Glomerulonephritis Flashcards
What are some of the pathophysiological mechanisms of glomerulonephritis?
- Antibodies, immune complexes or complement,
- Cell mediated mechanisms,
- Metabolic, genetic or vascular
What are the secondary causes of glomerulonephritis
- Myeloma or CL,
- Diabetes,
- Gastro - IBD or coeliacs
- Resp - Bronchiectasis, lung cancer, TB,
- Infectious diseases - Hepatitis, HIV, malaria,
- Rheumatological - RA, lupus, amyloid,
- Drugs - NSAIDs, bisphosphonates
What is seen in a glomerulonephritis screen?
- ANCA,
- Anti -GBM,
- ANA/ds-DNA,
- Complement,
- Anti-PLA2R,
- Immunoglobulins,
- Rhumatoid factor,
- Virology (hepatitis B/C, HIV)
What are the basic/non basic investigations for suspected glomerulonephritis?
Basic - U+Es, Urinalysis, quantify proteinuria, check albumin and ultrasound.
Non basic - GN screen, kidney biopsy
What can a kidney biopsy show?
- Light microscopy,
- Immunofluorescence,
- Electron microscopy (looks at ultrastructure)
It is the gold standard for diagnosis of GN
What are the possible presentations of glomerulonephritis?
- Incidental finding of urinary abnormalities,
- Visible haematuria,
- Synpharyngitic (sore throat and visible haematuria)
- Nephritic syndrome,
- Nephrotic syndrome,
- Acutely unwell with rapidly progressive glomerulonephritis
What are the features of nephrotic syndrome and the common causes?
- It presents with 3.5g proteinuria per day (PCR >300), low serum albumin (<30) and oedema (due to low albumin) and due to the low albumin the liver attempts to maintain oncotic pressure by increasing synthesis of lipoproteins causing hyperlipidaemia.
- Occurs due to injury to podocytes
- In adults it is commonly caused by membranous glomerulonephritis and in children its minimal change disease.
- NephrOtic syndrome has lots of prOteins
What are the features of Nephritic Syndrome and the common causes?
- Hypertension, haematuria and milder proteinuria which occurs due to breaks in the GBM
- Causes - IgA nephropathy, SLE, post-streptococcal GN
What is IgA nephropathy and its presentation and treatment?
- It is caused by abnormal/excessive production of IgA which gets deposited in the mesangium causing glomerulonephritis. It often presents after a URT infection but can be secondary to other diseases like henoch schonlein purpura.
- It presents with nephritic syndrome (Haematuria, hypertension and proteinuria) but is more of a spectrum as it can cause heavy proteinuria
- Treatment is non specific, treat the hypertension with ACE inhibitors (will also reduce proteinuria)
What are the differences between IgA nephropathy and post-streptococcal GN?
IgA nephropathy occurs 1-2 days post infection where as PSGN occurs weeks after infection.
Renal biopsy will show IgA immune complexes in IgA nephropathy whereas it will show IgG in PSGN.
Explain the presentation and causes of membranous glomerulonephritis
- It is a disease of adults which presents with nephrotic syndrome.
- Primary disease is caused by anti-phospholipase A2 receptor antibodies, this results in immune complexes damaging the basement membrane. Secondary causes are malignancy, infection or drugs which cause immune complexes which deposit in GBM.
What is the treatment of membranous glomerulonephritis?
- Treat underlying disease if it is secondary.
- Give supportive treatment such as ACEi (reduce proteinuria) and diuretics/salt restriction to control oedema
- Immunotherapy with steroids, cyclophosphamide or rituximab
Describe the causes, presentation and treatment of minimal change disease
- It is the commonest form of GN in children. It is a T cell cytokine mediated process which causes foot process fusion and damage to GBM.
- It presents acutely with nephrotic syndrome which may follow an URT infection. Rarely causes renal failure.
- Treated with prednisolone 1mg/Kg for 8 weeks. 50% will relapse.
Explain the cause and presentation of rapidly progressive/ crescentic GN
-It is an aggressive GN characterised by glomerular crescents on kidney biopsy. Can progress to ESRF.
- It can be caused by Goodpasture’s syndrome (anti-GBM), ANCA vasculitis, lupus nephritis, infection associated
- It presents with nephritic syndrome
