Haemolysis Flashcards

1
Q

What causes warm autoimmune hemolysis?

A

(1) IgG autoantibodies

(2) idiopathic

(3) linked to SLE, CLL, drugs, and infections.

(4) Occurs at ≥ 37°C.

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

Define Haemolysis

hola

A

Premature red cell destruction, can result in anaemia

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

What causes cold autoimmune hemolysis?

A

(1) IgM autoantibodies

(2) linked to infections (EBV, mycoplasma).

(3) Occurs at 0-10°C

(4) can angulate, cause holes in cell (MAC)

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

What causes alloimmune hemolysis?

A

The immune system attacks transfused red blood cells

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

What causes hemolytic transfusion reactions?

A

(1) Immediate (IgM) intravascular
(2) Delayed (IgG) extravascular

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

What is the hemolytic disease of the newborn?

A

Due to Rh or ABO incompatibility, or anti-Kell antibodies

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

What causes mechanical red cell destruction?

A

(1) DIC - Disseminated Intravascular Coagulation

(2) HUS - Hemolytic Uremic Syndrome

(3) TTP - Thrombotic Thrombocytopenic Purpura

(4) leaking heart valves
(5) malaria
(6) burns that physically damage red blood cells

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

What causes hereditary spherocytosis?

A

A genetic defect causes RBCs to be sphere-shaped instead of biconcave.

= Results in jaundice, and splenomegaly, and can lead to aplastic crises due to parvovirus B19 infection

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

What is G6PD deficiency?

A

X-linked condition causing hemolysis triggered by infection, drugs, or fava beans.

More common in Mediterranean/Middle Eastern populations

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

Why are RBCs particularly susceptible to damage?

A

Biconcave shape, lack of nucleus, limited metabolic reserve

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

What is compensated hemolysis?

A

Increased RBC destruction is matched by increased production, maintaining Hb levels

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

What is decompensated hemolysis?

A

RBC destruction exceeds bone marrow production, leading to low Hb levels

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

What are the consequences of hemolysis?

A

(1) Reticulocytosis
(2) Erythroid hyperplasia
(3) Excess bilirubin (jaundice, gallstones)

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

What happens in extravascular hemolysis?

A

RBCs are destroyed by spleen/liver macrophages

= Leads to jaundice and splenomegaly

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

What happens in intravascular hemolysis?

A

RBCs burst in circulation, releasing haemoglobin,

= Leads to hemoglobinemia and hemoglobinuria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the clinical features of hemolysis?

A

jaundice, dark urine (hemoglobinuria), fatigue

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

What tests confirm hemolysis?

A

(1) FBC
(2) Reticulocyte count
(3) Unconjugated bilirubin
(4) Blood film (spherocytes, Heinz bodies)
(5) Direct Coombs’ test

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

What does raised lactate dehydrogenase (LDH) indicate?

A

It suggests red cell destruction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How is hemolysis treated?

A

Corticosteroids for autoimmune

IV fluids for transfusion reactions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

The first-line treatment for warm autoimmune haemolytic anaemia is what?

A

steroids

20
Q

Second-line treatment for hemolysis is what?

A

Immunosuppressives and splenectomy

21
Q

If the Coombs test was negative what disease does this rule out and why?

A

Autoimmune haemolytic anaemia

= Coombs test detects antibodies or complement on the surface of red blood cells. A negative Coombs test indicates that there are no antibodies or complement bound to the red blood cells, which rules out autoimmune hemolysis as the cause of anaemia

22
Q

If no history of travel was mentioned. What haemolytic disease does this rule out?

A

Infection induced haemolytic anaemia

23
Q

A 13-year-old girl of Middle Eastern origin is admitted with jaundice and shortness of breath on exertion. These symptoms have started over the course of the last day. She also complains of dark urine and denies any other symptoms. The patient has a past medical history of gallstones. No drug history or travel history is stated.

On examination, conjunctival pallor and jaundice are noted. She also has henna decorating both of her hands.
The Coomb test was negative. What is the underlying pathology giving rise to this presentation? and why?

A

G6PD haemolytic anaemia

= Given her ethnic origin and the fact that she has had henna tattooing which can trigger haemolytic crises in patients with G6PD, this is the most likely answer

24
Q

A 35-year-old man with Glucose-6-phosphate deficiency (G6PD) wants to go on holiday to Nigeria.

What medication should be avoided for malaria prophylaxis?

A

Primaquine

25
Q

Heinz bodies and bite cells on the blood film suggest what

A

oxidative damage to red blood cells, which are common in conditions like G6PD deficiency

26
Q

The patient’s history of neonatal jaundice may have been an early sign for what?

A

G6PD deficiency

27
Q

A 59 year old woman is found to have features of extra-vascular haemolysis on investigation for fatigue; with a haemoglobin concentration of 88 g/L (normal range 115-150 g/L), unconjugated hyperbilirubinaemia of 46 mmol/L (normal <17), and splenomegaly on examination.

The blood count is otherwise normal, and her blood film shows spherocytes and reticulocytosis, and no evidence of intracellular parasites or red cell fragments. There is no social, travel or family history of relevance.

What is the single most appropriate next step?

A

Coombs’ test (direct antigen test)

28
Q

A 32-year-old male from northern Europe attends the GP for his annual influenza vaccine and 5-yearly pneumovax booster.

He is new to the practice and informs the GP that he had a splenectomy when he was 4 years old for recurrent haemolytic episodes. He is unable to remember the name of the underlying disease. He also explains that there is a prominent family history of similar issues: his father, and two of his three daughters are affected, but his wife is unaffected.

On examination, the GP notes a splenectomy scar, but no other findings. What is the single most likely underlying diagnosis?

A

Hereditary spherocytosis

29
Q

What are the triggers for glucose-6-phosphatase (G6PD) deficiency?

A

(1) Intercurrent illness or infection

(2) Fava beans

(3) Henna

(4) Medications: primaquine, sulfa-drugs (such as sulfamethoxazole), nitrofurantoin, quinolones, dapsone and NSAIDs/Aspirin

30
Q

A 70-year-old male presents to the general practitioner complaining of a three-month history of his hands and feet changing colour to dark red. This only happens when he is exposed to cold temperatures and is painful. He also reports a gradual onset of increasing fatigue and breathlessness. His past medical history includes chronic lymphocytic leukaemia. Blood tests show haemoglobin 86 g/l (normal range 135-180g/l), reticulocytes 3.4% (normal range 0.5-1.5%) and a positive Coombs test.

Given the likely diagnosis, which immunoglobulin is most likely involved? and explain why.

A

IgM

Cold autoimmune haemolytic anaemia, which occurs at temperatures around 0-10 degrees, is caused by IgM autoantibodies

IgG antibodies are seen in warm autoimmune haemolytic anaemia

31
Q

What are the first line investigation of chronic lymphocytic leukaemia?

A

Flow cytometry of peripheral blood

32
Q

A 33-year-old female presents to the GP with fatigue and dyspnoea on exertion. Investigations reveal a normocytic anaemia, reticulocytosis and positive Direct Antiglobulin Test (DAT). Her past medical history includes systemic lupus erythematosus and asthma. She regularly takes beclomethasone 200mcg BD inhaler and the oral contraceptive pill.

What would accurately describe the mechanism of the likely diagnosis?

A

IgG-mediated extravascular haemolytic disease

= given her history of systemic lupus erythematosus (SLE), warm autoimmune haemolytic anaemia is the most likely diagnosis

33
Q

What are the causes of warm AIHA?

A

(1) SLE
(2) Idiopathic
(3) Lymphoproliferative neoplasms (eg. chronic lymphocytic leukaemia and lymphoma)
(4) Drugs (methyldopa)

34
Q

What are the causes of cold AIHA?

A

(1) Post-infectious (usually after Mycoplasma or EBV)
(2) Idiopathic
(3) Lymphoproliferative disorders

35
Q

Describe the difference in treatment for warm and cold AIHA

A

Warm AIHA is managed with prednisolone or immunosuppression (e.g. AZT) and transfusions if severe

whereas

Cold AIHA treatment is mostly supportive, warmed blood is transfused if required and resistant cases may trial rituximab

36
Q

Is schistocytes a feature in autoimmune haemolysis?

A

nope

37
Q

Symptoms: fatigue, jaundice, and splenomegaly. What haemolytic disease does this suggest?

A

Hot AIHA

38
Q

Decreased reticulocyte count in those with Haemolytic anaemia. Is this correct?

A

No, Haemolytic anaemia leads to increased reticulocyte count

39
Q

What haemolytic disease are Heinz bodies and bite cells present and seen on blood film?

A

G6PD deficiency

40
Q

Haemolytic uraemic syndrome (HUS) often is caused by what?

A

E. coli 0157

41
Q

What haemolytic diseases show spherocytes and explain the difference

A

Hereditary spherocytosis: Negative Coombs test, positive EMA binding test.

AIHA: Positive Coombs test (direct antiglobulin test)

42
Q

What is the genetic inheritance pattern of hereditary spherocytosis?

A

Autosomal dominant

43
Q

What Is Hereditary Haemolytic Anaemia?

A

Includes conditions like sickle cell disease, thalassemias, and hereditary spherocytosis, often caused by genetic mutations affecting RBC structure or function

(eg, Defect in erythrocyte cell membrane)

44
Q

Common triggers of DIC include what?

A

(1) sepsis, trauma, malignancy, and obstetric complications

(2) bleeding, bruising at venepuncture sites, hypotension and tachycardia

45
Q

What are the typical lab findings in DIC?

A

(1) Prolonged Prothrombin Time/ Activated Partial Thromboplastin Time

(2) Thrombocytopenia
(3) Low fibrinogen
(4) Elevated D-dimer

46
Q

What haemolytic disease would you find Schistocytes?

A

Microangiopathic haemolytic anaemias (MAHA)

(eg)
1. Thrombotic thrombocytopenic purpura (TTP)
2. Haemolytic uraemic syndrome (HUS) 3. Disseminated intravascular coagulation (DIC

47
Q

Describe the difference between spherocytes and schistocytes

A

(1) Spherocytes
= Small, round, dense red blood cells with no central pallor; formed due to membrane loss
(eg, in AIHA or hereditary spherocytosis)

(2) Schistocytes
= Irregular, fragmented red blood cells; formed due to mechanical damage
(eg, in MAHA, TTP, or DIC)

48
Q

What does haemolytic anaemia usually present with? - lab findings

A

(1) Normocytic
(2) Elevated reticulocyte count
(3) unconjugated hyperbilirubinaemia
(4) Raised LDH