Case 23 - Glomerulonephritis And Polycystic Kidneys Flashcards
What are the main differences between nephrotic and nephritic syndrome?
Nephrotic - due to a loss of podocytes, leads to loss of protein and albumin (proteinuria, hypoalbuminaemia, oedema)
Nephritic - due to the formation of immune complexes in the glomeruli, leads to a loss of blood and protein (haemturia, proteinuria, oliguria, low GFR, hypertension)
What are the typical features of nephrotic syndrome?
Proteinuria
Hypoalbuminaemia
Odema
Hyperlipidema
What are the complications of nephrotic syndrome?
Thromboembolism (DVT, PE) - this is due to the loss of antithrombin III in the kidneys, resulting in hypercoagulation of the renal vein which could lead to renal vein thrombosis
Hyperlipidemia - low serum albumin causes the liver to componsate and produce more albumin, which has a side effect of lipid production
What are the main features of nephritic syndrome?
Haematuria Proteinuria (small amounts) Oliguira Low GFR Hypertension
What are the primary causes of nephrotic syndrome?
Minimal change disease
Focal segmental glomerulosclerosis (FSGS) - scaring in glomerulus
Membranous glomerulonephritis - immune deposits on basement membrane
Mesangiocapillary GN (MCGN) - immune deposits on basement membrane and mesangial cells
What are the secondary causes of nephrotic syndrome?
Diabetic nephropathy
Hepatitis B/C - can cause membranous nephropathy or MCGN
Lupus
NSAIDS
How is nephrotic syndrome managed?
Furosemide to reduce oema
Fluid and salt restriction
ACEi/ARB - this help to reduce protein loss as they are renoprotective
Anticoagulants - to avoid PE/DVT risk caused by loss of antithrombin III
Ultimately - treat underlying cause e/g, hepatitis, systemic disease
What is the most common cause of glomerulonephritis?
IgA nephropathy
How is IgA nephropathy diagnosed?
Renal biopsy - finds IgA deposits in the mesangial cells
What is the pathophysiology of IgA nephropathy?
Increased IgA due to infection
IgA forms immune complexes and deposits in mesangial cells
Resulting inflammation causes glomerulonephritis
Damage to the filtration mechanism allows blood and protein to enter the urine
What is henoch-schonlein purpura?
It is a systemic varient of IgA nephropathy, causing small vessel vasculitis
More common in children
How is IgA nephropathy treated?
ACEi
What are the common secondary causes of glomerulonephritis?
Post Streptococcal GN
SLE (systemic lupus erthymatous)
Vasculitis
What is the most common causing bacteria that causes poststreptococcal glomerulonephritis and how does it do so?
Group A beta haemolytic streptococci
They carry M protein virulence factor which is considered to be nephritogenic
Streptococcal antigen is deposited on the glomerulus, causing type III hypersensitivity reaction and immune complex formation
What is rapidly progressive glomerulonephritis?
The most aggressive form of nephritic syndrome
Also known as crescentic glomerulonephritis due to crescent shaped cell proliferation that occurs during inflammation
Over time this crescent shape undergoes sclerosis and scaring
This causes damage to the filtration system
What are the causes of rapidly progressive glomerulonephritis?
Anti-GBM disease (goodpastures disease)
Immune complex disease (IgA, SLE, post streptococcal glomerulonephritis)
Pauci immune disease (vasculitis)(ANCA (anti neutrophilic cytoplasmic antibodies))
What are the indications for renal biopsy?
Unexplained acute kidney injury
Chronic kidney diseae
Acute nephritic syndrome
Unexplained proteinuria and haematuria
What is the difference between autosomal dominant polycystic kidney disease (ADPKD) and autosomal recessive Polycystic kidney disease (ARPKD)
ADPKD - presents with ESRF at the age of 60
ARPKD - presents in neonates/childhood
What is the genetic pathology of ADPKD?
Mutations in PKD1 or PKD2
These genes act to inhibit cell proliferation
When they are absent then cells proliferate and express proteins that transport water into the lumen of the cyst
What are the extra renal manifestations of polycystic kidney disease?
Liver cysts
Ovarian cysts
Intra-cranial aneurysms (berry aneurysms) - these can rupture causing a sub arachnoid haemorrhage
Diverticular disease
What are the differentials for autosomal dominant polycystic kidney disease?
Acquired cystic kidney disease
Simple cyst
Tuberous culpritis complex
Von hippal-lindau syndrome
What is the management of autosomal dominant polycystic kidney disease?
Monitor U&E and kidney size Aggressive BP control - ACEi are best Painkillers (but avoid NSAIDS as can be nephrotoxic) Kidney stone treatment Treat any cystic infections Transplantation for ESRF
Why do you get increased BP in renal disease?
Renal diseases result in inappropriate retention of salt and water, leading to hypertension
What blood tests would you do to investigate for a renal glomerular disease?
FBC, ESR, CRP
Renal profile - U&E, eGFR, Creatinine
Bone profile - calcium, phosphate, magnesium
HbA1c
Albumin
Myeloma screen
Hepatitis screen
