RBC DISORDERS-1 Flashcards

Covers materials of the 1st and 2nd ppts in the RBC lecture series

1
Q

Hemolytic anemia; jaundice at birth

Splenomegaly

Normocytic anemia with reticulocytosis

PS: Echinocytes

  1. Cause for formation of echinocytes?
  2. Confirmatory test?

Deborah Dalmeida MD

A
  1. Pyruvte kinase deficiency–>chronic lack of ATP–>membrane damage–>echinocytes
  2. RBC enzyme assay

Deborah Dalmeida MD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Young African- American

fever, cough, chest pain, and pulmonary infiltrates; secondary to infection of lungs

Jaundice

Lab: Hematocrit 18%, unconjugated bilirubin elevated

Peripheral smear attached

What is the genetic basis for this condition?

Deborah Dalmeida MD

A

Point mutation in the 6th codon of beta globin leading to replacement of a glutatmate residue with a valine residue

Deborah Dalmeida MD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q
  1. Type of gallstones formed in hereditary spherocytosis
  2. Why do pigmented gallstones form in this condition?

Deborah Dalmeida MD

A
  1. Pigmented gallstones
  2. Caused by increased liver conversion of excess amounts of UCB to water-soluble conjugated bilirubin (CB), which is excreted in the bile. The CB is converted back to UCB in the gallbladder, and the UCB combines with calcium to form black calcium bilirubinate stones.

Deborah Dalmeida MD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Direct/ Indirect Coomb’s?

patient’s red cells are mixed with sera containing antibodies, specific for human immunoglobulin or complement.

Deborah Dalmeida MD

A

Direct Coomb’s test

Deborah Dalmeida MD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How does transit time through microvascular beds affect sickling?

Deborah Dalmeida MD

A

Transit time- spleen, BM and inflamed vascular beds- more sluggish flow areas- most involved in sickling. Vicious cycle of sickling, obstruction, hypoxia, and more sickling.

Deborah Dalmeida MD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

mc enzyme deficiency causing hemolysis

NCNC anemia

See attached peripheral smear

  1. Diagnosis?
  2. What is the trigger for formation of these cells?
  3. What do the inclusions within the RBcs represent?

Deborah Dalmeida MD

A
  1. Glucose-6-Phosphate Dehydrogenase Deficiency
  2. Bite cells are produced in the face of oxidant stress-Infections,Drugs- antimalarials, sulfonamides, fava bean
  3. The inclusions are Heinz bodies- represent the precipitated dentaured Hb

Deborah Dalmeida MD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

MCHC anemia

Increased serum iron

Increased percent saturation

increased serum ferritin

1. Diagnosis?

2. List important causes

Deborah Dalmeida MD

A
  1. Sideroblastic anemia
  2. Chronic alcoholism, decreased pyridoxine, INH therapy, Lead poisoning

Deborah Dalmeida MD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Direct/Indirect Coomb’s ?

Deborah Dalmeida MD

A

Direct Coomb’s

In the direct Coombs test, red blood cells (RBCs) sensitized with IgG antibodies (or C3b, C3d) are agglutinated when Coombs reagent (rabbit anti-IgG antibody) is added to the test tube.

Deborah Dalmeida MD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the major red cell hemoglobin in beta thalassemia major?

Deborah Dalmeida MD

A

HbF

Deborah Dalmeida MD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Identify the missing protein in the area marked ‘’?” in the image attached.

This protein is involved in transporting ferrous iron from the cytoplasm across the basolateral enterocyte membrane

Deborah Dalmeida MD

A

Ferroportin

Deborah Dalmeida MD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Described below is a peripheral smear appearance. Comment on the possible spleen morphology in this condition:

irreversibly sickled cells

reticulocytosis

target cells, which result from red cell dehydration

Howell-Jolly bodies+/-

Deborah Dalmeida MD

A

Splenomegaly–> infarction–>shrinkage –>autosplenectomy

Deborah Dalmeida MD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Enzymes inhibited by lead

Deborah Dalmeida MD

A

Denatures ferrochelatase- inhibits incorporation of iron into protopophyrin; FEP, which is proximal to the enzyme block, is increased.

Denatures ALA dehydrase → ↑δALA

Ribonuclease is denatured- persist in the RBC, resulting in coarse basophilic stippling

Deborah Dalmeida MD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Identify the missing protein in the area marked ‘’?” in the image attached.

This protein is synthesized and released from the liver in response to increases in intrahepatic iron levels.

Deborah Dalmeida MD

A

Hepcidin

Deborah Dalmeida MD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Passage of dark urine in the morning

Pancytopenia

Decreased serum haptoglobin

Increased urinary hemoglobin

What is the underlying pathogenesis of this condition?

Deborah Dalmeida MD

A

The condition described is Paroxysmal Nocturnal Hemoglobinuria

The pathogenesis is intravascular complement mediated lysis due to acquired PIGA mutation

Deborah Dalmeida MD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q
  1. Possible genotypes in beta thalassemia major?
  2. What do the symbols β+ and β0 mean?

Deborah Dalmeida MD

A
  1. β+/β+

β+/β0

β0/β0

  1. β0: absent beta -globin synthesis; β+: reduced but detectable beta globin synthesis

Deborah Dalmeida MD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Cause for aplastic crisis in sickle cell disease?

Deborah Dalmeida MD

A

Parvovirus B19 infection–>transient cessation of erythropoiesis –>worsening of anemia

Deborah Dalmeida MD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Decreased serum iron

Decreased TIBC

Increased serum ferritin

Decreased percent saturation of transferrin

Normal RDW

Deborah Dalmeida MD

A

Anemia of chronic disease

Deborah Dalmeida MD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q
  1. Name one condition where this finding is seen?
  2. What is the mechanism repsonsible for this appearance?

Deborah Dalmeida MD

A
  1. Lead poisoning
  2. Lead denatures ribonuclease leading to persistence of ribosomal RNA which aggregates

Deborah Dalmeida MD

19
Q

Direct/ Indirect Coomb’s ?

patient’s serum is tested for its ability to agglutinate commercially available red cells bearing particular defined antigens

Deborah Dalmeida MD

A

Indirect Coomb’s test

Deborah Dalmeida MD

20
Q

Direct/Indirect Coomb’s ?

Deborah Dalmeida MD

A

Indirect Coomb’S

In the indirect Coombs test, IgG antibodies (e.g., anti-D) in the serum must first bind to blood group type O test RBCs added to the test tube. Addition of Coombs reagent causes the sensitized type O test RBCs to agglutinate, indicating that IgG antibodies are present in the serum

Deborah Dalmeida MD

21
Q

deletion of all four α-globin genes

severe pallor, generalized edema, and massive hepatosplenomegaly

Deborah Dalmeida MD

A

Hydrops fetalis

Deborah Dalmeida MD

22
Q

Decreased serum iron

Increased TIBC

Decreased serum ferritin

Increased RDW

Deborah Dalmeida MD

A

Iron deficiency anemia

Deborah Dalmeida MD

23
Q

Identify the missing protein in the area marked ‘’?” in the image attached.

The form of iron that is in the storage pool

Deborah Dalmeida MD

A

Ferritin

Deborah Dalmeida MD

24
Q

List 2 hematologic conditions where this appearance is seen?

Deborah Dalmeida MD

A

Sickle cell disease

Thalassemia major

Crew cut appearance - Bone resorption and secondary new bone formation due to expansion of the bone marrow

Deborah Dalmeida MD

25
Q

List 3 hematologic conditions where the following cells seen in the attached peripheral smear are seen

Deborah Dalmeida MD

A

Artificial mechanical cardiac valves

thrombotic thrombocytopenic purpura (TTP)

hemolytic-uremic syndrome (HUS)

disseminated intravascular coagulation

Deborah Dalmeida MD

26
Q

Intravascular/ extravascular hemolysis?

  • Anemia
  • Jaundice-UCB
  • Splenomegaly- due to hyperplasia of phagocytes
  • Depleted serum haptoglobin
  • Elevated LDH

Deborah Dalmeida MD

A

extravascular hemolysis

Deborah Dalmeida MD

27
Q

CLINICAL FEATURES OF LEAD POISONING

Deborah Dalmeida MD

A

colicky type of abdominal pain with constipation

Encephalopathy: edema/demyelination

Growth retardation (kids)- deposits in epiphyses

Wrist drop, foot drop, claw hand – adults

Lead line in the gums

Proximal renal tubular acidosis

Deborah Dalmeida MD

28
Q

List the pain/vaso-occlusive crises assoc with Sickle cell disease

Deborah Dalmeida MD

A
  1. hand foot syndrome/ dactylitis
  2. Acute chest syndrome
  3. Priapism
  4. Stroke, Retinopathy, blindness

Deborah Dalmeida MD

29
Q

Intravascular/extravascular hemolysis?

  • Anemia
  • hemoglobinemia
  • Hemoglobinuria
  • Hemosiderinuria
  • Jaundice- UCB
  • Depleted serum haptoglobin
  • Elevated LDH

Deborah Dalmeida MD

A

Intravascular hemolysis

Deborah Dalmeida MD

30
Q

What is β-thalassemia minor or β-thalassemia trait?

Deborah Dalmeida MD

A

Heterozygotes with one β-thalassemia gene and one normal gene (β+/β or β0/β)

Deborah Dalmeida MD

31
Q
  1. Warm/Cold autoantibody?

IgM type

Cleared by the liver

Peripheral smear shows agglutination mainly

2. List 2 conditions where the type of autoantibody described above is encountered

Deborah Dalmeida MD

A
  1. Cold
  2. Mycoplasma, EBV, Lymphoplasmacytic lymphoma

Deborah Dalmeida MD

32
Q

1. Warm/Cold autoantibody?

IgG type

Primarily cleared by the spleen

Spherocytes seen on blood smear

2. List 2 conditions where the type of autoantibody described above is encountered

3. What test is positive?

Deborah Dalmeida MD

A
  1. Warm
  2. SLE, chronic lymphocytic leukemia
  3. DIrect Coomb’s test is positive

Deborah Dalmeida MD

33
Q

Why do sickle cell patients develop a sequestration crisis?

Deborah Dalmeida MD

A

Massive entrapment of sickle RBCs –>rapid splenic enlargement –>hypovolemia, shock

Deborah Dalmeida MD

34
Q

How does interaction of HbS with HbF affect the degree of sickling?

Deborah Dalmeida MD

A

HbF inhibits the polymerization of HbS hence, infants do not become symptomatic until they reach 5 or 6 months of age, when the level of HbF normally falls

Deborah Dalmeida MD

35
Q
  1. Condition resulting from deletion of three α-globin genes.
  2. Possible clinical presentation of this condition

Deborah Dalmeida MD

A
  1. Hemoglobin H Disease
  2. resembles beta thalassemia intermedia. Severe MCHC anemia but may not require regular transfusions

(refer slide 18 of my powerpoint on RBC Disorders-Part 2)

Deborah Dalmeida MD

36
Q

List 1 example under each of the following causes for iron deficiency anemia:

a. blood loss-
b. increased utilization
c. decreased intake
d. decreased absorption
e. intravascular hemolysis

Deborah Dalmeida MD

A

a. blood loss- Peptic ulcer, hookworm, colorectal cancer

b. increased utilization- menorrhagia, pregnancy, lactation, children

c. decreased intake- dietary deficiency

d. decreased absorption- celiac sprue

e. intravascular hemolysis- MAHA, PNH

Deborah Dalmeida MD

37
Q

mc causative orgainsm for osteomyelitis in sickle cell disease patients

Deborah Dalmeida MD

A

Salmonella paratyphi

Deborah Dalmeida MD

38
Q

Cause for the following symptom:

consumption of non-foodstuffs such as clay, mud, ice

Deborah Dalmeida MD

A

Depletion of iron from the central nervous system- known as pica ; assoc with iron deficiency anemia

Deborah Dalmeida MD

39
Q

List 3 characteristic findings on peripheral smear in the hematologic condition described below:

growth retardation

Enlarged and distorted cheekbones and other bony prominences

Hepatosplenomegaly

Electrophoresis: major red cell hemoglobin is HbF

Deborah Dalmeida MD

A
  1. microcytic hypochromic anemia

target cells

elevated retic count but less than expected for the degree of anemia

Deborah Dalmeida MD

40
Q

Anemia

Jaundice

Increased MCHC

Normal MCV

Increased osmotic fragility

PS: shows small, dark-staining red cells lacking the central zone of pallor

1. Diagnosis?

2. What is the intrinsic defect in the RBC membrane?

3. Why do RBCs develop this characteristic shape?

Deborah Dalmeida MD

A
  1. Hereditary Spherocytosis
  2. Spectrin deficiency (most common)
  3. a. Membrane loss occurs with age–>loss of membrane relative to cytoplasm–> forces RBC to assume the smallest diameter for a given volume–>spherical.
    b. Membrane defect –>loss of both potassium and water, –>cellular dehydration–>spherocyte

Deborah Dalmeida MD

41
Q

Special stain for hemosiderin

Deborah Dalmeida MD

A

Prussian blue

Deborah Dalmeida MD

42
Q

What do the blue stained RBCs represent?

Deborah Dalmeida MD

A

Called sideroblasts - iron trapped within mitochondria in developing RBCs

Deborah Dalmeida MD

43
Q

PS: mild MCHC anemia, target cells

Look at the attached electrophoretic pattern

What’s your diagnosis?

(Hint: Slide 16 of my PowerPoint on RBC-2)

Deborah Dalmeida MD

A

beta thalassemia minor

(Look up slide -16 of RBC-Part 2 to compare the electrophoretic patterns of normal individuals versus Beta thalassemia minor and major)

Deborah Dalmeida MD