TPO
Meaning of TPO: TPO most often names thrombopoietin, the hormone driving platelet production, though the same abbreviation also names an unrelated thyroid enzyme.
Definition of TPO
TPO most commonly identifies thrombopoietin, a hormone produced mainly by the liver that stimulates the bone marrow to produce platelets, the small cell fragments essential for normal blood clotting. Thrombopoietin acts on megakaryocytes, the large bone marrow cells that break apart to release platelets into the bloodstream, encouraging both their growth and their platelet output.
Because thrombopoietin is a naturally occurring hormone, its role in the body is well established, and a separate class of medications, called thrombopoietin receptor agonists, has been developed to mimic thrombopoietin's effect and is used to increase platelet counts in certain conditions involving low platelets.
The same abbreviation, TPO, is also widely used in an entirely different context to refer to thyroid peroxidase, an enzyme involved in producing thyroid hormone, and antibodies against thyroid peroxidase are commonly tested for when evaluating autoimmune thyroid conditions, so the intended meaning of TPO depends heavily on context.
Also known as
Used in a sentence
Thrombopoietin receptor agonist therapy was considered for the patient's persistently low platelet count.
Good to know
The abbreviation TPO refers to two unrelated substances, thrombopoietin, which affects platelet production, and thyroid peroxidase, an enzyme tested for in autoimmune thyroid disease, so context always determines which is meant.