We hear a lot about “Hemoglobin” in the context of “Anemia” – an inevitable consequence in Chronic Kidney Failure (among other causes). But do we really understand what Hemoglobin is & what makes it that important?
With the 1st post in the “Anaemia in CKD” series, let us explain this crucial topic.
WHAT IS HEMOGLOBIN?
Hemoglobin is a “Composite Bio-molecule”, meaning it is made of MORE THAN ONE TYPE of constituents normally found within the human body. As the name itself suggests, it comprises of Globin Proteins that literally piggy-back Heme – the iron-containing Pigment Molecules responsible for the glorious red colour of our blood. Since Heme contains Iron, Biochemists also call Hemoglobin a “Metallo-protein”.
In normal health, Hemoglobin or Hb as it is known in short is found happily ensconced within every Red Blood Corpuscle (RBC) in the human body. Fresh stock of Hb begins appearing there, every time our body forms a new RBC.
A healthy adult male contains 13-18 g/dL of Hb while the corresponding range for adult females is 12-15 g/dL
WHAT DOES IT DO?
Hemoglobin is the Oxygen transport molecule of our body and is absolutely essential for life.
Strictly speaking in terms of molecular biology, when we talk about Hemoglobin molecule as a whole, there are 4 Heme groups, each containing 1 Iron core and the respective Globin protein tails. These are held together by a kind of “chemical force” within our body to form 1 Hemoglobin molecule. It is important that we know this to understand how Hb carries out its job of transporting Oxygen within our body.
The “Heme” part of Hb is the one that attaches to Oxygen. It owes this capability to Iron present in it. Since there are 4 Heme groups in 1 Hb molecule, every Haemoglobin molecule is capable of carrying 4 Oxygen molecules at a time. The “Globin” part acts as a “Jetpack” protein that allows for Oxygen transport from Hb in the RBCs to other tissues in need of Oxygen.
SIGNIFICANCE OF HEMOGLOBIN IN ANAEMIA
In Anaemia (from all causes), we face a shortage of Red Blood Corpuscle (RBC) production for varied cause-specific reasons. Low RBC count implies a fall in total Hemoglobin levels in the body. As explained above, this means an unfortunate compromise in our efficient Oxygen Transport system within our body. Consequently, tissues face “fuel-shortage” over time and end up getting malnourished.
The Heart senses this situation and tries to help by pumping faster than normal to transport more RBCs to tissues at a time. While it’s very kind of our Heart to be that thoughtful, this arrangement is only momentarily beneficial before it tires out our heart and makes us feel “out of breath” easily. Simultaneously, in Anaemias NOT related to kidney disease, healthy Kidneys jump into action by producing more of Erythropoietin — the RBC-forming hormone. This signals our body to generate more RBCs (containing Hemoglobin) such that the oxygen shortage to tissues can be alleviated. But if it is the Anaemia in Chronic Kidney Disease that we are talking about, you can understand where the problem will be with a dip in Erythropoietin hormone levels.
SIGNIFICANCE OF HEMOGLOBIN IN THE TREATMENT OF ANAEMIA
In Allopathy, treatments for Anaemia are singularly focused on alleviating the ill-effects of poor oxygen delivery to tissues due to a low RBC count. And understanding the molecular structure, natural location & oxygen transport function of Hemoglobin helps us see the logic of these treatment protocols.
1. IRON INTAKE
Your doctor will initially start you on Iron Folic Acid capsules to be taken by mouth. Iron is what binds to oxygen within Hb. And Folic Acid helps make more RBCs. So, taking these capsules can help stimulate greater Hb production in your body. This boosts the health of your in-house oxygen transport systems.
In CKD, taking Iron by mouth may stop being beneficial after a certain point of time. Then your doctor may advise an Intravenous Iron infusion (directly to your bloodstream).
2. SYNTHETIC ERYTHROPOIETIN HORMONE (OR ANALOGUES)
In Anaemia due to CKD, Iron alone (whether taken by mouth or by infusion) is ineffective in advanced stages. Until recently, doctors used to add Synthetic Erythropoietin (EPO) Hormone injections or their analogues such as Darbepoietin Alfa at this stage of the treatment plan.
As explained in the above section, this hormone is essential for RBC production. Getting it from outside boosts new RBC production. This raises the overall Hemoglobin content in your body and effectively fights off problems with oxygen transport.
However, recently, the use of these hormone analogues has caused heart problems in some patients. So, your doctor will decide whether to use it or not, depending on your Heart health.
3. BLOOD TRANSFUSION
Let’s consider a situation where something of a sudden, acute nature has caused your RBC count to drop down during your CKD journey. Such a situation can arise with massive blood loss from an injury or perhaps an infection. In these cases, it is essential that RBC numbers are made to rise on an urgent basis.
Measures such as Iron intake or infusion & EPO hormone injections take some time (about 2 weeks) before new RBCs start appearing in the bloodstream. So, using these individually, will not help in urgent scenarios such as the ones above. In such situations, Blood Transfusions in authentic medical care centers are the best approach.
This involves infusing the patient with blood from a donor after:
- Proper screening for diseases transmissible by blood. (Eg: HIV, Hepatitis B etc)
- Matching for the blood group and Rh type.
This ensures that the patient gets an entire Army of Oxygen transporting-RBCs instantly. This helps to immediately address all ill-effects due to poor oxygen delivery to tissues during Anaemia. It proves as a life-saving measure.
Once the patient responds to this approach & is stable, doctors may consider starting/resuming Iron and/or EPO (if it is safe to use in the patient) later on. (Yes, blood transfusions must be chosen carefully, if you are a transplant candidate, but that’s for another day.)
So you see, how understanding Hemoglobin helps you navigate the basics of the mammoth topic called Anaemia.
This was just the beginning though. There are more information boosters to come your way this week in my Anaemia in CKD series. Keep a tab of this space to understand what may be going on within your body even right now!
Stay tuned to All Things Kidney – Official here at https://www.allthingskidney.com
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