Red Blood Cell Disorders

DR.Leni Lismayanti, SpPK-K

Dept of Clinical Pathology RSHS/FKUP Bandung

Reference book:• Denise M Harmening. Clinical

Hematology and Fundamental of Hemostasis. 5th edition. Philadelphia: FA Davis Co, 2009.

RBC Structure & Function• Areas of RBC metabolism important in

normal RBC survival and function: RBC membrane Hb structure & function RBC metabolic pathway

RBC Membrane• RBC membran proteins:

- Deformability

- Permeability

• RBC membran lipids:

- Phospholipd

- Glycolipid

- cholesterol

RBC membrane

Abnormality That Can Lead to a Change in RBC Morphology

Abnormality RBC Morphology

Cholesterol accumulation in the RBC membrane (liver disease)

Target cells

Abetalipoproteinemia with cholesterol accumulation

Acanthocytes

LCAT deficiency with cholesterol accumulation

Hemolysis with RBC fragmentation

Decreased phosphorylated spectrin or altered spectrin

Bite cells and spherocytes

Hb Structure & Function

Hb synhesis

depends on 3 prs:- Adequate Iron

delivery & supply- Adequate synthesis

of protophorphyrin- Adequate globin

synthesis

Hb function: delivery and release of oxygen to the tissue and facilitation of CO2 excretion.

RBC Metabolic PathwayATP needs for:

• Hb function

• Membrane integrity & deformability

• RBC volume

• Adequate amounts of reduced pyridine nucleotides

• Protection of metabolic enzymes

RBC Senescence & Hemolysis• RBC traveles 200-300 miles during 120

day life span undergo the process of senescence (aging) metabolic & physical changes.

• 1% RBC taken out (removed) from circulation by RES/MPS process:

- Extravascular hemolysis (90%)

- Intravascular hemolysis (5-10%)

Extravascular Hemolysis

Any questions?

RBC Disorders:

1. Numbers:• Decreased (Anemia)• Increased (Polycythemia)

2. Structure and function:• Hemoglobin• RBC membrane• Abnormal erythropoiesis nutritional

RBC disorders morphologic changes

Anemia• Inability of the circulating blood pool to

supply the tissue with adequate oxygen for proper metabolic function.

• Clinically d/ based on: HT, SS, PE, Lab.• Caused by or associated with underlying

disease.• Usually associated with decrease Hb &

Hct (Lab: + RBC count).• Consideration by age, sex and other fact

Classification of Anemia• Based on Hb level:

• Moderate (7-10), severe (<7).

• BM dynamic:

• Hypoproliferative

• Accelerated destruction

• combination

• Clinically (caused):

• RBC indices (normochromic normocytic)

Categories of anemia by causes1. Blood loss

2. Accelerated destruction

3. Nutritional deficiency

4. BM replacement

5. Infection

6. Toxicity

7. Hematopoietic SC arrest/damage

8. Hereditary/acquired defect

9. idiopathic

Significance of Anemia and Compensatory Mechanism

• N: 1% of RBC loss daily BM produce (measured by reticulocyte count 0.5-2.0%).

• Replacement RBC requires:

1. Adequate functioning SC in BM

2. Normal RBC maturation process

3. Ability to release mature RBC from BM

• Proper HB & RBC production requires:

1. Variety of nutritional factors

2. Normal pathway of Bh synthesis

• In severe anemias symptoms of functional impairment of several organs (+).

• Compensatory mechanism increase 2,3-DPG levels

2,3-DPG• Physiologic regulator of:

1. Normal Hb oxygen-carrying capacity

2. Tissue oxygen delivery

• 2,3-DPG (+) Hb more readily released oxygen to tissues depend on: pH & Oxygen level of arterial blood.

• N individual responds to anemia elevated EPO Recombinant EPO Th/ certain anemia.

Lab Tests in Diagnosis of Anemia

• Hb

• Hct

• (RBC Count)

• RBC indices

• Peripheral Blood Smear

• Reticulocyte Count

• BM smear/biopsy

Treatment of anemia: depends on etiology

Polycythemia1. Polycythemia Vera (Myeloproliferative

disorders).

2. Secondary Hypoxic Polycythemia (Secondary Erythrocytosis).

3. Relative Erythrocytosis.

Manifestations PV SE RE

CLINICAL FEATURES

Cyanosis Absent Present Maybe present

Heart/lung disease Absent Present Absent

Splenomegaly Present in 75% Absent Absent

Hepatomegaly Present in 35% Absent Absent

LAB FEATURES

RBC mass Increased Increased Normal

EPO Decreased (rarely N) Increased (rarely N) Normal

Arterial O2 saturation Normal Decreased Normal

WBC count Increased in 80% Normal Normal

Platelet count Increased in 50% Normal Normal

NRBCs poikilocytes Often present Absent Absent

LAP Increased in 70% Normal Normal

BM Hypercell; eryth & myelop ↑; Erythropoiesis ↑ Normal

Megakaryocytes ↑; fibrosis

Serum vit B12 Increased in 75% Normal Normal

Culture studies Autonomous, ery proliferation EPO dep.col.form Not applicable

Any questions?

RBC MorphologyRBC Morphology

Thank You Very Much for Your Attention