Wiedbrauk D, Johnston SLG. Manual of Clinical Virology, Raven Press, New York, NY, 1993.

CPT Codes

86790, (86689 if indicated for confirmation).

Contacts

Last Updated

12/19/2025