Type II Hypersensitivity

Question 1

Pathophysiology of haemolytic disease of the newborn

Answer 1

Maternal IgG mediated type II reaction against neonatal erythrocytes → foetal reticulocytosis and anaemia

Question 2

Diagnosis of haemolytic disease of the newborn

Answer 2

DAT +ve

Question 3

Treatment of haemolytic disease of the newborn

Answer 3

Maternal plasma exhange
Exchange transfusion

Question 4

Pathophysiology of autoimmune haemolytic anaemia

Answer 4

Type II autoimmune destruction of RBCs → anaemia

Question 5

Diagnosis of autoimmune haemolytic anaemia

Answer 5

DAT +ve
Anti-RBC Ab

Question 6

Treatment of autoimmune haemolytic anaemia

Answer 6

Steroids

Question 7

What is Evans syndrome?

Answer 7

AIHA + ITP = Evans syndrome

Question 8

ITP pathophysiology

Answer 8

Type II reaction - antibodies against GPIIb/IIIa → bruises (thrombocytopenic), bleeding (purpura)

Question 9

ITP Ix

Answer 9

Anti-platelet antibody

Question 10

ITP Mx

Answer 10

Steroids
IVIG
Anti-D
Splenectomy

Question 11

Goodpasture’s disease pathophysiology

Answer 11

Type II reaction - antibodies attack the non-collagenous domain of basement membrane collagen type IV → glomerulonephritis and pulmonary haemorrhage

Question 12

Goodpasture’s disease Ix

Answer 12

Anti-GBM Ab
Renal biopsy + immunofluorescence - linear smooth IgG deposits on basement membrane

Question 13

Goodpasture’s disease Mx

Answer 13

Steroids + immunosuppression

Question 14

Pemphigus vulgaris pathophysiology

Answer 14

Type II reaction - antibodies against epidermal cadherin → non-tense blistering of the skin and bullae formation

Question 15

Pemphigus vulgaris Ix

Answer 15

Direct Immunofluorescence - IgG deposition

Question 16

Pemphigus vulgaris Mx

Answer 16

Steroids and immunosuppression

Question 17

Graves’ pathophysiology

Answer 17

Type II reaction - immunoglobulin binds to TSH receptor → hyperthyroidism

Question 18

Graves’ Mx

Answer 18

Carbimazole
Propylthiouracil

Question 19

Myasthenia Gravis pathophysiology

Answer 19

Type II reaction - blocking and destruction of AChR by anti-ACh → fatiguable muscle weakness and double vision

Question 20

Myasthenia Gravis Ix

Answer 20

Anti-AChR
EMG
Tensilon test

Question 21

Myasthenia Gravis Mx

Answer 21

Pyridostigmine (AChesterase inhibitor)

Question 22

Pathophysiology of Acute Rheumatic Fever

Answer 22

Type II reaction to M proteins on Group A Strep (pyogenes)

Question 23

Acute Rheumatic Fever Dx

Answer 23

Clinical - Sx = J❤️NES
Jones criteria

Question 24

Acute Rheumatic Fever Mx

Answer 24

Penicillin

Question 25

Pernicious Anaemia pathophysiology

Answer 25

Type II anti-IF inhibition (early) and anti-gastric parietal cell destruction (late) → decreased absorption of B12 → anaemia

Question 26

Pernicious Anaemia Dx

Answer 26

Anti-gastric parietal cell
Anti-IF

Question 27

Pernicious Anaemia Tx

Answer 27

Hydroxycobalamin (B12)

Question 28

eGPA and MPA pathophysiology and difference

Answer 28

Both: pANCA (myeloperoxidase) vasculitides
eGPA - medium and small vessel vasculitis - allergy → asthma → systemic disease
MPA - Pauci-immune necrotising vasculitis - purpura, lived reticularis, multi-organ involvement

Question 29

eGPA and MPA Mx

Answer 29

Both: PAC - Prednisolone, Azathioprine, Cyclophosphamide
MPA - plasmapharesis

Question 30

GPA pathophysiology and Dx

Answer 30

cANCA +ve (proteinase-3) medium and small vessel vasculitis → granulomas, cavitating lung lesions + haemorrhage, sinus problems, crescenteric glomerulonephritis

Question 31

GPA Mx

Answer 31

Steroids, immunosuppression, co-trimox

Question 32

Chronic Urticaria features

Answer 32

Itchy wheals > 6/52