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