Genitourinary: Part 3 Flashcards
What people are effected by minimal change disease
Boys under 5
What causes minimal change disease
Idiopathic
Atrophy and allergic reactions can trigger nephrotic syndrome
Drugs
What drugs can cause minimal change disease
- NSAIDs
- Lithium
- Antibiotics (CEPHALOSPORIN, RIFAMPICIN)
- Bisphosphonates
- Sulfasalazine
What disease is associated with minimal change disease
Hodgkins lymphoma
Pathophysiology of minimal change disease
NORMAL glomeruli on light microscopy
FUSION of foot processes of the podocytes on electron microscopy due to disrupted podocyte actin cytoskeleton
Immature differentiating CD35 stem cells are responsible
Clinical presentation of of minimal change disease
- Proteinuria
- Periorbital oedema
- Fatigue
- Frothy urine
Diagnosis of minimal change disease
- BIOPSY:
- normal under light microscopy
- Electron microscopy shows FUSED PODOCYTE FOOT PROCESSES
How is minimal change disease treated
- PREDNISOLONE (reverses proteinuria)
2. CYCLOPHOSPHAMIDE or CYCLOSPORIN for relapses
What can cause asymptomatic urinary abnormalities
- IgA nephropathy
2. Thin Membrane disease
How is IgA nephropathy treated
RAMIPRIL and CYCLOPHOSPHAMIDE
What is thin membrane disease
More likely to leak blood into urine
Define CKD
Long standing, progressive, impairment in renal function for more than 3 months
GFR threshold for CKD
GFR < 60mL/min/1.73 M^2 for more than 3 months with/without evidence of kidney damage
What gender is effected in CKD
FEMALES
What GFR threshold defines established renal failure
<15
What can cause CKD
- Diabetes
- Hypertension
- Atheroscloertic renal vascular disease
- Polycystic kidney disease
- Tuberous sclerosis
- Primary glomerulonephritides (IgA nephropathy)
- SLE
- Amyloidosis
- Hypertensive nephrosclerosis (common in black africans)
- Small and medium-sized vessel vasculitis
- Family history of stage 5 CKD or hereditary kidney disease
- Hypercalcaemia
- Neoplasma
- Myeloma
- Idiopathic
Risk factors for CKD
- Diabetes Mellitus
- Hypertension
- Old Age
- CVD
- Renal stones or benign prostatic hyperplasia
- Recurrent UTIs
- SLE
- Proteinuria
- AKI
- Smoking
- African, afro-caribbean or asian origin
- Chronic use of NSAIDs
What can CKD progress to
End-stage kidney disease
Factors effecting speed of decline in CKD
Underlying nephropathy and BP control
What happens in CKD
- Nephrons failed and burden of filtration falls on fewer functioning nephrons
- Functioning nephrons experience increased flow per nephron as blood flow has not changed, and adapt with glomerular hypertrophy and reduced arteriolar resistance
- Increased flow, increased pressure and increased shear stress set in motion a VICIOUS CYCLE of raised intraglomerular capillary pressure and strain which accelerates remnant nephron failure
PROTEINURIA
ROLE OF ANGIOTENSIN II
Produced locally, modulates intraglomerular capillary pressure and GFR, causing vasoconstriction of postglomerular arterioles and increasing the glomerular hydraulic pressure and filtration fraction
How does angiotensin II effect mesangial cells and podocytes
Increases pore size and impairs the size-selective function of the basement membrane for macromolecules - increased proteinuria
What molecules does angiotensin II up regulate
TGF-beta and PAI-1
Result of angiotensin II up regulating TGF-beta
Increases collagen synthesis and epithelial cell transdifferentiation to myofibroblasts that contribute to excessive matrix formation
What is PAI-1
Plasminogen activator inhibitor - 1
Role of PAI-1
Inhibits matrix proteolysis by plasmin - results in accumulation of excessive matrix and scarring in both the glomeruli and interstitium
Clinical presentation of CKD
- Early symptomatic as kidney has a lot of reserve
- Serum urea and creatinine are raised
- Malaise
- Anorexia and weight loss
- Insomnia
- Nocturne and polyuria due to impaired concentrating ability
- Pruritus
- Nausea, vomiting and diarrhoea
- Symptoms due to salt and water retention (PULMONARY OEDEMA or peripheral oedema)
- Amenorrhea in women and erectile dysfunction in men
11.
At what concentration do uraemic symptoms appear
40mmol/L
Complications of CKD
- Anaemia
- Bone disease
- Neurological syndromes
- CVD
- Skin disease
What anaemia occurs in CKD
Normochromic normocytic anaemia due to decreased ERYTHROPOIETIN secretion
What bone diseases are associated with CKD
- Bone pain
- Renal osteodystrophy - osteomalacia, osteoporosis, hyperparathyroidism
- Renal phosphate retention and impaired 1,25(dihydroxy) Vit D production = loss in ca and compensatory PTH = skeletal decalcification leading to bone disease
Neurological effects in CKD
- Autonomic dysfunction = postural hypotension and disturbed GI motility
- Polyneuropathy resulting in peripheral paraesthesiae and weakness
- Advanced uraemia = depressed cerebral function (loss of consciousness) and myoclonic twitching and seizures
What CVD risk are there with CKD
- MI, Cardiac failure, stroke
- Increased frequency of hypertension , hyperlipidaemia and vascular calcification
- Pericarditis and pericardial effusion due to ANAEMIA
- Pericardial friction rub
- Flow murmurs
Skin disease in CKD
- Pruritus due to urea’s nitrogenous waste product
2. Brown discolouration in nails
Differential diagnosis of CKD
AKI
How can i distinguish between AKI and CKD
- Duration of symptoms
- History
- Previous urinalysis
- Normocytic anaemia, small kidneys on ultrasound and presence of renal osteodystrophy = CKD
Diagnosis of CKD
- ECG for high K signs
- Urinalysis
- Urine microscopy
- FBC
- Immunology
- Imaging
Urinalysis in CKD
- Proteinuria
- Haematuria
- Mid-stream urine sample
- Albumin to creatinine ratio OR protein to creatinine ratio
What would be seen in urine microscopy for CKD
- White cells = bacterial UTI
- Eosinophilia = allergic tubulointerstitial nephrotis/cholesterol emboli
- Granular casts - active renal disease
- Red cells = glomerulonephritis
FBC in CKD
- Urea
- Electrolytes
- Bicarbonate
- Creatinine HIGH
- Low eGFR
- Raised alkaline phosphatase due to renal osteodystrophy
- Raised PTH if CKD is in stage 3
- Anaemia
- Fragmented red cells due to haemolysis
- Raised viscosity
What conditions can cause CKD
- Auto-antibody screening for SLE, scleroderma and good pastures
- Hep B, C, HIV and streptococcal antigen tests
What imagine is used to diagnose CKD
- Ultrasound
- CT
- Biopsy
Why is ultrasound used in CKD
- Check renal size and exclude hydronephrosis
Why is CT used in CKD
- Detect stones, retroperitoneal fibrosis and other causes of urinary obstruction
What is retroperitoneal fibrosis
Abnormal formation of tissue occurs behind cavity of perioenium, spreads to tubes that carries urine
3 main areas of treatment to CKD
- Slow deterioration of kidney function
- Reduce CVD risk
- Treat complications (anaemia)
How do we identify and treat reversible causes of CKD
- Relieve obstruction
- Stop nephrotoxic drugs
- Stop smoking and achieve healthy weight to deal with CVD risk
- Tight glucose control in diabetics
How do we limit BP complications of CKD
- ACEI - RAMPRIL
- ARBs (CANESARTAN)
- Diuretics (ORAL BENDROFLUMETHIAZIDE)
- VERAPAMIL (calcium channel blocker)
In diabetes what drugs is given as first line treatment of BP
CANDESARTAN
How is bone disease caused in CKD treated
- monitor PTh levels = restrict dietary phosphate
- Give phosphate binders to decrease absorption
- CALCITRIOL
How is CVD complications caused by CKD treated
SIMVASTATIN
ASPIRIN
How is anaemia treated
Iron/oflate
How is acidosis treated
Sodium Bicarbonaye
How is Oedema treated
Furosemide
What is the best form of renal replacement therapy
Transplantation
Indications for dialysis
- Sympatic uraemia = pericarditis or tamponade
- Hyperkalaemia not controlled by conservative measures
- Severe acids
- Pulmonary oedema not responsive to diuretics
- Tall T waves, flat P waves, broad QRS complex or arrhythmias
- Metabolic acidosis
- Fluid overload resistant to diuretics
How does haemofiltration work
Achieves blood flow using a blood pump to draw and return blood from the lumen of a dual-lumen catheter placed in the jugular, subclavian or femoral vein
Ultrafiltrate is continuously removed from patient combined with simultaneous infusion of replacement solution
Less haemodynamic instability than haemodialysis
How does haemodialysis work
- Blood is passed over a semi-permeable membrane against dialysis fluid flowing in the opposite direction, thus blood always meets a less-concentrated solution
Blood is taken from artery and returned into a vein at atrioventricular fistula
Cons of haemodialysis
Larger solutes of not clear as effectively
Time-consuming
Pros of haemodiyalysis
Allows good clearance of solutes in short periods but requires patient to be haemodynamically stable
IF a patient has an AV fistula how is haemodialysis done
A synthetic graft is used as you don’t need to wait for a vein dilatation
Complications of haemodialysis
- Hypotension/Cramps
- Nausea/headache
- Chest pain
- Fever/rigors
- Infected dialysis catheter
When is peritoneal dialysis used
CKD
How does peritoneal dialysis work
- Uses peritoneum in the abdomen as a membrane which fluids and solutes are exchanged in the blood
When is peritoneal dialysis done
Home at night
Complications of peritoneal dialysis
- Infection (peritonitis)
- Abdo wall herniation
- Intestinal perforation
- Loss of membrane function over time
Complications of RRTs
- MI
- INFECTION
- Amyloid accumulates in long-term dialysis = carpal tunnel syndrome, arthralgia nd fractures
- Malignancy
When do renal cysts become more common
As age advances
When are kidney cysts found
Ultrasound examination
Types of kidney cysts
- Simple cysts - benign
- Polycystic
- Hydronephrosis when ureter blocks
- Dysplasia - when not formed properly
- Medullary sponge - dilatation of collecting ducts
- Acquired cystic disease - medullary uraemia, dialysis cystic
Types of kidney cysts
- Simple cysts - benign
- Polycystic
- Hydronephrosis when ureter blocks
- Dysplasia - when not formed properly
- Medullary sponge - dilatation of collecting ducts
- Acquired cystic disease - medullary uraemia, dialysis cystic
How does congenital renal cysts occur
- Genetic mutation leaves predisposition
- Increased abnormal cell hyper proliferation -> loss of planar polarity -> cysts initiation -> fluid secretion of epithelial cells -> cyst
How long does it take for renal simple cysts to form
Over time
What condition can cause cysts to form
CKD
What drug can cause CKD
Lithium
When is lithium given
Depression
What can cause renal cyst syndrome
Tuberous sclerosis
What is autosomal dominant polycystic kidney disease
Where multiple cysts develop, gradually and progressively thought the kidney eventually resulting in renal enlargement and kidney tissue destruction
When does ADPKD arise
Males in adulthood
Chance of transmission if one parent is effected with ADPKD
50%
In ADPKD, where does genetic mutations occur
Chromosome 16 (85%)
Chromosome 4 (15%)
What gene does PKD1 code for
Plycystin 1 which is involved in cell-cell interactions - regulates tubular and vascular development of kidney
What protein does PKD2 code for
Polycystic 2 which functions as calcium ion channels
What is the role of polycystic complex that occurs in the cilia
Senses flow in tubule
Consequence of disruption of polycystic pathway
Reduced cytoplasmic ca in principal cells of collecting ducts, causes defective ciliary signalling and disorientated cell division = cyst formation
What causes progressive loss of renal function in ADPKD
progressive loss of renal function due to mechanical compression, apoptosis of healthy tissue and reactive fibrosis
What factors contribute to decline of renal function in ADPKD
Growth and size of cyst
Rate of growth
Patients with rapidly growing cysts on MRI lose function more rapidly
Clinical presentation of ADPKD
- Asymptomatic (screening ended) until 20
- Loin pain and haematuria from haemorrhage , cyst infection or stone formation
- Excessive water and salt loss
- Nocturne
- Bilateral kidney enlargement
- Renal colic due to clots
- Hypertension
- Renal stones (uric acid)
- progressive renal failure
1
Extra renal presentation of ADPKD
- Subarachnoid haemorrhage due to berry aneurysm rupture
- Polycystic liver disease
- Pancreatitis
- Mitral valve prolapse
- Ovarian cyst
- Diverticular disease
Differential diagnosis of ADPKD
- Simple cysts
- Autosomal recessive PKD
- Medullary sponge kidney
- Tuberous sclerosis
How is ADPKD diagnosed
- Family history
- BP raised
- ULTRASOUND
Diagnosis classification of ADPKD
- 15-39 yrs > 3 cysts
- 40-59 years < 2 cysts (each kidney
- 60 years > 4 cysts in each kidney
When do you exclude ADPKD
greater than 40 and less than 2 cysts present
When can you not exclude ADPKD by ultrasound
Less than 30 years
How is ADPKD treated
- BP control - RAMIPRIL
- Treat stones + analgesia
- Laparoscopic removal of cyst
- Disease progression monitored by serum creatinine
- Renal replacement therapy for ESRF
- Children and siblings of patients with the disease should be offered screening by renal ultrasound in 20s
- Counselling and support