GN 2.0 Flashcards
what is virtually pathognomic of GN in the urine
red cell cast
nephritic syndrome
- Syndrome comprising signs of nephritis, presents with haematuria, hypertension and oedema (not as severe as that in nephrotic syndrome)
- indicative of a proliferative process affecting the endothelial cells
nephrotic syndrome
- Defined as proteinuria >3g/d, hypoalbuminuria (<25g/L) and oedema with severe hyperlipidaemia (and cholesterol)
- This is indicative of a non-proliferative process affecting podocytes.
how does proteinuria affect BP target
aim for 120/75 rather than 130/80
what is the most common GN in the developed world
IgA nephropathy
IgA nephropathy
- there is raised abnormal IgA, possibly due to infection, which is targeted by the immune system and forms immune complexes (with IgG) which are deposited in mesangial cells
- They accumulate and cause local immune activation (pro-inflammatory cytokines are released and macrophages arrive) and injury. RBC pass through into urine
which systemic condition does IgA Nephropathy overlap with
HSP
typical patient with IgA Nephropathy
- young man with episodic macroscopic haematuria almost immediately after resp/gi infection
- recovery is rapid between attacks
how soon after infection does IgA Nephropathy tend to occur
1-2 days
presentation of IgA Nephropathy
- asymptomatic/intermittent macroscopic/microscopic haematuria ± nephritic syndrome
what is seen on investigation of IgA nephropathy
- LM: diffuse mesangial IgA deposition. Mesangial cell proliferation and expansion
-
IF: immune deposits (IgA and C3) in mesangium
- The finding of complexes that contain IgA can differentiate it from other GN
- EM: electron dense deposits in the mesangium
- normal complement levels
prognosis of IgA nephropathy
25% progress to ESRF n ten years
management of IgA nephropathy
main focus is preventing further damage and avoiding end stage kidney disease
- BP control: ACEi and ARBs/fish oil
- Prevent immune complex formation: corticosteroids
- With nephritic presentation, immunosuppression may slow down decline of renal function
how does post-streptococcal GN present
nephritic syndrome
how common is post-streptococcal
very rare IRL
how long after infection does post-streptococcal present
few weeks
notifiable biochemical markers in post-streptococcal
low complement
what is found in the urine in post-streptococcal
proteinuria (even tho it is associated with nephritic syndrome - remember!)
RPGN
- purely a marker of severeity
- acute deterioration of kidney function, associated with crescent formation
how severe is RPGN
can cause ESRF over a few days
causes of RPGN
Vasculitis e.g. ANCA+:
- Pauci-immune (no anti-GBM, no immune complexes)
- cANCA (GPA) and pANCA (microscopic polyangiitis and eGPA)
Immunological e.g. ANCA-:
- Anti-GBM: Good pastures disease
- Immune complex disease: HSP/IgA, SLE, post-streptoccocal glomerulonephritis
how do crescents form
- seen in RPGN and Goodpasture’s
- Glomerular disease leads to gaps or holes in the GBM resulting in epithelial cell proliferation with mononuclear infiltration in Bowman’s space. Ultimately, crescent is replaced by scar tissue
- Lose ability to filter, can quickly lead to AKI.
- There is active urinary sediment: RBC, RBC and granular casts
clinical presentation of RPGN
- AKI ± systemic features
- There is often an insidious onset, with a long history of general malaise
- General: malaise, fatigue, fevers
- Skin: cutaneous nodules
- Neurological: mononeuritis multiplex
- MSK: myalgia, arthritis
- Eyes: iritis, uveitis
- Respiratory: haemoptysis, SOB
- Other: oral ulceration
what must be done urgently with RPGN
renal biopsy
anti-GBM IF
linear shape
immune complex deposition on IF
granular