Anemia

What sample is needed for an Anemia workup?

1. EDTA blood is needed.
2. For RBC morphology, a direct smear is preferred.`
3. Bone marrow is also advised.
4. Also, a bone biopsy may be needed.

How will you define Anemia?

1. Anemia is a decrease in hemoglobin concentration depending on the patient’s age and sex.
   1. The diagnostic criteria are low hemoglobin, low hematocrit (Hct), or decreased RBC count.

Criteria for the anemia

What are the criteria for anemia?

1. Hemoglobin:
   1. Male = Hb <13.5 g/dL.
   2. Female = Hb 11.5 g/dL.
   3. 2 years to puberty = 11.0 g/dL.
   4. A Newborn = 14.0 g/dL is taken as a lower limit because of the high Hb.
2. Hematocrit (Hct)
   1. Male = <42%.
   2. Female = <37%.
3. In a broad sense, anemia is the inability of the blood to supply adequate O2 to the tissue for proper metabolism.
4. These are the most common hematological disorders.
5. The diagnosis is essential for the physician to treat the cause of anemia.

What are the factors for effective erythropoiesis?

1. Level of iron and cobalt.
2. Vitamin B12.
3. Vitamin B6.
4. Riboflavin.
5. Thiamine.
6. Vitamin C.
7. Vitamin E.
8. Hormones like:
   1. Androgens.
   2. Thyroxine.

What are the types of Hemoglobin?

To understand the anemias, it is better to know the hemoglobin types and structure:

What is the role of hemoglobin in O2 transport (Hb/O2 dissociation curve)?

1. The RBCs carry O2 from the lung to the tissue and bring CO2 in the venous blood to the lung.
2. This is dependent upon the 2,3-diphosphoglycerate (2,3-DPG).
3. When the O2 is unloaded, the β-chain of Hb has pulled apart, permitting the entry of the metabolites 2,3-DPG resulting in a lower molecule affinity for O2.

4. O2 saturation is an indicator of the % of Hb saturated with O2.
5. When 92% to 100% of the Hb carries O2, the tissues adequately provide the O2 supply, which means normal O2 dissociation.
6. Normally O2 exchange takes place:
   1. 95% saturated arterial blood with a mean arterial O2 tension of 95 mmHg.
   2. 70% saturated venous blood with a mean venous O2 tension of 40 mmHg.
   3. So the curve’s normal position depends upon the concentration of 2,3-DPG, H+ ions, and CO2 in the RBCs and the Hb molecule structure.

Hemoglobin-Oxy and Deoxy Hemoglobin

What are the functions of Hemoglobin?

1. RBCs in arterial blood carry O2 from the lungs to the tissue and take back CO2 in the venous blood.

RBC (Hemoglobin) role in oxygenation

1. This main function is with the help of hemoglobin (Hb) molecules, as the Hb molecule load and unload the O2.
2. α1β1 and α2β2 globin stabilize the molecule.

How will you classify Anemia?

Anemia may be classified roughly based on Hb level:

1. Severe anemia when the Hb is <7 g/dL.
2. Moderate when the Hb is  7 to 10 g/dL. This group will not produce evident S/S. in most cases.

How will you classify Anemia on the basis of RBC morphology?

1. Normochromic and normocytic anemias are due to:
   1. Anemia of acute hemorrhage.
   2. Hemolytic anemia.
   3. Anemia due to chronic diseases.
2. Hypochromic and microcytic anemias are due to:
   1. Iron deficiency anemia.
   2. Thalassemia.
3. Normochromic and macrocytic anemias are due to:
   1. Vit. B12 deficiency.
   2. Folate deficiency.
      1. Normochromic and macrocytic anemia is a late event in vitamin B12 and folate deficiency.
      2. Chatgpt says normochromic or hypochromic.

How will you classify anemia on the basis of physiologic abnormality?

1. Defective maturation of erythropoiesis.
2. Hemolytic anemia is where the increased breakdown of the RBCs occurs.
3. Defect due to an increase in RBC precursors compared to the degree of anemia.

How will you classify the anemia on the basis of etiology?

1. Increased RBC destruction due to intra or extra red blood cell defects.
2. Increased blood loss, which may be acute or chronic.
3. Defective RBC formation due to a lack of factors necessary for erythropoiesis.

Anemia classification based on the category:

1. Increased destruction of the RBCs
   1. Hemolytic anemia (nonimmune).
   2. Immune hemolytic anemia.
2. Anemia due to blood loss in hemorrhage.
3. Nutritional deficiency like folate or vitamin B12 deficiency.
4. Toxicity due to drugs.
5. Infections.
6. Infiltration of the bone marrow by the cancer cells.
7. Hereditary or acquired defect in the RBCs.
8. Hematopoietic stem cell arrest or damage.
9. Idiopathic or unknown cause.

How will you classify the anemia on the basis of RBC indices?

1. Normocytic:
   1. MCV is 80 to 100 fl (femtoliter).
   2. MCHC = 32 to 36%
2. Macrocytic:
   1. MCV = >100 fl.
3. Microcytic and hypochromic.
   1. MCV = <80 fl.
   2. MCHC = <32%.
      

      Type of anemia	MCV fl	MCHC%
      Normocytic and normochromic	80 to 100	32 to 36
      Microcytic and hypochromic	<80	<32
      Macrocytic	>100

Differentiating points of various anemias:

What are the Laboratory Criteria for the Diagnosis of Anemias?

1. Hemoglobin when it is less than 12 to 13 G/dL.
2. Hematocrit when it is less than 36 to 41%.
3. Reticulocyte count was normal at 0.5 to 1.5%.
4. MCV is a better choice for classifying the anemias and their differentiation. This is useful for the screening of occult alcoholism.
5. If MCV is high, then advise:
   1. Reticulocytes count.
   2. Vit.B12.
   3. Folate level.
6. If MCV is low, advised:
   1. Serum Iron.
   2. Iron binding capacity (TIBC).
   3. If the above two tests are low, advise Ferritin and Bone marrow examination.
   4. If normal, then advise electrophoresis.
7. If MCV is normal, then advise:
   1. Serum Iron.
   2. Iron Binding Capacity. (TIBC).
   3. Comb’s test.
   4. Peripheral blood for RBC morphology.

How will you do the routine workup of the patient with anemias?

1. The patient’s detailed clinical history for diagnosis, physical examination, signs, and symptoms with the following lab workup.
2. Hemoglobin and hematocrit.
3. Red blood cell count.
4. Blood indices.
5. MCH has limited value in the differential diagnosis of anemias. This is instrumental calibration.
6. MCHC is also instrumental calibration, and changes occur very late in the iron-deficiency anemia when anemia is very severe.
   1. This is better to evaluate hypochromasia than MCH.
7. Red cell distribution width (RDW) helps to classify the anemia with the help of MCV.
   1. RDW is more sensitive to the differentiation of the microcytic anemia than the macrocytic RBCs cause.
   2. This has no value in patients without anemia.
8. Serum iron (Normal = 50 to 150 µg/dL).
   1. Serum total iron helps in the diagnosis of anemia.
   2. It differentiates between hemochromatosis and hemosiderosis.
   3. It should be measured along with TIBC for evaluation of iron deficiency.
   4. This also helps to evaluate acute iron toxicity in children.
9. Total iron-binding capacity (TIBC = Normal = 250 to 450 µg/dL).
   1. It helps in the differential diagnosis of anemias.
   2. It should be done along with serum iron to evaluate the % saturation for the diagnosis of iron deficiency anemia.
10. Transferrin: Serum Transferrin level is needed for the D/D of the anemia.
11. Percent transferrin saturation (normal % transferrin saturation = 20% to 50%).
    1. Calculation of the % transferrin saturation = Serum iron ÷ TIBC x 100 = Transferrin normally 33% is saturated.
    2. This is used for the D/D of the anemias.
    3. This helps in the screening of hereditary spherocytosis.
12. Ferritin: Serum ferritin (normal = 20 to 250 ng/dL).
    1. It correlates with the total body iron stores.
    2. It differentiates iron deficiency or excess.
    3. It correlates with total body iron stores.
    4. It will predict and monitor iron deficiency.
    5. It will give an idea about the effectiveness of iron-deficiency anemia treatment.
    6. It differentiates iron deficiency from chronic diseases.
    7. It monitors the iron status in patients with chronic kidney diseases with or without dialysis.
    8. It is used to study the population’s iron level and response to iron supplements.
    9. It can detect iron overload and monitor iron accumulation.
    10. It can help to guide the response to iron depletion therapy.
13. Peripheral blood smear.
    1. This will inform the abnormality of the RBC shape, size, and any inclusions.
    2. There is a dimorphic picture in a mixed deficiency of iron, vitamin B12, or folate; there are microcytes and macrocytes. In this case, blood indices may be normal.
    3. Also, find the abnormal white cells and the assessment of the platelets.
    4. It can find blast cells like normoblast or granulocyte blast cells.
14. Reticulocyte count.
    
    1. The normal range is 0.5 to 2.5%, and the absolute count is 25 to 125 x 10⁹/L.
    2. Reticulocytes are raised in anemia because of the raised level of erythropoietin.
    3. After the acute hemorrhage:
       1. Erythropoietin level rises in 6 hours.
       2. Reticulocyte level increases in 2 to 3 days, and the peak level reaches 6 to 10 days.
       3. Reticulocytes will be raised until the Hb becomes normal.
    4. In the case of anemia, if there is no raised reticulocyte count, it means bone marrow abnormality or lack of erythropoietin stimulus.
15. White blood cells count and platelets count. This will rule out the pancytopenia from the anemia.
    
    1. In hemolysis or hemorrhage, the neutrophils and the platelets are raised.
    2. In leukemias, the white cells are also raised.
16. Bone marrow examination.
    1. Bone marrow may be aspirated or can take the biopsy.
    2. This will give the cellularity like myeloid: erythroid ratio, and the presence of abnormal cells like cancer cells infiltrate.
    3. Can do Special stains like iron.

Anemia workup

What are the signs and symptoms of anemia?

Clinically, S/S seen are:

1. The main symptoms are due to cardiovascular system adaptation.
   1. Increased stroke volume, tachycardia, and the Hb O2 dissociation curve changes.
      1. Hyperdynamic circulation leads to tachycardia, a bounding pulse, systolic murmurs, especially at the apex, and cardiomegaly.
      2. Older adults may find S/S of congestive heart failure.
2. In some patients with anemia, there is no S/S, while mild anemia may have severe S/S.
3. Acute onset effect: There is an effect on the speed of onset; acute onset has more S/S compared to the slow onset.
4. The severity of the anemia: In the case of mild anemia, there is no S/S.
   1. When the Hb is <9 to 10 g/dL, it may show S/S.
   2. Even Hb as low as 6 g/dL may not produce severe S/S.
5. Age: Older people tolerate less than young people.
6. There is pallor on the face and better judged from the tongue.
7. The patient will feel weakness and fatigue.
8. There are lethargy and malaise.
9. On exertion, there is dyspnoea and palpitation.
   1. The older patients may have cardiac failure, angina, or intermittent claudication or confusion.
   2. This may cause retinal hemorrhage, and this may complicate anemia of rapid onset.
10. The patient may like to eat clay, ice, and starch.
11. The patient may have syncope after the exercise.
12. They may have dizziness and headaches.
13. There is tinnitus or vertigo.
14. Usually, these patients are irritable.
15. These patients may have gastrointestinal symptoms.
16. These patients may have difficulty sleeping or concentrating.

What are the specific Signs of anemia?

1. K0ilonychia, which is spoon-shaped nails. This is usually seen in:
   1. Iron-deficiency anemia.
   2. Jaundice with hemolytic or megaloblastic anemia.
   3. Leg ulcers in Sickle cell anemia.
   4. Other hemolytic anemias.
   5. Bone deformities are seen in thalassemia and other severe congenital anemia.
   6. There may be infections and bruising with anemia due to bone marrow failure related to thrombocytopenia and neutropenia.

Normal adult blood indices values:

What are the types of Anemias?

Anemia is divided based on RBCs indices (MCV) into the following broad categories:

1. Microcytic, MCV <80 fl.
2. Normocytic, MCV 80 to 100 fl.
3. Macrocytic, MCV >100 fl.

How would you describe Normochromic and normocytic Anemia?

Lab findings:

1. Low hemoglobin.
2. Normal MCV 80 to 95 fL.
3. Normal MCH ≥27 pg.
4. Normal MCHC.
   1. Mostly, these are due to acute blood loss.

The peripheral blood smear shows normal-looking RBCs and normal RBCs indices.

1. 1. The RBCs produced by the bone marrow are normal, but the number of RBCs in circulation is reduced for many reasons.

What are the causes of normochromic and normocytic anemia?

1. Iron deficiency in the early stages.
2. Acute blood loss.
3. Chronic diseases of the kidneys and the liver.
4. Infiltration by leukemia and multiple myeloma.
5. Drugs like chloramphenicol cause aplastic anemia.
6. Acquired hemolytic anemia may be from the prosthetic surgery of the heart.
7. Pregnancy due to increased plasma volume.
8. Overhydration.

Anemia normocytic and differential diagnosis

How would you describe microcytic and hypochromic anemia?

1. These are the most common types of anemia, and iron deficiency is the most common cause.

What are the causes of microcytic hypochromic anemia?

1. This is due to iron deficiency caused by decreased iron intake in the diet or impaired absorption.
2. Iron deficiency anemia.
3. Lead poisoning.
4. Thalassemia.
5. There may be an increased iron loss due to chronic bleeding.
6. There may be an abnormality in iron metabolism.
7. Increased demand by the body in:
   1. Infancy.
   2. Pregnancy.
   3. Lactation.
8. Due to cancer.
9. Hemorrhoids.
10. Hookworms.
11. Drugs like salicylates (aspirin).

Anemia microcytic differential diagnosis

How will you diagnose microcytic hypochromic anemia?

1. Low hemoglobin, males <12 g/dL and females <10 g/dL.
2. Low MCV <80 fL.
3. MCH < 27 pg.
4. Findings in the iron-deficiency anemia:
   1. Serum iron is deficient.
   2. TIBC is very high.
   3. Serum ferritin = <10 ng/dL
   4. Free RBCs protoporphyrin is high.
   5. RDW is high.
   6. RBC survival time is slightly less.
5. Peripheral blood smears show microcytes and pale, hypochromic RBCs.
   1. There may be leucopenia.
   2. Platelets are high in case of bleeding.
   3. Reticulocytes are lower than expected in the degree of anemia.
6. Bone marrow shows erythroid hyperplasia.
   1. Iron stain shows deficient iron.

Anemia showing microcytic hypochromic RBCs

How would you describe Macrocytic Anemia?

1. These are megaloblastic anemias resulting from the deficiency of vitamin B12, folic acid, or a combination of both.

What are the lab findings of macrocytic anemia?

1. Low hemoglobin.
2. MCV > 99 fL.
3. The peripheral blood smear shows macrocytosis and many hypersegmented neutrophils.
4. Occasionally, you may see leucopenia and thrombocytopenia.

What are the causes of macrocytic anemia?

1. Vitamin B12 deficiency.
2. Folic acid deficiency.
   1. Or a combination of both
3. Chemotherapy side effects.
4. In the case of hydantoin therapy.

Macrocytic anemia differential diagnosis

 How would you describe Hemolytic Anemia?

How will you define hemolytic anemia?

1. Hemolytic anemia is a disorder associated with the decreased life span of RBCs.
2. The shortened life span of RBCs may be an intracorpuscular or extracorpuscular abnormality.
3. The severity depends on the rate of destruction and the removal of RBCs.
4. The normal bone marrow can increase its work by 6 to 8 folds, so the anemia may not be apparent until the RBC’s life span reaches only 20 days.

What are the causes of hemolytic anemia?

1. Intrinsic defects like:
   1. Hereditary defects like:
      1. An abnormal RBC membrane detects hereditary spherocytosis.
      2. Inherited RBC enzyme disorders like G-6-phosphate dehydrogenase deficiency.
   2. Disorders of abnormal hemoglobin production like sickle cell disease.
   3. Thalassemia syndrome.
   4. Paroxysmal nocturnal hemoglobinuria.
2. Extrinsic defects like:
   1. Chemical and toxic agents.
   2. Infection causing hemolysis.
   3. Hypersplenism.
   4. Immune hemolytic anemia.

How will you diagnose hemolytic anemia?

1. There is a raised bilirubin level.
2. There are increased reticulocytes.
3. There is polychromasia.

Hemolytic anemia showing polychromasia

Table showing findings in various anemias:

Characteristic findings in various Anemias:

Classification of anemia based on RDW:

Mean corpuscular volume (MCV) and Red cell distribution (RDW) in relation to various diseases:

Abnormalities of RBCs and their etiology:

Type of RBC abnormality	Etiology for the abnormality
Microcytic RBCs Sickle cell Hb structure	Iron-deficiency anemia Thalassemia Sideroblastic anemia Lead poisoning
Macrocytic	Megaloblastic anemia Liver diseases Myelodysplastic syndrome Increased reticulocyte count
Spherocytes	Hereditary spherocytosis Hemolytic anemia Post transfusion
Target cells	Thalassemia Liver diseases Sideroblastic anemia Hemoglobinopathies
Teardrop cells	Severe anemia Pernicious anemia Myeloproliferative anemia
Elliptocytes	Hereditary elliptocytosis Thalassemia Iron-deficiency anemia
Sickle cells	Sickle cell anemia Sickle-thalassemia
Stomatocytes	Malignant tumors Acute alcoholism
Burr cells	Renal diseases Liver diseases Bleeding gastric ulcer Severe burns
Acanthocytes	Alcohol intoxication Post splenectomy Vitamin E deficiency Congenital abetalipoproteinemia
Helmet cells	G-6-PD deficiency Pulmonary emboli
Schistocytes	Hemolytic uremic syndrome Thrombotic idiopathic thrombocytopenia (ITP) Disseminated intravascular coagulopathy (DIC)

Summary of lab findings in various anemias:

Panic values are:

1. Hb = <5 g/dL or >20 g/dL
2. Hct = <20 % ( leads to heart failure)  or > 60% (leads to spontaneous clotting).

Questions and answers: