Discussion Forums > Thalassemia Major

Fetal Hemoglobin

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Andy Battaglia:
Manal,

Actually the body can survive quite well using fetal hemoglobin just as you could make that bread from rye flour if you have enough rye flour. The purpose of the hydroxyurea is to stimulate the production of more fetal hemoglobin than what is normally present. Surprisingly, the increase in total Hb doesn't have to be a lot before positive results are shown. In Intermedias, as little as a one half point increase in Hb can result in freedom from transfusing.

So just as you can substitute another type of flour to make bread, you can substitute fetal hemoglobin for adult hemoglobin, and as long as you have enough flour or hemoglobin, you'll be ok.

One thing about this topic that I would like to clarify. The percentage of fetal hemoglobin present is not useful in determining the total volume of hemoglobin present. The reason it is mentioned is because fetal hemoglobin is one of the indicators of thalassemia and the higher the percentage of total hemoglobin that is HbF, the more likely the patient has thalassemia. 

§ãJ¡Ð ساجد:
Hi all,

Percentage is a relative quantity. Meaning that it depends on the part of a thing with respect to the whole stuff.

For example:

Your child has HB 6g/dl of TOTAL Haemoglobin; which everyone knows is not sufficient. Out of which 1g is HbA and 5g is HbF. => (1HbA+5HbF=6HB)
This means your child has:
1/6 X 100 = 16.66% of HbA
5/6 X 100 = 83.33% of HbF

Now, although 83% seems a big number, but 83% of total 6g, which is 5g is still not sufficient for survival.

I hope I got this straight ???

Take care, Peace!

Manal:
Thanks Andy a lot , it is more clear now

Thanks Sajid, but the last time i did HPLC for my son was in last July and the percentages were as follows:

81.5% HB A1
6.9% HB A2
11.6% HB F

so what do you think?

Manal

mustho:
Hi Manal

In human being different stages of life there are different types of hemoglobin namely embryonic, fetal and adult hemoglobin. These switching of hemoglobin take place at different timing of life from embryo to adult.

How ever in certain cases such as Thalassemia due to mutations in globin chains there is imbalance in proper hemoglobin formation. For example in Beta Thalassemia major there may be no beta globin formation or less beta globin formation. That may lead to decrease in adult hemoglobin (alpha2 and beta2). Since there is mutation in beta globin formation gamma globin which has to be switch off by nature which is responsible for fetal hemoglobin formation remain in these patients (alpha 2 gamma2).

The question is what’s wrong with high fetal hemoglobin? The role of hemoglobin in the body is to carry oxygen and to deliver the tissues where it is need to produce energy to perform. Fetal hemoglobin has very high affinity for oxygen, but by nature it is not that good to deliver the oxygen to the tissues. Since there is imbalance in globin chains these cells tend to hemolyse quickly and that leads to severe anemia in these patients and they need regular transfusions.

But in Sickle cell anemia and thalassemia intermediate by giving hydroxyuria fetal hemoglobin is increased because both of this condition it helps to carry oxygen. Especially in sickle cell anemia, sickling is more when cells are in hypoxic condition. By having high fetal hemoglobin helps to increase oxygen level in these conditions.

Your question about HPLC results, High Performance Liquid Chromatography is technique to quantitate hemoglobin. Usually very little amount of dilute hemoglobin is fed in to this machine and the results are given as per retention time and these percentages are given. This is totally different from total hemoglobin levels we refer to estimate anemia.

I hope you got some idea about how hemoglobin works.

§ãJ¡Ð ساجد:

--- Quote from: Manal on January 06, 2007, 02:07:13 PM ---Thanks Sajid, but the last time i did HPLC for my son was in last July and the percentages were as follows:

81.5% HB A1
6.9% HB A2
11.6% HB F

so what do you think?

Manal

--- End quote ---

OK, even if there are 3 types of Hb, the sum of all the percentages will be 100% and even so, if the Total Hb. is low then any type of Hb will also be low no matter how high percent they show. It's just like Andy said. You want to bake a bread but you don't have enough flour. Let me try to re explain what Andy said.

Rye flour is HbF and Wheat flour is HbA

Consider it as you need four cups of wheat flour but you have only one cup of flour out of which only a spoon full is Wheat flour and rest is rye flour.

This makes rye flour 98% of 1 cup but you need 4 cups!!! So you can't bake bread!!

And if you had 4 cups of rye flour,(by inducing HbF with hydroxyurea or wheat-grass) the bread would bake but will not taste good as the Wheat flour bread

:rotfl

Take care, Peace!

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