S2i: Understand the pharmacology of human immunoglobulin

S2i: Understand the pharmacology of human immunoglobulin

This information is specific for intravenous immunoglobulin, but note there are many others which can be utilised.

Chemical

  • Solution of human plasma protein (in particular IgG antibodies) with a broad spectrum of antibody activity
  • Managed under the national blood arrangement and funded by National Blood Authority
  • Current list of immunoglobulins available from lifeblood:
    • Intravenous immunoglobulin (IVIg)
    • Subcutaneous immunoglobulin (SCIg)
    • Normal human immunoglobulin
    • Specific immunoglobulin (eg: RhD, cytomegalovirus, hepatitis B, tetanus and zoster)

Use

  • Criteria for clinical use of IVIg:
    • Condition which Ig has established therapeutic role
      • Eg: GBS, ITP, Kawasaki disease
    • Condition which Ig has emerging therapeutic role
      • Eg: ADEM, bullous pemphigoid, HLH, TSS
    • Condition which Ig use is in exceptional circumstances only
      • Eg: myocarditis related to COVID 19 vaccination, MS, autoimmune congenital heart block
    • Typically for the use of replacement of antibodies and with autoimmune disorders

Presentation

  • Clear, colourless solution
  • Supplied in glass bottles
  • Prepared from large pools of human plasma collected from thousands of donors
    • Privigen AU (only IVIg made from entirely Australian volunteer donors all others from USA + European volunteer donors)
  • Process:
    • cold ethanol fractionation -> octanoic acid fractionation -> depth filtration -> anion exchange chromatography
  • Prepared solutions:
    • 5g (50ml), 10g (100ml), 20g (200ml) at concentration 10%
  • Tested for:
    • Hepatitis B, C, HIV
    • Occurs via three step process: incubation at pH 4, 20nm nanofiltration and depth filtration
  • Storage:
    • 25 degrees for up to 3 years
    • Do not freeze
    • Protect from light

Dose

  • Given IV only
  • Dose depends on clinical indication
  • Typically based on body weight

Onset

  • Immediate

Duration

  • Variable

MoA

  • Mainly consists of IgG that are present in normal human population
  • Part of adaptive immune system and therefore activity against infectious agents

PD

  • Immune related affects

PK

A

IV only. Must be used immediately after opening bottle

D

Rapidly between plasma and extravascular fluid. Equilibrium reached in 3-5 days

M

By cells in the reticuloendothelial system

E

Adverse Effects

  • Typically occur due to infusion rate rather than product
  • Most likely to occur in first hour of commencing infusion
  • Specific: Haemolytic anaemia, aseptic meningitis syndrome, thromboembolism, acute renal failure, TRALI
  • General: chills, headache, dizziness, fever, vomiting, arthralgia

Special notes

CI

Hypersensitivity to active substance or excipients, IgA deficiency

Comparison table of IVIg

Link to the table lifeblood.com.au

Author: Suzanne Luong