The use of intravenous immunoglobulin in intensive care

Question 1

Mechanism of action of immunoglobulins

Answer 1

• Complement activation
• Antibody-dependent cellular cytotoxicity: Ig activates NK cells to degranulate and destroy cells with the protein perforin
• Neutralisation: IgG, IgM, and IgA bind to toxins/ bacteria/ viruses and prevent them from binding to body cells
• Opsonisation: IgG binds to pathogens, phagocytes recognise the IgG and phagocytose the pathogen
• Mast cell activation: IgE causes mast cell degranulation

Question 2

Proposed mechanism of action of IVIg

Answer 2

• Fab receptor binding: suppression of T cells
• Fc receptor binding: ? shortens half-life of native Ig
• Inhibition of B cells: Induction of apoptosis of B cells

Question 3

Adverse reactions to IVIg administration

Answer 3

• Hypotension
• Headache
• MSK pain
• fevers
• Hypersensitivity reaction
• TRALI
• VTE risk
• AKI
• Transmission of BBV

Question 4

Indications for IVIg use in critical care

Answer 4

Neurological Conditions
- Gullain-Barre Syndrome
- Myasthenia Gravis
- Chronic inflammatory demyelinating neuropathy
- Acute disseminated encephalomyelitis

Infectious disease
- Toxic shock syndrome
- C Diff

Haematological conditions
- Vaccine-induced thrombocytopaenia and thrombosis
- Post-transfusion purpura