Talk:Total iron-binding capacity

MerckMedicus: total iron-binding capacity (TIBC)a measure of the total amount of iron that can be bound by the transferrin in a serum sample, determined by saturating the transferrin with iron, then removing the unbound iron with an absorbent and measuring the iron in the filtrate; used in the evaluation of patients with iron deficiency or overload.

Above is the definition for TIBC from Merckmedicus, which is also the definition accepted by multiple other sources I've checked. This article, however, seems to be falsely defining TIBC as the free Fe-binding spots (which would in fact be be the UIBC = unsaturated iron-binding capacity). For example, the article states the following, "Generally speaking, if the iron stores in the body are low, fewer of these spots on the transferrin molecules will be filled by iron, and the TIBC will therefore be higher". This is absolutely untrue for TIBC, though true for UIBC. TIBC is essentially a measurement of the total funtional Transferrin, and does not change unless the active [Apo/Transferrin] is changed. TIBC does not change simply because [Fe] changes. TIBC changes because changes in [Fe] induce increased or decreased production of Apotransferrin.

It is simply an indirect measurement of [Apo/Transferrin].

This is an article that is accessed by many medical students globally, please someone make the appropriate changes quickly. Thank you.

217.162.37.63 (talk) 17:16, 31 December 2008 (UTC)

Agreed. I have removed the misleading statement. It is a common misunderstanding that TIBC measures the amount of iron that can be added to a serum sample in addition to the amount of iron already present (ie, that it measures the number of unbound spots in transferrin). Indeed, the number of sites not carrying iron is reflected by the UIBC, as you correctly state. The 'T' in TIBC does stand for 'total' after all, and it measures the ammount of iron that can be carried by transferrin the sample, period. Weather it is iron that the patient absorbed after breakfast or iron that the technician sprinkled on in the lab in order to make the determination makes no difference. Naturstud (talk) 23:22, 11 January 2009 (UTC)

I would think it would be helpful to show the (seemingly simple) relationship between TIBC, serum iron, UIBC and saturation on the main page. It might help to eliminate some of the confusion over TIBC as well. It helped me a great deal to read the discussion here. — Preceding unsigned comment added by 96.234.145.144 (talk) 13:01, 14 October 2011 (UTC)

TIBC should be indirect measure of transferrin, not transferrin saturation
Sources include First Aid (explained in their 2008 addendum AND further corrected in their 2009 addendum...apparently this is confusing enough of a subject for even Dr. Le et al) and http://www.labtestsonline.org/understanding/analytes/tibc/test.html. Makes sense because % transferrin saturation = serum Fe / TIBC. Besides, the referenced source's title collaborates my claim. I didn't have time to read the entire article but if someone disagrees, please reply to this discussion. Am changing the Wikipedia article. -- Bubbachuck (talk) 19:37, 11 April 2009 (UTC)

So is UIBC an indirect measure of apotransferrin?
The UIBC is calculated by subtracting the serum iron from the TIBC. Transferrin When not bound to iron, it is known as "apotransferrin" — Preceding unsigned comment added by EricStruble (talk • contribs) 03:15, 11 August 2014 (UTC)