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@acestep RT. BTW DO U HAVE THE ANS TO Q U POST HERE?
@shool u are correct TIBC as mention DEC
Look at math %transferrin saturation (serum iron/TIBC) TIBC more important eq the more
you have DEC in TIBC the grater % tras sat would be and thats why also “Transferrin saturation best test” does it make scene? hope it does.
Transferrin is the iron transport (Taxi) in the plasma this TAXI has 2 door (binding sites) w Fe3 iron with unbelievable high affinity. We can say; then complete IRON in plasma riding the TAXI- u call the taxi + 2 passenger of iron *holotrnasferrin.
* This amount of transferrin can bind a total of ~ 300 μg of iron (per deciliter of plasma)-> represent as TIBC. Norm taxi is ~ 30% saturated w iron (overload up 45%)
In lab, that is correct the taxi conc -> measure TIBC, and % of high/affinity door that is occupied by iron -> % iron sat.
Hope that make sense & I'm not drunk again.
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shool u are correct thinking in first page bz "Ceruloplasmin than in operation w ferrioxidase activity for convertion of Fe2 -> Fe3 then bound to Taxi. But be honest with u still think the Q asking "Which of the following laboratory values is seen in this "disease"?" take A as ans.
I maybe wrong but hope acestep provide ans.
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as per your nice analogy as far as i understand the situation is like this:
"number of passengers" = serum iron (both seated on taxi and unseated): increased
"free taxi seats": decreased
"number of the taxis"=transferrin: decreased
"total number of free taxi seats"=TIBC : decreased
The Q is that what happens to this ratio: Passenger/total number of free taxi seats?
I would still say increased.
lets see what acestep says. please post the answer if you have it.
Anyway ended up being a nice review of hemochromatosis lab which is a high yield topic.
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@cardio answer is exactly as yours AAA, thank you very much, what i understand is the decrease in TIBC is much more than the increase in serum iron, so more arrows down to TIBC verus one arrow up to serum iron because body try decrease serum iron(downregulation), hence decrease ratio, am I right although i am not convinced because FA says the ratio increased?? so FA is wrong??
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@acestep thank you for Q & welcome pal.
@shool, just remember the TAXI is a Ferrari 458 spider (2 seat car/ "2 binding site")
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Thank you acestep and cardio for the question and discussion.
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normal>>serum iron 100 tibc 300 ratio=1/3
HC >>>>serum iron 200 tibc 200 ratio =1/1
does that mean decreased ratio???
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A
If I may explain my answer this way ,
1) Diag is Hemochromatosis
2) High serum Iron
3) if high serum iron , than we will find low TIBC
the best single test for hemochromatosis is Transferin saturation which is calculated by Serum Iron/ TIBC
is denominator decrease the ration will be increase
Until that point I agree with School, centralherniation etc...
Now I am thinking ....
But apparently there is many etiology of hemochromatosis , THANKS for the question, it took me to a good review to really understand the pathology . In certain hemochromatosis there is a abnormality in the gene that regulate iron . Differently than other hemochromatosis the increased in absorption of iron in the gut is abnormal because the IRP gene expression .
The IRP gene expression is feedback response to decrease intracellular iron concentration which increase ferritin when Iron availability is low .
that brought me to understand in this type of Hemochromatosis intracellular concentration of iron is low and then TIBC is high Ratio SI/TIBC will be low
Just thinking........
Serum iron is calculated for the quantity of iron attached to transferrin , but it is not an estimated of the quantity of iron stored in Ferritin. In this pathology I believe most of the iron is stored in ferritin not in transferrin .
Again I was just thinking.......
