Thyroid peroxidase antibodies and thyroglobulin antibodies are among the most important markers for identifying autoimmune thyroid disease. They often become elevated years before TSH or thyroid hormones shift, making them critical for early detection and intervention.
But practitioners face a significant challenge: laboratories use vastly different testing methods, units, and reference ranges for these markers. One lab reports TPO antibodies in IU/mL with a reference range of 0-34. Another uses kU/L with a range of 0-9. A third reports only "Positive" or "Negative." These results cannot be compared directly or used in standardized clinical algorithms.
Optimal DX has introduced two new derived biomarkers designed to solve this problem:
The Anti-TPO Index and TgAb Index normalize thyroid antibody results by expressing each value as a multiple of the laboratory's optimal range. An Index of 1.0 means the result is at the optimal boundary. An Index of 2.0 means twice that level.
This approach works because Optimal DX maintains lab-specific reference ranges for over 50 laboratories worldwide. When a blood test is analyzed, the system automatically applies the correct range for that laboratory and calculates the normalized Index.
With these new indices, practitioners can now:
Identify autoimmune thyroid activity before hormonal dysfunction develops. The new Autoimmune Thyroid Activity pattern fires based on antibody elevation alone, independent of TSH or thyroid hormone status. This supports early identification and intervention.
Understand the etiology of thyroid dysfunction. When patterns like Primary Hypothyroidism or Thyroid Conversion Syndrome are elevated, practitioners can now determine whether autoimmune involvement is contributing by cross-referencing the Autoimmune Thyroid Activity score.
Track antibody trends over time. Because the Index normalizes results across laboratories, meaningful comparisons can be made even when patients change labs between tests.
The indices use straightforward thresholds:
Below 1.0 indicates no significant autoimmune activity. Values between 1.0 and 3.0 indicate mild to moderate autoimmune activity. Values above 3.0 indicate significant autoimmune involvement.
The Anti-TPO Index and TgAb Index are now available to all Optimal DX subscribers. They appear automatically when thyroid antibody results are present in the blood test data. Detailed reference guide entries and clinical interpretation guidance are available in the platform's Resource Center.
OPTIMAL DX MEMBERS CLICK HERE to learn more about the new ODX Thyroid Antibody Indices
For more information about Optimal DX and Functional Blood Chemistry Analysis, visit optimaldx.com/pricing.