What is the half-life of prelbumin?

• A. 2-3 days
• B. 1 day
• C. 6 hours
• D. 1 week

Answer: (A)

Half-life is the time it takes for the amount of a protein in the blood to fall by half. Prealbumin, also called transthyretin, has a relatively rapid turnover among plasma proteins, with a half-life around two days. This short half-life means it can reflect changes in nutritional status or inflammation over the past few days, unlike albumin which turns over much more slowly (about 20 days). The 2–3 day range best matches this known turnover rate, making it the most accurate choice. The other options—6 hours, 1 day, or 1 week—do not align with prealbumin’s typical turnover timing.