protein-bound iodine test(redirected from PBI test)
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protein-bound iodine test
a laboratory test done to determine thyroid function by measuring the amount of iodine contained in compounds bound to plasma proteins. It has been largely replaced by radioimmunoassay for the thyroid hormones thyroxine (T4) and triiodothyronine (T3).
pro·tein-bound i·o·dine test
a formerly used test of thyroid function in which serum protein-bound iodine is measured to provide an estimate of hormone bound to protein in peripheral blood.
Synonym(s): PBI test