Describe the 2 signal process of T-cell activation from an APC.
T-cell activation requires 2 signals between the T-cells and APC:
Signal 1: T-cell [TCR:peptide:MHC] APC – necessary but not sufficient
Signal 2: T-cell [CD28:B7] APC – activation of T-cell with IL-2 release and T-cell proliferation
What are CTLA-4 receptors?
CTLA-4 receptors are the doppelganger of CD28 in that they bind preferentially to B7 on APC cell and prevent the activation and proliferation of T-cells.
Normal function is to prevent autoimmunity.
Which interleukin is implicated in T-cell proliferation?
IL-2 is released upon activation of T-cell to promote T-cell proliferation
What is polyarteritis nodosa (PAN)? Which sex is it more likely to affect?
Medium vessel vasculitis that affects M > F.
Which organ systems are implicated in polyarteritis nodosa (PAN)? Which organ system that tends NOT to be implicated?
Systemic - fever, malaise, weight loss 80%
Neuropathy - mononeuritis multiplex, polyneuropathy 75%
Arthralgia/myalgia 60%
Skin - livedo reticularis, pupura, ulcers 50%
Renal disease 50%
GI - abdominal pain, rectal bleeding 40%
HTN - new onset 35%
Orchiditis - testicular pain 20%
Lungs tend NOT to be involved.
Which viral illness is polyarteritis nodosa (PAN) associated with?
Hep B
What are the investigations for polyarteritis nodosa (4)?
True/False: complement C3/4 is elevated in polyarteritis nodosa (PAN).
False.
What is the treatment of polyarteritis nodosa (s)?
What are 6 conditions are associated with pANCA (use mnemonic).
My Personal Computer Is Really Good! … So i Permanently ANCHORED it to my desk!
(MPCIRG = pANCA)
Microscopic polyangitis (MPA)
Polyarteritis nodosa (PAN)
Churg-Strauss (EGPA/Eosinophilic GPA)
IBD (esp. UC)
RPGN - Rapidly Progressive Glomerulonephritis (necrotising/cresentic GN)
Goodpasture’s Syndrome (anti-GBM)
What is the new name for Wegener’s Granulomatosis?
GPA (Granulomatosis with PolyAngiitis)
How is GPA (granulomatosis with polyangiitis) diagnosed (biochemistry/immunofluorescence/histopathology/urine)?
Biochem: c-ANCA, PR3
Immunofluorescence: Pauci-immune
Histopathology: necrotising medium vessels + granulomas
Urine: postive urinary sediment
Which organ systems are implicated in GPA (granulomatosis with polyangiitis)?
ELK:
ENT
Lung - PE (20x risk)
Kidney - haematuria/RPGN
What type of glomerular disease is GPA (granulomatosis with polyangiitis) associated with?
Rapidly-progressive GN (RPGN)
True/False: GPA (granulomatosis with polyangiitis) is more likely to relapse than Microscopic Polyangitis?
True.
What is the treatment of GPA (3)?
What is MPA (Microscopic Polyangiitis)?
Necrotising small vessel vasculitis
What Ab-staining occurs in MPA (Microscopic Polyangiitis)?
Easy MPA (word contains MPo + P-anca + Pauci-immune):
How is MPA (Microscopic Polyangiitis) diagnosed (biochemistry/immunofluorescence/histopathology/urine)?
Biochemistry: p-ANCA / MPO
Immunofluorescence: pauci-immune, small % with anti-GBM (Goodpastures)
Histopathology: necrotising small vessels
Urine: positive urinary sediment
What are the points of differentiation between MPA and GPA (biochemistry/immunofluorescence/histopathology/urine)?
Biochem:
GPA = c-ANCA/PRS
MPA = p-ANCA/MPO
Histopathology:
Both are necrotising.
GPA = vasculitis of medium-sized vessels + granulomas
MPA = vasculitis of small-sized vessel with NO granulomas
Immunofluorescence and urine: Same - both pauci-immune and with positive urinary sediment.
Use:
Which is more severely affected in MPA; kidneys or lungs?
MPA: Kidneys > Lungs
‘Malaysia Pacific Airlines flies to Kuala Lumpur’
Glomerulonephritis +/- RPGN»_space; alveolitis / haemoptysis
What is the treatment for MPA (3)?
What is another name for Churg-Strauss?
EGPA (eosinophilic granulomatosis with polyaniitis)
Which HLA is Churg-Strauss/EGPA associated with?
HLA-DRB4