{"id":"tpo-antibodies","name":"Thyroid Peroxidase Antibodies (TPO)","shortName":"TPO Ab","aliases":["Anti-TPO","TPOAb","Thyroid Peroxidase Antibody","TPO Antibodies","TPO Ab","Thyroperoxidase Ab","Thyroid Peroxidase (TPO) Ab","Thyroid Peroxidase (TPO) Antibodies","Thyroid Peroxidase Antibodies","Anti-Thyroid Peroxidase Antibody","Anti-TPO Antibody","Anti-TPO Ab","TPO Antibody","Antimicrosomal Antibody","Antimicrosomal antibodies","Anti-Microsomal Antibody"],"abbreviations":["TPOAb","TPO Ab","Anti-TPO"],"loinc":[{"code":"8099-4","primary":true},{"code":"56477-3","primary":false},{"code":"32042-4","primary":false},{"code":"5383-5","primary":false}],"specimen":"serum-or-plasma","units":[{"ucum":"[IU]/mL","display":"IU/mL"},{"ucum":"k[IU]/L","display":"kIU/L"}],"referenceRanges":[{"population":"20+","low":0,"high":34,"unit":"[IU]/mL","unitDisplay":"IU/mL","note":"Labcorp cutoff for adults over 19 (Roche cobas immunoassay). Cutoffs are assay-specific, and other labs use different ones (ARUP, on a different chemiluminescent immunoassay, uses 0 to 9.0 IU/mL), so this is a cutoff for a positive result on that method rather than a general range. Use the cutoff and flag printed on your own report. In a US government survey of people without known thyroid disease, 11.3% had positive TPO antibodies, more often in women and in older people.","sources":[{"title":"Thyroid Peroxidase (TPO) Antibodies (test 006676)","url":"https://www.labcorp.com/tests/006676/thyroid-peroxidase-tpo-antibodies","publisher":"Labcorp"},{"title":"Thyroid Peroxidase (TPO) Antibody (test 0050075)","url":"https://ltd.aruplab.com/Tests/Pub/0050075","publisher":"ARUP Laboratories"},{"title":"Serum TSH, T4, and thyroid antibodies in the United States population (1988 to 1994): NHANES III","url":"https://pubmed.ncbi.nlm.nih.gov/11836274/","publisher":"Journal of Clinical Endocrinology & Metabolism","year":2002}]}],"review":{"status":"ai-verified","label":"AI-verified against cited sources. Awaiting expert review","lastReviewed":"2026-10-03"},"summary":"Antibodies aimed at an enzyme in the thyroid. They are linked to autoimmune thyroid conditions such as Hashimoto's thyroiditis.","url":"https://bloodtesttracker.com/markers/tpo-antibodies","notice":"Information, not medical advice. Ranges differ between labs, so the range on your own report is the one your result is judged against."}