Glomerulonephritis Flashcards
Define
An immunologically mediated inflammation of the renal glomeruli
There are loads of different types of glomerulonephritis with different aetiologies
Some types are caused by the deposition of antigen-antibody complexes in the glomeruli
This leads to inflammation and activation of complement and coagulation cascades
The immune complexes may form within the glomerulus (more common) or be deposited from the circulation
What are the risk factors?
- Bacteria (e.g. Streptococcus viridans, Staphylococci, syphylis)
- Viruses (e.g. HIV, Hep B and C, measles, mumps, EBV)
- Protozoal (e.g. Plasmodium malariae, schistosomiasis, filiaris)
- Inflammatory/Systemic diseases (e.g. SLE, vasculitis, cryoglobulinaemia)
- Drugs (e.g. gold, penicillinamine, NSAIDs, cocaine, heroin, anabolic steroids)
- Metabolic disorders (diabetes, hypertension, thyroiditis)
- Tumour (lung, colorectal, melanoma, Hodgkin’s lymphoma)
- Hereditary disorders
- Deposition disorders
What’s the classification?
Minimal-change Glomerulonephritis
Light microscopy - minimal change
Electron microscopy - loss of epithelial foot process
Membranous Glomerulonephritis
Thickening of glomerular basement membrane (GBM) from immune complex deposition
Associated with Goodpasture’s Syndrome
Membranoproliferative Glomerulonephritis (MPGN) Thickening of GBM Mesangial cell proliferation and interdeposition
Focal segmental glomerulosclerosis
Glomerular scarring
Associated with HIV
Focal segmental proliferative glomerulonephritis
Mesangial and endothelial cell proliferation
Focal = involvement of some glomeruli
Segmental = involvement of parts of individual glomeruli
Diffuse proliferative glomerulonephritis
Same as above but affects ALL glomeruli
IgA Nephropathy
Mesangial cell proliferation
Mesangial IgA and C3 deposits
Crescentic Glomerulonephritis
Crescent formation by macrophages and epithelial cells, which fills up Bowman’s space
Focal Segmental Necrotising Glomerulonephritis
Peripheral capillary loop necrosis (occurs in granulomatosis with polyangiitis, microscopy polyarteritis and other vasculitides)
Often evolves into crescentic glomerulonephritis
Epidemiology
Accounts for 25% of the cases of chronic renal failure
What are the presenting symptoms?
Haematuria Generalised Subcutaneous oedema Oliguria Anorexia History of recent infection Symptoms of uraemia or renal failure (acute and chronic) presence of risk factors
What are the signs?
Hypertension
Proteinuria
Haematuria (especially in IgA nephropathy)
Renal failure
Nephrotic syndrome - consists of a TRIAD of:
Proteinuria > 3.5 g/24 hrs
Low serum albumin < 30 g/L
Oedema
NOTE: due to the hypoalbuminaemia, the liver tries to compensate and increases production of lipids, causing hyperlipidaemia
What’s the difference between nephrotic and nephritic syndrome?
Nephritic syndrome (TRIAD: hypertension + proteinuria + haematuria)
Syndrome comprising of signs of nephritis
Pores in the podocytes are large enough to allow protein AND red blood cells to pass into the urine
MAIN FEATURE: Haematuria
This is in contrast to nephrotic syndrome, which is mainly concerned with proteinuria
There may also be red cell casts in the urine - indicative of glomerular damage
Other features:
Proteinuria
Hypertension
Low urine output (due to decreased renal function)
NOTE: in nephrotic syndrome, only PROTEINS are moving into the urine
What are the 1st investigations?
Bloods
FBC (normocytic normochromic anaemia – systemic disease)
U&Es + creatinine
LFTs (check albumin) – indicate Hep B and C
Lipid profile (normal or hyperlipidaemia)
Complement studies
Antibodies:
ANA
Anti-dsDNA
ANCA
Anti-GBM antibody
Cryoglobulins
Urine
Microscopy - check for red cell casts
Proteinuria, haematuria, leukocytes, dysmorphic RBCs
24 hr collection: creatinine clearance and protein
Imaging
Renal tract ultrasound to exclude other pathology (e.g. obstruction)
Small kidneys or normal
What are some investigations to consider?
Renal Biopsy
For microscopy
Investigations for associated conditions (e.g. HBV, HCV and HIV serology)
