L4-Iron Deficiency Anemia (IDA) & Biochemical Investigations

Transcription

1 L4-Iron Deficiency Anemia (IDA) & Biochemical Investigations 1 st Year-College of Medicine Hematology Module-Biochemistry Semester II Dr. Basil OM Saleh

2 Objectives Identify stages in development of IDA Define the meaning of IDA and determine its causes (Etiologic) Employ the biochemical investigation and differentiate the best marker in evaluation of IDA.

3 Classification of anemia Causes of anemia -Iron deficiency; blood loss (GIT & Uterine, ). -Chronic Infection & malignant diseases (chronic anemia). -RBC destruction (hemolysis) e.g. G6PD. -B12 and Folic acid deficiencies. MCV -IDA -Thalalssemia Red cells size and their indices -Hb concentration and Hematocrit -MCV, MCH, MCHC. Normal MCV -Hemolytic anemia MCV -B12 -Folat

4 Stages in the development of iron deficiency (ID) Prelatent reduction in iron stores without reduced serum iron levels Hb (N), MCV (N), iron absorption ( ), serum ferritin ( ), bone marrow iron ( ) Latent iron stores are exhausted, but the blood haemoglobin level remains normal Hb (N), MCV (N), TIBC ( ), serum ferritin ( ), bone marrow iron (absent) Iron deficiency anemia - blood haemoglobin concentration falls below the lower limit of normal Hb ( ), MCV ( ), TIBC ( ), serum ferritin ( ), marrow iron (absent)

5 Iron deficiency and iron deficiency anemia The characteristic sequence of events ensues when the total body iron level begins to fall: 1. decreases the iron stores in the macrophages of the liver, spleen and bone marrow 2. increases the amount of free erythrocyte protoporphiryn (FEP) 3. begins the production of microcytic erythrocytes (anisocytosis-size variation, poikilocytosis-shape variation) 4. decreases the blood haemoglobin concentration, production of microcytic hypochromic RBCs. Iron deficiency anemia Definition and etiologic factor Definition: The end result of a long period of negative iron balance

6 Etiologic causes of IDA Decreased iron intake inadequate diet, impaired absorption, gastric surgery, celiac disease increased iron loss gastrointestinal bleeding, haemorrhoids,salicylate ingestion,peptic ulcer,neoplasm,ulcerative colitis excessive menstrual flow,blood donation,disorders of hemostasis increased physiologic requirements for iron infancy, pregnancy, lactation cause unknown (idiopathic hypo chromic anemia)

7 Symptoms of anemia Fatigue Dizziness Headache Palpitation Dyspnea Lethargy Disturbances in menstruation Impaired growth in infancy

8 Symptoms of iron deficiency Irritability Poor attention span ( poor cognition) Lack interest in surroundings Poor work performance (physical activity) Behavioural disturbances Pica Defective structure and function of epithelial tissue; especially affected are the hair, the skin, the nails, the tongue, the mouth, the pharynx and the stomach Increased frequency of infection

9 Koilonychia; brittle, ridged or spoon nails kkp

10 Pica The habitual ingestion of unusual substances earth, clay (geophagia) ice Usually is a manifestation of iron deficiency and is relieved when the deficiency is treated. Clinical features Pallor of skin, lips, nail beds and conjunctival mucosa Nails -flattened, fragile, brittle, koilonychia, spoon-shaped Tongue and mouth glossitis, angular cheilosis (stomatitis) ; fissuring and ulceration of the corner of the mouth Dysphagia; Peterson-Kelly or Plummer-Vinson syndrome (pharyngeal webs)

11 Laboratory findings Haematological Investigations(1) Blood tests erythrocytes hemoglobin level the volume of packed red cells (VPRC) RBC MCV and MCH Hypochromia platelets usually thrombocytosis Biochemical Laboratory findings (2) Iron metabolism tests serum iron concentration total iron-binding capacity TIBC serum ferritin level serum transferrin receptors

12 When ID is developing, the RE stores (hemosiderin and ferritin) become completely depleted before anemia occurs. At an early stage, no clinical abnormalities. Later, patient may develops general symptoms and signs of anemia. In severe case of IDA ridged or spoon nails. The plasma or serum ferritin concentration declines very early in the development of IDA, long before changes are observed in blood Hb concentration, RBC size, TIBC or serum iron concentration. Thus measurement of serum ferritin concentration is used as a very sensitive & specific indicator of IDA that is uncomplicated by other concurrent disease. In anemia of chronic disorders (chronic inflammatory or carcinoma diseases), serum ferritin is normal or raised. In iron overload (hemachromatosis; genetic disease), serum ferritin is increased, but it is not specific.

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14 NOTES Half a liter of whole blood contains approximately 250 mg iron. Increased demands for iron during infancy, adolescence, pregnancy, lactation and in menstruating women. From 3-6 months after delivery, there is a tendency for negative iron balance because of growth. From 6 months, maternal milk + mixed feeding or supplemented formula milk, prevents iron deficiency. In pregnancy, maternal transfer 300 mg iron to the fetus + blood loss at delivery, so increased maternal needed for ironif Hb below 10 gram/dl, therapy is often needed. In normal adult male, inadequate intake or malabsorption of iron is rarely the sole cause of IDA, as it takes 8 years to develop. Gluten-induced enteropathy, partial or total gastroectomy, autoimmune with H.pylori infection may predispose for IDA, Hookworm may aggravate ID. MCV: mean volume, MCH mean corpuscular haemoglobin

15 Summary IDA is the end result of a long period of negative iron balance Decreased iron intake, increased iron loss, and increased physiologic requirements for iron Measurement of serum ferritin concentration is used as a very sensitive indicator of IDA that is uncomplicated by other concurrent disease