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Test Code HTLLC Human T-Cell Lymphotropic Virus Types 1 and 2 (HTLV-1/-2) Antibody Confirmation, Spinal Fluid


Ordering Guidance


This confirmatory assay should be ordered only on spinal fluid specimens that are consistently reactive by an antihuman T-cell lymphotropic virus 1 and 2 (HTLV-1/-2) screening immunoassay. For an evaluation that includes both screening and confirmation, order HTLVC / Human T-Cell Lymphotropic Virus Types 1 and 2 (HTLV-1/-2) Antibody Screen with Confirmation, Spinal Fluid.

 

For testing serum specimens, order HTLVL / Human T-Cell Lymphotropic Virus Types I and II (HTLV-I/-II) Antibody Confirmation, Serum.



Necessary Information


Date of collection is required.



Specimen Required


Collection Container/Tube: Sterile vial

Specimen Volume: 0.5 mL


Useful For

Confirmatory detection of human T-cell lymphotropic virus types 1 and 2 (HTLV-1 and HTLV-2)-specific IgG antibodies in spinal fluid specimens that are consistently reactive by initial screening tests

 

Differentiating between HTLV-1- and HTLV-2-specific IgG antibodies present in spinal fluid

Method Name

Line Immunoassay (LIA)

Reporting Name

HTLV -1/-2 Ab Confirmation, CSF

Specimen Type

CSF

Specimen Minimum Volume

0.2 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
CSF Frozen (preferred) 30 days
  Refrigerated  14 days

Reference Values

Negative

Interpretation

Negative confirmatory test results indicate the absence of both human T-cell lymphotropic virus types 1 and 2 (HTLV-1 and HTLV-2)-specific IgG antibodies in spinal fluid and a low probability of an HTLV-1/-2-associated neurologic disorder.

 

A reactive screening (enzyme immunoassay) result with a negative or indeterminate confirmatory (line immunoassay) test result suggests either a false-reactive screening test result or a seroconverting HTLV infection. Repeat testing with a new specimen can clarify the final infection status. Persistently indeterminate confirmatory test results indicate an absence of HTLV infection.

 

Positive results for HTLV-1 antibodies indicate the confirmed presence of HTLV-1 IgG antibodies in spinal fluid, based on 2 visible antibody bands that include gp21-I/-II band, or 3 or more bands, and the sum of the gp46-I and p19-I band intensity is greater than the gp46-II band intensity.

 

Positive results for HTLV-2 antibodies indicate the confirmed presence of HTLV-2 IgG antibodies in spinal fluid, based on 2 visible antibody bands that include gp21-I/-II band, or 3 or more bands, and the gp46-II band intensity is a) greater than the gp46-I band intensity and b) greater than or equal to the sum of the gp46-I and p19-I band intensity.

 

Indeterminate results indicate the presence of the gp21-I/-II band only or combination of any 2 bands without a detectable gp21-I/-II band. Patients with indeterminate test results with known risk factors for HTLV-1 or HTLV-2 infection should undergo repeat confirmatory antibody testing with a new specimen to determine final infection status.

 

Differentiation of HTLV-1 and HTLV-2 infection is not possible (ie, nontypeable HTLV antibodies) when the band intensity pattern does not meet the criteria of positive HTLV-1 or HTLV-2 antibody band intensity pattern.

 

Unreadable results indicate the presence of nonspecific background reactivity that is inhibiting the visualization of specific bands on the test strip. Repeat testing with a new specimen is recommended.

 

Invalid results indicate that nonspecific band reactivity is present. Submit another specimen for retesting if clinically indicated.

Clinical Reference

1. Mahieux R, Gessain A. Adult T-cell leukemia/lymphoma and HTLV-I. Curr Hematol Malig Rep. 2007;2(4):257-264. doi:10.3390/v8060161

2. Yamano Y, Sato T. Clinical pathophysiology of human T-lymphotropic virus-type I-associated myelopathy/tropical spastic paraparesis. Front Microbiol. 2012;3:389. doi:10.3389/fmicb.2012.00389

3. Marrero Rolon RM, Yao JDC. Laboratory diagnosis of HTLV-1-associated myelopathy. Clin Microbiol Newslett. 2020;42(16)129-134. doi:10.1016/j.clinmicnews.2020.07.004

Day(s) Performed

Tuesday

Report Available

2 to 15 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

86689

LOINC Code Information

Test ID Test Order Name Order LOINC Value
HTLLC HTLV -1/-2 Ab Confirmation, CSF 93744-1

 

Result ID Test Result Name Result LOINC Value
604935 HTLV-1/-2 Ab Confirmation, CSF 93745-8
604945 HTLV-1/-2 Bands 93743-3
604946 HTLV-1/-2 Discrimination 93742-5

Forms

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