Pb poisoning help

[MDmePwease]

---

Members don't see this ad.

Im trying to wrap my head fully around Pb poisoning and Microcytic anemia. Can someone please explain why you have a low TIBC with Pb poisoning?
The way I understand it is, in Pb poisoning, you release less Fe into the blood stream due to release of Hepcidin. This then lowers the concentration of Fe in the blood and therefore there is less Fe to bind Transferrin which should, at least by my understanding, increase the binding capacity (TIBC). The literature however, claims that TIBC is lowered. For the love of god why?!?!"?!@??! Help is appreciated

 

[oceanillusion42]

Im trying to wrap my head fully around Pb poisoning and Microcytic anemia. Can someone please explain why you have a low TIBC with Pb poisoning?
The way I understand it is, in Pb poisoning, you release less Fe into the blood stream due to release of Hepcidin. This then lowers the concentration of Fe in the blood and therefore there is less Fe to bind Transferrin which should, at least by my understanding, increase the binding capacity (TIBC). The literature however, claims that TIBC is lowered. For the love of god why?!?!"?!@??! Help is appreciated

It isn't that the TIBC is decreased because transferrin is unbound due to low Fe levels in the blood. Rather, the body still has adequate stores of Iron... in fact more than enough... iron stores are INCREASED as is evidenced by increased ferritin levels. This increase in iron stores down-regulates transferrin production leading to low levels of transferrin and thus low TIBC.

 

[blaqmamba]

Fe is leaking out because protoporphryin isn't being made (Pb inhibits Ferrochelatase and dALA dehyrdratase) - this Fe is taken up, and along with the already stored Fe increased Ferritin (what Fe is stored as inside cells)
With increased Ferritin, TIBC (aka Transferrin) is downregulated and decreases

I'm not sure if/how Hepcidin plays into this. But even with your explanation, if Fe is taken up, Ferritin goes UP, which means TIBC would go down.

Note;
I'm pretty sure any time Ferritin goes up, TIBC goes down - unless someone can point to a situation that doesn't happen in

You should also look up exactly what TIBC is/does to better understand the pathophys

 

[blaqmamba]

It isn't that the TIBC is decreased because transferrin is unbound due to low Fe levels in the blood. Rather, the body still has adequate stores of Iron... in fact more than enough... iron stores are INCREASED as is evidenced by increased ferritin levels. This increase in iron stores down-regulates transferrin production leading to low levels of transferrin and thus low TIBC.

Didn't notice it was already answered.

 

[gyrus321]

I think liver regulates this right? If there's increased amount of Fe and ferritin stores, liver senses this and decreases its production of transferrin, thus TIBC decreases. Feel free to correct me.

 

[oceanillusion42]

I think liver regulates this right? If there's increased amount of Fe and ferritin stores, liver senses this and decreases its production of transferrin, thus TIBC decreases. Feel free to correct me.

yup