Glomerulonephritis Flashcards
What is Glomerulonephritis?
Glomerulonephritis includes a range of immune-mediated disorders that cause inflammation within the glomerulus and other compartments of the kidney
What is the pathological basis underlying Glomerulonephritis?
Immunological attack by antibody/T-cell upon antigens in glomerulus
-antigens can be primary or secondary (acquired/deposited)
What are the secondary factors causing deposition of antigens?
NSAID HSP
- neoplasm
- SLE
- amyloid
- infection
- diabetes
- Henoch Schonlein Purpura
What is the pathological response to the primary immunological attack in the glomerular capillaries?
Endothelial cell proliferation
Capillary wall necrosis
Glomerulosclerosis
What is the pathological response to the primary immunological attack in the basement membrane?
Thickened membrane –> structural distortion –> increased permeability
What is the pathological response to the primary immunological attack in the tubules?
Deposition of cells in Bowman’s space
What are the three layers of the glomerulus?
Fenestrated capillary epithelium
Basement membrane
Visceral layer (interdigitating podocytes)
What words are used to describe glomerular pathology histologically?
Global = whole glomerulus diseased Segmental = small patches of one glomerulus damaged Diffuse = affects >50% glomeruli Focal = affects <50% glomeruli
How can glomerular damage/glomerulonephritis present?
AKI (if initially severe enough) CKD Asymptomatic haematuria Nephrotic syndrome Nephritic syndrome Rapidly progressive glomerulonephritis
What are the stages of progression of glomerulonephritis?
Asymptomatic dipstick abnormalities
Nephrotic syndrome
Nephritic syndrome
ESRD
What investigations are appropriate in suspected glomerulonephritis?
Bloods (FBC, U&Es, CRP, culture) Urine dip (?infec) MCS (red cells/casts) Urine protein:creatinine ratio Nephritic screen Renal USS + biopsy
Why is urine protein:creatinine ratio used?
More convenient than 24hr urinary protein & equally accurate
What random protein:creatinine ratio would be suggestive of disease?
50-100mg/mmol = significant proteinuria >300mg/mmol = nephrotic range
What are the main pathological processes affecting the glomerulus?
IgA nephropathy (Beurger's disease) Minimal change nephropathy Membranous nephropathy Focal segmental glomerulosclerosis Membranoproliferative GN Post-streptococcal GN HSP Goodpasture's syndrome Systemic vasculitis Rapidly progressive GN
What is IgA nephropathy (Beurger’s disease)?
Lower end of a spectrum ending in HSP
Most common cause of GN in adults
How does IgA nephropathy present?
Mostly affects young males, often after an URTI
Haematuria (macroscopic)
Nephritic syndrome
How should suspected IgA nephropathy be investigated?
Renal biopsy (IgA/C3 deposits)
How should IgA nephropathy be managed?
Supportive
Steroids may slow decline in renal function
-20% progress to ESRD over 20yrs
What is minimal change nephropathy?
Most common cause of GN in children (75%)
Common cause of nephrotic syndrome in adults (20%)
What are the causes of minimal change nephropathy?
NSAID
Allergy
Hodgkin’s lymphoma
How should suspected minimal change nephropathy be investigated?
Light microscopy (normal) Immunofluorescence (negative) Electro-microscopy (fusion of podocyte foot processes)
How should minimal change nephropathy be managed?
Oral steroids
-99% of cases resolve in 4-6wks
-1% of cases progress to ESRD
Cyclosporin
What is membranous nephropathy?
Rare cause of nephrotic syndrome
-80-90% idiopathic
How should membranous nephropathy be investigated?
Renal biopsy (global diffuse GN w/ IgG & C3 deposits)
