Systemic diseases Flashcards
Diabetic Nephropathy
Causes ~20% of ESRF
Advanced / ESRF occurs in 40% of T1 and T2 DM
Pathology of diabetic nephropathy
Diabetic nephropathy describes conglomerate of lesions occurring concurrently.
Hyperglycaemia → renal hyperperfusion → hypertrophy and ↑ renal size
Hypertrophy and metabolic defects inc. ROS production → glomerulosclerosis and nephron loss
Nephron loss → RAS activation → HTN
Clinical effects
Microalbuminuria (30-300mg/d or albumin:creatinine >3) Strong independent RF for CV disease
Progresses to proteinuria (albuminuria >300mg/d)
Diabetic retinopathy usually co-exists and HTN is
common
Screening for diabetic nephropathy
T2DMs should be screened for microalbuminuria 6moly
Histology of diabetic nephropathy
Damage to the glomerular basement membrane allows proteins in the blood to leak through, leading to accumulation in Bowman’s space - called Kimmelstiel–Wilson nodules
Treatment of diabetic nephropathy
Good glycaemic control delays onset and progression
UKPDS: UK Prospective Diabetes Study
DCCT: Diabetes Control and Complications Trial
Control HTN: BP target 130/80
ACEi/ARB: even if normotensive
Stop smoking
Combined kidney pancreas Tx possible in selected pts
Amyloidosis and features
Renal involvement usually caused by AL/AA amyloid Features: Proteinuria Nephrotic syndrome Progressive renal failure
Differentiating features and investigations
Large kidneys on US
Biopsy
Malignancy - direct
Renal infiltration: leukaemia, lymphoma Obstruction: pelvic tumour
Mets
Malignancy - nephrotoxicity
Toxic chemo
Analgesics
Tumour lysis syndrome
Effects of high PTH
High Ca2+
Effects of sarcoidosis
High Ca2+ and TIN
Myeloma pathology
Excess production of monoclonal Ab ± light chains (excreted and detected in 60% as urinary BJP).
Light chains block tubules and have direct toxic effects → ATN.
Myeloma also assoc. ̄c ↑↑Ca2+
Myeloma presentation
ARF / CRF Amyloidosis
Myeloma treatment
Ensure fluid intake of 3L/d to prevent further impairment Dialysis may be required in ARF
RA
NSAIDs → ATN
Penicillamine and gold → membranous GN AA amyloidosis occurs in 15%
SLE pathogenesis and treatment
Involves glomerulus in 40-60% → ARF/CRF
Immune complex deposition → T3 hypersensitivity
Typically membranous GN
Proteinuria and ↑BP common
Rx
Proteinuria: ACEi
Aggressive GN: immunosuppression
Diffuse systemic sclerosis and treatment
Renal crisis: malignant HTN + ARF Commonest cause of death
Rx: ACEi if ↑BP or renal crisis
Reno vascular disease causes
Cause Atherosclerosis in 80% Fibromuscular dysplasia Thromboembolism External mass compression
Presentation of renovascular disease
Presentation
Refractory hypertension
Renal bruits
Worsening renal function after ACEi/ARB
Flash pulmonary oedema (no LV impairment on echo) Other signs of PVD
Investigations of renovascular disease
US + doppler: small kidney + ↓ flow
CT/MR angio
Renal angiography: gold standard
Treatment of renovascular disease
Rx medical CV risk factors Angioplasty and stenting
AVOID ACEi/ARB
Hypertension effects on the kidney
HTN can be both the cause and effect of renal damage.
Renal diseases are commonest causes of 2O HTN
Activation of RAS
Retention of Na and water due to ↓ excretion
What is haemolytic uraemia syndrome
E. coli O157:H7: verotoxin → endothelial dysfunction
Features of HUS
You children eating undercooked meals e.g. burgers.
Bloody diarrhoea and abode pain precedes
1. MAHA
2. Thrombocytopenia
3. Renal failure
Investigation of HUS
Schistocytes, ↓ plats
↓Hb
Normal clotting
Treatment of HUS
Usually resolves spontaneously
Dialysis or plasma exchange may be needed
What is Thrombotic thrombocytopenia pupura (TTP)
Genetic or acquired deficiency of ADAMTS13 → giant vWF multimers
Features of Thrombotic thrombocytopenia pupura (TTP)
Adult females Pentad: Fever CNS signs: confusion, seizures MAHA Thrombocytopenia Renal failure
Investigating TTP
↓ plats
↓Hb
Normal clotting
Treatment of TTP
Plasmapheresis, immunosuppression, splenectomy
