Anemia Flashcards
The transport and storage of iron are largely mediated by three proteins they’re?
transferrin, transferrin receptor 1 (TfR1)
and ferritin.
Some iron is stored in the macrophages as ___&___
What’s the difference ?
ferritin and
haemosiderin
Ferritin is a water-soluble protein–iron complex and hemosiderin is not
What are the causes of a hypochromic microcytic anaemia.
.
These include lack of iron (iron deficiency) or of iron release
from macrophages to serum (anaemia of chronic inflammation
or malignancy), failure of protoporphyrin synthesis (sideroblastic
anaemia) or of globin synthesis (α- or β-thalassaemia). Lead also
inhibits haem and globin synthesis
At the end of their life, red cells
are broken down in the macrophages of the reticuloendothelial
system and the iron is released from haemoglobin, enters the
plasma and provides most of the iron attached to transferrin.
Only a small proportion of plasma transferrin iron comes from
dietary iron, absorbed each day through the duodenum and
jejunum. Iron in excess of that needed for haemoglobin synthesis is also released from erythroblasts and erythrocytes to
plasma transferrin.
What’s the distribution of iron in the body?
Hemoglobin 65
Ferritin & hemosiderin 30
Myoglobin 3.5
Haem enzymes 0.5
Transferrin bound fe 0.1
This tissue iron is less likely to become depleted than haemosiderin, ferritin and haemoglobin in states
of iron deficiency, but some reduction of these haem-containing
enzymes may occur
What’s the major hormonal regulator of iron homeostasis and how fore it work?
When it’s raised I’m the blood it indicates?
Hepcidin is a polypeptide produced by liver cells. It is the
major hormonal regulator of iron homeostasis
. It inhibits iron release from macrophages, from intestinal
epithelial cells and from other cells by its interaction with
the transmembrane iron exporter, ferroportin
. It accelerates degradation of ferroportin protein. Raised hepcidin levels
therefore profoundly affect iron metabolism by reducing its
absorption and its release from macrophages.
Factors Influencing Hepcidin Production
High iron levels increase hepcidin production to lower iron in the blood.
Low iron levels and increased red blood cell production reduce hepcidin production to allow more iron absorption.
i.e during erythtopiosis: Early red blood cells (erythroblasts) produce erythroferrone, a protein that suppresses BMP signaling for hepcidin.
Hypoxia suppresses hepcidin, leading to more iron absorption.
Inflammation increases hepcidin, reducing iron to limit bacterial growth.
During inflammation, cytokines like interleukin-6 (IL-6) increase hepcidin production.
Factors Influencing Hepcidin Production
High iron levels increase hepcidin production to lower iron in the blood.
Low iron levels and increased red blood cell production reduce hepcidin production to allow more iron absorption.
i.e during erythtopiosis: Early red blood cells (erythroblasts) produce erythroferrone, a protein that suppresses BMP signaling for hepcidin.
Hypoxia suppresses hepcidin, leading to more iron absorption.
Inflammation increases hepcidin, reducing iron to limit bacterial growth.
During inflammation, cytokines like interleukin-6 (IL-6) increase hepcidin production.
Factors Influencing Hepcidin Production
Iron Status:
Iron Overload (High Iron Levels):
Process:
When iron levels are high, a protein called diferric transferrin (which carries iron) signals the liver cells.
This signal causes liver cells to produce bone morphogenetic proteins (BMPs), particularly BMP6.
BMP6 binds to receptors (BMPRs) on liver cells, forming a complex with other proteins (TFR2, HJV, HFE)
This complex activates signaling proteins (SMADs) that go to the cell nucleus and stimulate hepcidin production.
Hepcidin then works to reduce iron absorption from the diet and release of iron from storage.
Example: Think of BMP6 as a traffic light turning green, signaling more hepcidin cars to move out from the liver garage to reduce iron traffic in the bloodstream.
What are the factors favouring absorption and those that reduce
Ferrous form (Fe2+)
Acids (hydrochloric acid, vitamin C)
Solubilizing agents (e.g. sugars, amino acids)
Reduced serum hepcidin
Ineffective erythropoiesis
Pregnancy
Hereditary haemochromatosis
Inorganic iron
Reduce
Haem iron
Ferric form (Fe3+)
Alkalis – antacids, pancreatic secretions
Precipitating agents – phytates, phosphates, tea
Increased serum hepcidin
Decreased erythropoiesis
Inflammation
What’s the normal hg and pcv for a
Adult male
Adult female non P
Adult female P
Children 6-12Y
Children 6M to 6Y
Infants 2-6M
Newborn
Adult males
13-17
40-50
Adult females(nonpregnant)
12-15
38-45
Adult females(pregnant)
11-14
36-42
Children, 6-12yrs
11.5-15.5
37-46
Children, 6mths-6yrs
11-14
36-42
Infants, 2-6mths
Newborns
9.5-14
13.6-19.6
32-42
44-60
What are the categories of anemia. Severity with hg figures
Mild : lower limit of normal to 10g/dl
Moderate : 7-10g/dl
Severe : <7g/dl
Clinical evaluation : signs and symptoms of anemia
Signs and symptoms :
easy fatiguability, effort dyspnoea, tachycardia, pallor, ccf in severe cases
Sure, let’s break down this text about determining the cause of anemia into simpler terms with some examples.
To find out why someone has anemia, doctors look at the signs and symptoms that might come from the anemia itself or from the illness causing it.
Anemia can cause various symptoms, such as:
- Easy Fatiguability: Getting tired very easily.
- Effort Dyspnea: Shortness of breath during physical activity.
- Tachycardia: A fast heartbeat.
- Pallor: Pale skin.
- CCF (Congestive Cardiac Failure): In severe cases, the heart struggles to pump blood effectively.
Doctors will ask about different aspects of a person’s history, such as:
- Chronic Blood Loss: Ongoing loss of blood, like from heavy menstrual periods or gastrointestinal bleeding.
- Recurrent Pregnancies: Multiple pregnancies can deplete iron stores.
- Pica: A strong desire to eat non-food items, like dirt or ice, which can be linked to iron deficiency.
- Chronic Alcoholism: Drinking a lot of alcohol over a long time can affect the body’s ability to produce healthy blood cells.
-
Drug History: Certain medications can cause different types of anemia. For example:
- Hypoplastic Anemia: A condition where the bone marrow doesn’t make enough blood cells, can be caused by drugs like chloramphenicol.
- Macrocytic Anemia: Caused by drugs like methotrexate, which affect how the body uses folic acid.
- Iron Deficiency Anemia (IDA): Drugs like aspirin can cause stomach bleeding, leading to anemia.
- Hemolytic Anemia: Caused by drugs like methyldopa that make the body destroy its own red blood cells.
- Jaundice or Gallstones: These conditions can indicate issues with red blood cell breakdown, which might contribute to anemia.
- Chronic Illness: Long-term diseases, like kidney disease or cancer, can lead to anemia.
- Prevalent Forms of Anemia in the Area: Certain types of anemia are more common in specific regions. For example, Sickle Cell Anemia (SCA) is more prevalent in some areas and can help guide the diagnosis.
Imagine a patient named Jane who goes to the doctor because she feels extremely tired all the time and gets out of breath just walking up a few stairs. The doctor notices she has pale skin and a fast heartbeat. Jane mentions that she has very heavy periods each month and has had three children in the last five years. She also tells the doctor that she sometimes craves and eats ice.
The doctor suspects Jane might have iron deficiency anemia (IDA) due to her history of heavy menstrual bleeding and multiple pregnancies. The craving for ice, a type of pica, also supports this. Further tests would likely confirm the diagnosis and help determine the right treatment.
