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Medicine

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Hematology

Question
13 out of 17
 

A 40 years old female presenting with anemia, mild jaundice for 2 years, peripheral smear showing spherocytes, the best investigation to be done is: (AIPG 10, AIIMS Nov. 2011)



A Reticulocyte count
B Osmotic fragility test

C Coombs test
D Bone marrow aspiration

Ans. C

Coombs test

Extra Edge: Causes of HA

Congenital

1. Membrane abnormalities (hereditary spherocytosis, hereditary elliptocytosis, acanthocytosis, stomatocytosis)

2. Hemoglobin abnormalities (thalassanemias, hemoglobin S, C, D)

3. Red cell enzyme defects (G6PD, pyruvate kinase, hexokinase, glutathione reductase deficiency).

Acquired

1. Immune

a. Isoimmune b. Autoimmune

i. Warm antibody type (Ig G)

· Idiopathic, SLE, lymphoma, chronic lymphatic leukemia, ovarian teratoma, Evan’s syndrome, drug – methyl dopa.

ii. Cold antibody type (Ig M)

· Cold hemagglutinin disease, paroxysmal cold hemoglobinuria (PCH), mycoplasma pneumonia, lymphoma, infectious mononucleosis, SLE, viral infections,

2. Drug related

a. Drug adsorbed onto RBC surface: penicillin, cephalosporins

b. Immune complex mediated: sulphonamides, quinidine

c. Alloimmune (antibodies acquired by blood transfusions, or pregnancy, directed against transfused RBCs).

3. Nonimmune

a. Mechanical (artificial valves, burns, march hemoglobinuria)

b. Infection (malaria, Clostridium welchii, bartonellosis) Q

c. Drugs (sulfonamide, snake venom – viper, nitrofurantoin )

d. Dyserythropoietic (paroxysmal nocturnal hemoglobinuria) Q.

e. Shiga toxin–producing Escherichia coli O157:H7, Clostridium perfringens sepsis

4. Investigations

a. Blood film shows polychromasia, macrocytosis, spherocytes (hereditary spherocytosis) Q, elliptocytes, sickles cells (sickle cell anemiaQ), target cells (thalassanemias Q).

b. Direct Coomb’s test: This test identifies red cells coated with antibody and/or complement Q and a positive result usually indicates an immune cause for the haemolysis.

c. Lifespan of RBC: This is determined by chromium labelling and the major site of RBC breakdown may also be identified.

d. Urinary haemosiderin: The presence of this indicates intravascular haemolysis Q.

e. Other tests: Increased serum bilirubin (usually does not exceeds 6 mg%), indicate intravascular hemolysis, increased LDH, decreased haptoglobin and increased urinary urobilinogen suggest hemolytic Q jaundice.

Important Point:

1. Haptoglobin levels that are decreased but do not accompany signs of anemia may indicate liver damage, as the liver is not producing enough haptoglobin to begin with. (AIIMS Nov 09)

2. As haptoglobin is indeed an acute-phase protein, any inflammatory process (infection, extreme stress, burns, major crush injury, allergy, etc.) may increase the levels of plasma haptoglobin.

Mechanical Red Cell Fragmentation Syndrome

Macro angiopathic (Large vessel)

Microangiopathic (Small vessel)

1. Direct Red Cell trauma from an abnormal vascular surface.

a. Prosthetic Heart Valves

b. Synthetic vascular grafts

2. Large vessel disorders that may cause shearing of Erythrocytes

a. Cavernous Hemangioma (Kasabach-Merritt syndrome)

1. Abnormalities in microcirculation that cause turbulent blood flow.

2. DIC 3. TTP 4. HUS

5. Vasculitis (Collagen Vascular Disorders)

6. Malignant hypertension / Eclampsia

7. Disseminated carcinomatosis (Metastasis)

8. Drugs / Radiation

9. Antiphospholipid syndrome

Hematology Flashcard List

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