Glomerular Disease Flashcards
What does glomerular inflammation lead to?
Blood and protein in the urine (normally should leave protein and blood in glomerular capillaries)
How can complement affect glomerular pathology?
Complement consumption can affect glomerular pathology
Describe the effects of immune complexes
- Promote activation and deposition of complement, opsonisation and phagocytosis
- They can either circulate and cause problems in organs in which they are deposited or form in situ
Which diseases have immune complex deposition as a key feature?
SLE an cryoglobulinaemia (autoimmune diseases)
What is glomerulonephritis?
- Glomerular inflammation generally cause by immunological injury to the glomeruli
What is primary glomerulonephritis?
Antibody targeted to a specific part of the glomerulus e.g. membranous
What is secondary glomerulonephritis?
Glomerulonephritis as part of a generalised disease e.g. SLE
Describe the pathogenic mechanism of glomerulonephritis
- Deposition of circulating or in situ formation of immune complexes
- OR deposition of antiglomerular basement membrane antibodies
- These mechanisms activate secondary mechanisms that lead to the glomerular image and inflammation
- Pattern of injury and clinical presentation will depend on the ‘target’ of the immune response
What are different ways that glomerular disease can present?
1) (Incidental) hypertension
2) Incidental finding of microscopic haematuria
3) Incidental finding of proteinuria
4) Nephrotic syndrome
5) Progressive renal impairment
6) AKI
What questions would you ask in the history to find out about glomerular disease?
1) Any history of diabetes, lupus, other systemic illness, hormonal, structural causes e.g. congenital deformities e.g. aortal co-optation esp. in young patients
2) Any rashes or joint pains?
3) Drug history- recent changes, some can be associated with onset of nephrotic syndrome
4) Systemic symptoms? e.g. fever, haemoptysis
5) Recent angiography?
What might you see on examination of someone with suspected glomerular disease?
- Renal bruits
- Rashes or evidence of active joint inflammation
What investigations might you do in someone with suspected glomerular disease?
1) Bloods - U&E, FBC, CRP, albumin, bone profile, LFT, blood culture
2) C3/C4 complement levels - might be low in SLE
3) Myeloma screen -immunoglobulins, protein electrophoresis (blood and urine) and urine Bence-Jones proteins
4) Virology - Hep B/C and HIV associated with nephrotic syndrome
5) RF
6) ANA, dsDNA, ANCA, anti-GBM
7) Urine dipstick
8) Urine PCR or 24h urine collection for protein
9) Cholesterol - tends to be high in nephrotic syndrome
10) Consider cryoglobulins (if have vasculitic rash)
What imaging would you do in someone with suspected glomerular disease?
- Renal ultrasound esp. if confirmed blood, urine or renal symptoms
- Patients with nephrotic syndrome often have AKI and risk of renal vein thrombosis so check for this on US early
What are other causes of secondary hypertension other than glomerular disease that should be considered?
- Endocrine causes
- Renal artery stenosis
- Hypertension itself can cause blood in urine and glomerular pathology
What are non-glomerular causes of microscopic haematuria esp. in older men and women?
1) Bladder tumours
2) Renal stones
3) Renal tumours
4) BPH
5) UTI
6) Renal injury
What are primary glomerular causes of microscopic haematuria (glomerular inflammation making it leaky)?
1) IgA nephropathy
2) Alports - genetic abnormalities of collagen, X linked but does occur in females, associated with deafness, FH
3) Thin BM disease
4) Post infectious glomerulonephritis
5) Membranoproliferative glomerulonephritis
What investigation results would indicate membranoproliferative glomerulonephritis?
- Low complement levels
- Maybe RF positive
What are secondary glomerular causes of microscopic haematuria?
1) Henoch Scorlein Purpura
2) SLE
3) HUS (more acute presentation)
4) ANCA associated vasculitis
5) Sickle nephropathy
What is ANCA associated vasculitis usually associated with?
Decline in renal function
What is the cause of IgA nephropathy?
- Glomerular deposition of IgA causing inflammation within glomeruli
- In situ IgA being deposited bc of antigens in the kidneys
What is the (variable) clinical presentation of IgA nephropathy?
1) Microscopic haematuria
2) Hypertension
3) Slowly progressive renal impairment, progressive renal scarring - CKD/ESRF
4) Rapidly progressive renal impairment (crescentic IgA)
5) Nephrotic range proteinuria - can cause nephrotic syndrome
What investigation results would show IgA nephropathy?
1) Raised serum IgA
2) Renal biopsy - mesangial proliferation with IgA deposition
How would you manage IgA nephropathy?
- Control of BP to prevent further scarring
- Immunosuppression may be beneficial in some cases e.g. steroids with rapidly progressive renal impairment and nephrotic range proteinuria
Describe the features of Henoch Schonlein Purpura (systemic IgA)
- Inflammation of the small blood vessels esp. in kidney, skin and gut
- Depositions of IgA in kidney in similar pattern to IgA nephropathy
- Depositions of IgA in skin leading to skin lesions
- Most common in young children were can get transient illness
- Associated with leucocytoclastic vasculitis rash
- Variable prognosis - some fully recover with resolution of the rash and renal findings, others progress ESRD
What disease should you think of in a young patient with oedema?
Nephrotic syndrome (CV disease unlikely)
What investigation results would you have in nephritic syndrome?
- Urine dipstick - 3+ protein ± haematuria
- Often preserved renal function with low albumin
- High cholesterol