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