Acquired RBC Anemias - Symptoms, Causes, Diagnosis, and Treatment

What Is Anemia?

Anemia is defined as a decrease in hemoglobin level (a protein molecule in red blood cells)below normal for that age and sex. The average hemoglobin level in adult males varies from 13 to 16 g/dL and 12 to 15 g/dL in females. There are various types of anemias, and they are classified based on the morphology of red blood cells (RBC) and the amount of hemoglobin in each cell.

These changes in human beings can either be:

• Acquired (when the person acquires during the lifetime) (or)

• Congenital (being anemic at the time of birth).

The following are the acquired RBC anemias;

1. Iron deficiency anemia.

2. Megaloblastic anemia.

3. Hemolytic anemia.

4. Aplastic anemia.

1. Iron Deficiency Anemia:

Iron deficiency anemia is the most common form of anemia. Its prevalence is higher in developing countries. There is a lack of healthy red blood cells in this anemia, making it difficult to carry enough oxygen to tissues.

1. Causes of Iron Deficiency Anemia

The common causes of iron deficiency anemia are,

a). Blood loss:

• Acute blood loss caused by accident or surgery.

• Chronic blood loss occurring due to gastritis, peptic ulcer, hookworm infestation (Ancylostoma duodenale and Necator americanus), hemorrhoids, and menstrual loss.

b). The iron deficiency can occur during physiological states with high iron demand during adolescence and pregnancy.

c). Decreased absorption or malabsorption due to gastrectomy, achlorhydria, or diseases of the small intestine such as Crohn’s disease can also lead to iron-deficiency anemia.

d). Inadequate diet.

2. Common Symptoms to Identify Iron Deficiency Anemia

Iron deficiency anemia may specifically show the following symptoms,

• Craving for ice cubes or cold treats.

• Corners of the mouth get inflamed.

• Spoon-shaped nails.

• Mild splenomegaly (enlargement of the spleen).

• Difficulty in swallowing due to formation of the post-cricoid web (Plummer Vinson syndrome).

• Headache.

• Fatigue.

• Pale skin.

3). Source and Daily Requirement

Iron is mainly available from a diet source that is rich in liver, meat, beans, green vegetables, and jaggery (plant-based iron). Milk is a poor source of iron, and the daily iron requirement is 1 mg in males and 2 mg in females.

4). Treatment for Iron Deficiency Anemia

• Oral Iron Therapy: For iron deficiency anemia, the drug of choice is ferrous sulfate (200 mg). However, 60 % of patients will develop intolerance to oral iron, leading to abdominal pain, nausea, and vomiting. This treatment is given for a longer duration, from 6 months to 12 months.

• Parenteral Iron Therapy: IV (intravenous) iron therapy is given to people who cannot tolerate oral iron or in case of malabsorption.

• Red Blood Cell Transfusion: It is indicated in people with severe anemia and who need immediate intervention.

2. Megaloblastic Anemia:

Megaloblastic anemia is characterized by a very large and decreased number of red blood cells.

A) Causes of Megaloblastic Anemia

The most important causes of megaloblastic anemia are folic acid deficiency and vitamin B12 deficiency (cobalamin) because of malnutrition and pregnancy. Vitamin B12 and folic acid are essential for DNA (deoxyribonucleic acid) synthesis, and their deficiency may lead to impaired cellular proliferation and maturation. Important causes of cobalamin and folic acid deficiency are,

a). Causes of Cobalamin:

• Decreased intake of vegetables.

• Less absorption of food due to diseases of the terminal ileum such as sprue, Crohn’s disease, etc., bacterial proliferation, and presence of fish tapeworm (Diphyllobothrium latum) infestation.

b). Causes of Folic Acid Deficiency:

• Low intake of food or having an unbalanced diet.

• Alcohol intake.

• Intake of drugs such as Phenytoin, Methotrexate, Pyrimethamine, and Trimethoprim.

B). Clinical Epitome:

• Mild jaundice due to raised plasma unconjugated bilirubin.

• Purpura may rarely occur due to thrombocytopenia.

• The spleen may be enlarged.

• Anorexia (eating disorder).

• Weight loss.

• Diarrhea.

• Smooth and beefy red tongue.

• Paresthesia (numbness of hands, arms, legs, or feet).

• Ataxia (lack of muscle control).

• Loss of memory.

C). Necessary Wellspring on:

The intake of the daily source of vitamin B12 (cobalamin) should be 2.5 µg. Cobalamin must be supplemented in the diet, and the only dietary source of cobalamin is animal products such as meat and dairy foods.

The average daily requirement of folic acid is 50 to 100 µg, although the demand may increase several folds during pregnancy. Folic acid is found in both animal and plant-based sources.

D). Treatment for Megaloblastic anemia:

• Packed Red Blood Cell Transfusion: In patients with severe anemia along with cardiac symptoms, this transfusion is made.

• Cobalamin Deficiency: Intramuscular Cyanocobalamin with the initial dose of 1 mg per week for two months followed by 1 mg per month.

• Folate Deficiency: Initial dose of Folic acid is 1 mg per day orally, and in case of malabsorption, a higher dose of 5 mg daily may be needed.

3. Hemolytic Anemia:

The normal lifespan of red blood cells is 90 days to 120 days, and Around one percent of red blood cells are destroyed in the spleen, which is reproduced by the bone marrow every day. This hemolytic anemia occurs due to an increase in premature destruction of red blood cells when the bone marrow is unable to replace them adequately. This could be congenital or acquired.

A). Causes of Acquired Hemolytic Anemia

The causes of acquired hemolytic anemia could be due to destruction of red blood cells by the spleen or autoimmune reactions. It can also occur due to destruction of RBCs due to,

• Tumors.

• Infection.

• Medication side effects.

• Autoimmune disorders.

• Lymphoma.

• Leukemia.

The causes of hemolytic anemia are,

• Infectious hepatitis.

• Enlarged spleen.

• Typhoid fever.

• Epstein-Barr virus.

• E. coli toxin.

• Lymphoma.

• Tumors.

• Leukemia.

• Systemic lupus erythematosus (SLE).

B). Diagnosis of Hemolytic Anemia

The common symptoms are,

• Fatigue.

• Paleness of the skin.

• Fever.

• Confusion.

• Weakness in doing physical activity.

• Lightheadedness.

• Dizziness.

Other common signs and symptoms are,

• Jaundice.

• Dark urine.

• Heart murmur.

• Enlarged spleen.

• Increased heart rate.

• Enlarged liver.

C). Treatment for Hemolytic Anemia

• Packed Cell Transfusions: This supportive treatment is needed initially, but repeated transfusions may cause iron overload.

• Folic Acid: 5 mg folic acid is given when there is an increased demand.

• Corticosteroid medicines: These medications are given in case the condition is immune-mediated.

• Surgery: It is done to remove the spleen.

4. Aplastic Anemia:

It occurs when the body does not produce enough red blood cells.

A). Causes of Aplastic Anemia

The red blood cells are produced in the stem cells of the bone marrow. In aplastic anemia, these stem cells are damaged, which may result in an empty (aplastic) bone marrow or fewer RBCs (hypoplastic). The common cause is that our immune system attacks our own stem cells in the bone marrow. The other factors that affect the bone marrow are:

• Radiation and chemotherapy treatments.

• Exposure to toxic chemicals such as pesticides, benzene, and insecticides.

• Use of drugs that are used to treat rheumatoid arthritis and some antibiotics.

• Autoimmune disorders.

• Viral infections such as hepatitis, cytomegalovirus, Epstein-Barr, HIV (human immunodeficiency virus), and parvovirus B19.

• Pregnancy.

B). Clinical Presentations

The common presentation is bleeding, and the excessive tendency is due to thrombocytopenia (low platelet count in the blood) which may present as,

• Gum bleeding.

• Unexplained bruising.

• Nose bleeding.

• Prolonged bleeding from cuts

• Menstrual flow.

• Retinal hemorrhage.

• Intracranial hemorrhage may also occur.

The other symptoms are,

• Shortness of breath.

• Fatigue.

• Rapid or irregular heart rate.

• Frequent or prolonged infections.

• Pale skin.

• Skin rash.

• Headache.

• Dizziness.

• Fever.

C). Treatment for Aplastic Anemia:

• Bone Marrow Transplantation (BMT): This is preferred in younger people (less than 40 years of age).

• Immunosuppressive Therapy: People who cannot undergo BMT can benefit from this treatment, and the immunosuppressive agents are anti-thymocyte globulin or anti-lymphocyte globulin.

• Packed Cell Transfusion: In case of severe anemia, platelet cell transfusion is recommended.

• Platelet values should be maintained at or more than 10,000 per microliter.

• Infections are aggressively treated with broad-spectrum antibiotics and antifungals.

Conclusion:

Anemia is easily treatable when it is found in the early stages and is curable with proper medical intervention. The treatment might differ based on the type of anemia. However, hospitalization is a must in severe cases. When there are any abnormal symptoms, consult the doctor to avoid severe complications.