Iron deficiency anemia
Tsila Zuckerman
Anemia
Definition : Decreased RBC mass and HB concentrationAnemia is a result of imbalance between between RBC production and destruction Hypo-regenerative anemia is due to decreased RBC production secondary to impaired marrow function or lack of erythropoietin stimulusHyper- regenerative anemia is due to increased peripheral RBC destruction
Each day 0.8% of RBC mass is exchanged by reticulocytes
Normal retic count : 0.5 – 2% or 25 –125x109/l
Corrected retic count:
%retic x patient HCT/45
Iron deficiency anemia
The most common cause of anemia worldwide
Pathogenesis : Imbalance between iron body requirement and reduced iron supply/increased lost
Microcytic Hypochromic Anemia
Characterized by reduced RBC indices : MCV, MCH , MCHC Peripheral blood smear : small (microcytic) and pale (hypochromic) RBCDifferential Diagnosis : Iron deficiency Thalassaemia Sideroblastic anemia Anemia of Chronic disease
Iron stores and transport
Ferritin : main iron storage protein in the RES. Consists of 22 units of apoferritin and iron core. Each subunit binds 4500 atoms of ironHemosiderin : Insoluble iron- protein complex derived from ferritin Transferin : Main iron transport protein in the blood. Normally 1/3 of iron binding sites are saturated
Total iron stores male 1000
female 500mg
Daily iron loss 1mg
Iron absorption
Average western diet contains 10–15 mg iron/day. 5-10% of dietary iron normally absorbed (1-1.5mg)Dietary iron is in the form of : organic iron (heam or protein bound). inorganic iron . Iron absorption occurs in the duodenum
Factors favoring absorption : Heam iron Vitamin C Acids
Iron deficiency anemia
Factors reducing absorption : Inorganic iron Alkalis- antacids Milk Tea Iron excess
Increased iron requirement : Menstruating female,pregnancy,Infants, adolescence
Iron deficiency- clinical features
Symptoms: Fatigue, weakness, palpitations, shortness of breath, headaches, decreased performance status ,aggravation of angina pectoris
Rare symptoms: Dysphagia, PICA syndrome
Signs: pallor of mucous membranes, tachycardia, orthostatic hypotension, functional systolic murmur, glossitis, angular stomatitis, koilonychia
Laboratory workup
CBC: Low HB MCV < 80fl Peripheral blood smear: microcytosis,hypochromiaBody iron status: Serum iron 50-150g/dl Transferrin 300-360 g/dl Ferritin 50-150 g/dl M ,15-50 g/dl F
MCV fl = HCT/RBC X 10
80-93fl
Cause of iron deficiency anemia
Iron deficient diet (elderly, institutionalized, developing countries)Increased iron demands ( pregnancy,growth)Increased Iron loss (GIT, uterine)Malabsorption (post gastrectomy, celiac )Stages of iron deficiency: Iron store depletion Iron deficient erythropoiesis Iron deficiency anemia
IDA Fe def.
Eryth
Fe depli
t
Fe store
sNorm
al
Iron store
s
Iron overload
0 0 +/- 1+ 2-3+ 3-4+ 4+ Fe stores
410 390 360 330-360
33030
300 300 Trasferrin
10 10 20 25 10060
250 250 Ferritin
Treatment of Iron deficiency
Treatment according to severity of anemia and etiology.In adults : GIT workup mandatory.In case of iron loss treat the cause.Oral iron: Ferrous sulfate 325mg x 1-3/d for 3-6 monthParenteral treatment : for patients with malabsorption / oral iron intolerance
Aplastic Anemia
Definition: pancytopenia resulting from defective hematopoiesis.Pathogenesis: stem cell failure due to intrinsic damage to stem cell or an immune reaction against stem cellsEpidemiology: 1000 new cases/year in USA peak incidence: 30 years , more common in Asia
Etiology
Idiopathic 50-60%
Acquired
Congenital
Acquired AA
Drugs: * Dose related mechanism chemotherapy,sulfa, chloramphenicol * Idiosyncratic mechanism chloramphenicol,indometacin,gold RadiationChemicals:benzene,insecticides,hair dyesViral: hepatitis A viruse
AA – Clinical Features
Insidious/acute presentationSymptoms and signs related to Anemia weakness, fatigue, pallor Neutropenia infections Thrombocytopenia purpura,epistaxis,gingival bleeding,GIT bleeding
Diagnosis of AA
CBC : Anemia normocytic/normochromic Reticulocyte count < 1% Thrombocytopenia Leukopenia
Bone marrow : hypocellular marrow
Severe AA : defined by presence of 2 above criteria 1. Neutrophils < 500 2. Platlets < 20,000 3. Reticulocytes < 20,000 / < 1%Super severe AA : Neutrophils < 200Differential Diagnosis: Acute Myeloid Leukemia Myelodysplastic syndrome
Treatment
Supportive Treatment : RBC transfusion Platelet transfusion Aggressive antibiotics Definitive treatment : Immuno suppressive treatment - Anti thymocytic globulin - Cyclosporine Allogeneic stem cell transplantation
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