Definition Reduced concentration of haemoglobin in the blood. The number of red blood cells in the blood is low.
Normal haemoglobin levels Adult males: 130 to 180 grams per litre Adult females: 120 to 160 grams per litre Levels for children vary with age but are generally 1 to 2 grams lower than adult female values.
Causes of Anaemia1. Anaemia from active bleeding: Heavy menstrual bleeding Wounds Gastrointestinal ulcers Cancers such as cancer of the colon
2. Iron deficiency anaemia: Limited or inadequate iron due to poor dietary intake Stomach ulcers or other sources of slow, chronic bleeding (colon cancer, uterine cancer, intestinal polyps, haemorrhoids, etc.)- all lead to slow loss of iron.
3. Anaemia related to kidney disease: Release of a hormone called the erythropoietin (EPO) from kidney for making red blood cells. Diminished production of erythropoietin in kidneys. This is called anaemia related to chronic kidney disease.
4. Anaemia related to pregnancy: Water weight gain during pregnancy dilutes the blood, which may be reflected as anaemia.
5. Anaemia related to poor nutrition: Vitamin B12 and folic acid are required for the proper production of haemoglobin. Deficiency: inadequate production of red blood cells. Poor dietary intake Strict vegetarians who do not take sufficient vitamins are at risk to develop vitamin B12 deficiency.
6. Pernicious Anaemia: Poor absorption of vitamin B12.7. Sickle cell anaemia: Production of abnormal haemoglobin molecules Crescent-shaped (sickle cells). There are different types of sickle cell anaemia with different severity levels.
8. Thalassemia: Cause quantitative haemoglobin abnormalities An insufficient amount of the correct haemoglobin type molecules is made.
9. Alcoholism: Poor nutrition and deficiencies of vitamins and minerals are associated with alcoholism. Alcohol toxic to the bone marrow and may slow down the red blood cell production.
10.Bone marrow-related anaemia: Anaemia may be related to diseases involving the bone marrow. Some blood cancers such as leukaemia or lymphomas can alter the production of red blood cells and result in anaemia.
11.Aplastic anaemia: Some viral infections may severely affect the bone marrow and significantly diminish production of all blood cells. Chemotherapy (cancer medications) and some other medications may pose the same problems.
12.Haemolytic anaemia: Red blood cells rupture (known as haemolysis) and become dysfunctional. Some forms of haemolytic anaemia can be hereditary with constant destruction and rapid reproduction of red blood cells. This type of destruction may also happen to normal red blood cells in certain conditions, for example, with abnormal heart valves damaging the blood cells or certain medications that disrupt the red blood cell structure.
13.Anaemia related to medications: Side effect in some individuals. The mechanisms are numerous (haemolysis, bone marrow toxicity) and are specific to the medication. Chemotherapy drugs used to treat cancers. Seizure medications, transplant medications, HIV medications, some malaria medications, some antibiotics (penicillin, chloramphenicol), antifungal medications, and antihistamines.
Classification of AnaemiaDepending on the size of RBCs andhaemoglobin content:-1. Hypochromic, microcytic anaemia Small red cells with low Hb Caused by iron deficiency2. Macrocytic anaemia Large red cells Few in number
3. Normochromic normocytic anaemia Fewer normal sized red cells, each with a normal haemoglobin content
Based on concentrations of ferritin,iron, vitamin B12 and folic acid inserum:-1. Deficiency of nutrients necessary for haemopoiesis:- Iron Folic acid and vitamin B12 Pyridoxine, vitamin C
2. Depression of bone marrow caused by:- Toxins (e.g. drugs in chemotherapy) Radiation therapy Diseases of the bone marrow Reduced production of, or responsiveness to, erythropoietin (e.g. chronic renal failure, rheumatoid arthritis, AIDS
The Haematinic Agents Erythropoieti n Iron Vitamin B12 & Folic acid
Erythropoietin (EPO) Growth factor responsible for erythropoiesis. Regulator of the proliferation of committed progenitors (BFU- Burst forming units, CFU- Colony forming units) Absence of EPO: Severe anaemia
Deficienc Increased Sensed release of y of EPO from by kidney oxygen kidney Activates Binds to transcription surface receptors of Bone factors to committed marrowregulate gene erythroid expression progenitors Stimulates Proliferatioexpansion of n and erythroid maturation progenitors
Important for the synthesis of haemoblobin, myoglobin, cytochromes and other enzymes. Major part of dietary iron is in ferric form. Converted to ferrous form before absorption. Two iron transporters present:- Divalent metal transporter 1 (DMT1): Carries ferrous iron from intestinal lumen to the mucosal cell.
Mucosal block: excess iron from mucosal cells oxidized to ferric form and complexed with apoferritin to form ferritin. Ferritin stored in mucosal cells and is lost when they are shed (life span 2- 4days). Iron in plasma bound to transferrin and used for erythropoiesis.
Vitamin B12 and Folic Acid Necessary for DNA synthesis and consequently cell proliferation. Dihydrofolate (FH2) and tetrahydro folate (FH4 ) act as carriers and donors of methyl group in metabolic pathways. FH4 acts as a cofactor and is essential for synthesis of purines and pyrimidines. Active FH4 form maintained by dihydrofolate reductase (enzyme which reduces dietary folic acid to FH4 and
Diagnosis Family history Previous personal history of anaemia or other chronic conditions Medications Colour of stool and urine Bleeding problems Occupation and social habits (such as alcohol intake)
General appearance (signs of fatigue, paleness), jaundice (yellow skin and eyes), paleness of the nail beds, enlarged spleen(splenomegaly) or liver (hepatomegaly), heart sounds, and lymph nodes.
Lab tests for anemia1. Complete blood count (CBC): Determines the severity and type of anaemia (microcytic anaemia or small sized red blood cells, normocytic anaemia or normal sized red blood cells, or macrocytic anaemia or large sized red blood cells) and is typically the first test ordered. Information about other blood cells (white cells and platelets) are also included in the CBC report
2. Stool haemoglobin test: Tests for blood in stool which may detect bleeding from the stomach or the intestines (stool Guaiac test or stool occult blood test).3. Peripheral blood smear: Looks at the red blood cells under a microscope to determine the size, shape, number, and colour as well as evaluate other cells in the blood.
4. Iron level: An iron level may tell the doctor whether anaemia may be related to iron deficiency or not. This test is usually accompanied by other tests that measure the bodys iron storage capacity, such as transferrin level and ferritin level.5. Transferrin level: Evaluates a protein that carries iron around the body.6. Ferritin: Evaluates at the total iron available in the body.7. Folate: A vitamin needed to produce red blood cells, which is low in people with
8. Vitamin B12: A vitamin needed to produce red blood cells, low in people with poor eating habits or in pernicious anaemia.9. Bilirubin: Useful to determine if the red blood cells are being destroyed within the body which may be a sign of haemolytic anaemia.10. Lead level: Lead toxicity used to be one of the more common causes of anaemia in children.11. Haemoglobin electrophoresis: Sometimes used when
12. Reticulocyte count: A measure of new red blood cells produced by the bone marrow13. Liver function tests: A common test to determine how the liver is working, which may give a clue to other underlying disease causing anaemia.14. Kidney function test: A test that is very routine and can help determine whether any kidney dysfunction exists.15. Bone marrow biopsy: Evaluates production of red blood cells and may be done when a bone marrow problem is
Treatment Varies widely and depends on the cause and the severity of anaemia. If anaemia is mild and is found to be related to low iron levels, then iron supplements may be given while further investigation to determine the cause of the iron deficiency is carried out. If anaemia is related to sudden blood loss from an injury or a rapidly bleeding stomach ulcer, then hospitalization and transfusion of red blood cells may be required to relieve the symptoms and
Iron may be taken during pregnancy and when iron levels are low. Oral iron: Fe sulfate, Fe gluconate, Fe fumerate, Fe succinate, Fe ammonium citrate, etc. Parenteral iron: Iron dextran (elemental iron), Iron-sorbitol-citric acid complex.
Parenteral iron is given in the following conditions:- Oral iron is not tolerated: bowel upset is too much. Failure to absorb oral iron: malabsorption, inflammatory bowel disease, rheumatoid arthritis. Non-compliance to oral iron. Severe deficiency with chronic bleeding Rapid eryhthropoiesis
Vitamin supplements in vit B12 and folic acid deficiency. Pernicious anaemia: Monthly injections of vitamin B12 are commonly used to replete the vitamin B 12 levels. Drugs: Cyanocobalamin, Hydroxycobalamin, Methylcobalamin. Duration of medication: initially 30-100 µg/day for 10days followed by 100 µg weekly and then monthly for maintenance- indefinitely or life long.
Folic acid deficiency: oral therapy of folic acid Therapeutic dose: 2-5 mg/day Prophylactic dose: 0.5 mg/day Erythropoietin deficiency/low levels (chronic renal failure): Epoetin α,β (recombinant human erythropoietin) I.V. or S.C. inj. 25-100 U/kg s.c. or i.v. 3 times a week (max. 600 U/kg/week)
If alcohol is the cause of anaemia, then in addition to taking vitamins and maintaining adequate nutrition, alcohol consumption needs to be stopped.