Anti-Th/To Ab (RDL)

CPT: 83516
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Test Includes

This test is a component of Scleroderma Comprehensive Profile, Scleroderma Comprehensive Profile Plus, MyoMarker, Myositis.

Expected Turnaround Time

14 - 21 days

Related Documents

Specimen Requirements




1 mL

Minimum Volume

0.3 mL (Note: This volume does not allow for repeat testing.)


Red-top tube or gel-barrier tube


Separate serum from cells within one hour of collection. Transfer to a plastic transport tube before shipping. To avoid delays in turnaround time when requesting multiple tests on frozen samples, please submit separate frozen specimens for each test requested.

Storage Instructions

Refrigerate or freeze.

Stability Requirements



Room temperature

7 days


14 days


60 days

Freeze/thaw cycles

Stable x1

Causes for Rejection

Grossly hemolyzed; bacterial contamination; lipemic specimen; icteric specimen; non-serum specimen types

Test Details


The Th/To antibodies are present in 10-19% of patients with limited SSc, in 11% of patients with diffuse cutaneous SSc, and in 3% of patients with primary Raynaud's disease. Anti-Th/To antibody has been shown to be highly specific for patients with SSc.


This test was developed and its performance characteristics determined by LabCorp. It has not been cleared or approved by the Food and Drug Administration.


RIPA gel radiography

Reference Interval



Order Code Order Code Name Order Loinc Result Code Result Code Name UofM Result LOINC
520016 Anti-Th/To Ab (RDL) 81742-9 520038 Anti-Th/To Ab (RDL) 81743-7

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