Kidney & systemic disease Flashcards
List the main multi-system diseases which involve the kidney
Diabetes Vasculitis' Renovascular disease Myeloma Lupus
Which type of diabetes can lead to diabetic nephropathy?
Type 1 AND type 2
How can we diagnose overt diabetic nephropathy?
Persistent albuminuria >300mg on two separate occasions at least 3-6months apart
Explain the pathogenesis of diabetic nephropathy
Glucose causes the release of vasoactive mediators which dilate the afferent arterioles of the kidney –>
Increased blood flow and thus GFR –>
Glucose stimulates growth factors causing kidney hypertrophy –>
Mesangeal expansion –>
Nodule formation (diabetic glomerulosclerosis) –>
Inflammation –>
Proteinuria (podocyte dysfunction) –>
Tubulo interstitial fibrosis
What do we call the nodules found within the kidney because of diabetes?
Kimmelstiel Wilson lesions
How long does diabetic nephropathy take to develop?
Roughly 15-20 years
How is diabetic nephropathy diagnosed?
Proteinuria
Other diabetic complications
Renal impairment
How is diabetic nephropathy managed?
Glycaemic control (HbA1c
How do ACE/ARBs help in diabetic nephropathy?
Dilate efferent arterioles in the kidney
What renal replacement therapies are available to diabetic patients?
Dialysis
Kidney +/- pancreas transplant
Who cannot get a combined kidney and pancreas transplant?
Type 2 diabetics
Define renovascular hypertension
Secondary hypertension usually caused by renal artery stenosis
What are the two main causes of renovascular disease? Which age groups get each?
Fibromuscular dysplasia (young) Artherosclerotic (old)
How does renal artery stenosis cause renovascular hypertension?
Hormonal and neuronal mechanisms increase blood pressure in response to reduced renal perfusion
Define ischaemic nephropathy
Reduced GFR associated with reduced renal blood flow beyond homeostatic correction
How does ischaemic nephropathy progress?
Renal atrophy then CKD
Which patients tend to get fibromuscular dysplasia?
Young women 15-50 y/o
In which case might you expect fibromuscular dysplasia to affect both renal arteries?
Familial fibromuscular dysplasia
List two conditions associated with fibromuscular dysplasia
Marfan’s syndrome
Ehlers Dantos
Which other important arteries, apart from the renal, can be affected in fibromuscular dysplasia?
Carotid (i.e carotid artery dissection)
Which patients tend to get artherosclerotic renal disease?
Old white men with CVS risk factors
How does renovascular disease present clinically?
Hypertension AKI after hypertension treatment (ACE/ARB) CKD in elderly with vascular disease Sudden onset pulmonary oedema Microscopic haematuria Background arterial disease
What examination finding may be present in a patient with renovascular disease?
Abdominal bruit
How can ischaemic nephropathy be diagnosed?
USS
Artery duplex scans
CT/MR angiography
Angiogram
What is the characteristic radiological sign of fibromuscular dysplasia?
Corkscrewing of the arteries
How is renovascular disease managed?
BP control
Angioplasty +/- stenting
Which blood pressure drugs should not be given in renal artery stenosis? Which other condition should these drugs not be given in?
ACE/ARB
Fibromuscular dysplasia
What is multiple myeloma?
Cancer of plasma cells (i.e antibody producing cells)
Where do abnormal plasma cells collect in multiple myeloma? What do they interfere with?
Bone marrow
Red blood cell production
What is it that gets produced in multiple myeloma which damages the kidneys?
Paraprotein
How does multiple myeloma present?
Bone pain Weakness Fatigue Weight loss Hypercalcaemia Renal failure** Amyloidosis Recurrent infections Anaemia
Who is at most risk of multiple myeloma?
Black people
Old people
Female at a younger age than males
How do renal problems manifest in multiple myeloma?
AKI secondary to hypercalcaemia
Monoclonal immunoglobulin deposition disease
Cast nephropathy
Amyloidosis
What is amyloidosis?
Deposition of proteins in extracellular spaces
How can renal amyloidosis be classified?
Primary (AL) and secondary (AA) amyloid
How does amyloidosis present histologically?
Positive congo red stain
Apple green bifringence under polarised light
Apart from the kidneys where does amyloidosis tend to occur?
Heart
How is AKI due to multiple myeloma managed?
Stop nephrotoxics (NSAIDs, diuretics) Treat hypercalcaemia Avoid contrast Chemotherapy for tumour (+/- dexamethasone) Plasma exchange Dialysis
How is kidney related hypercalcaemia treated?
Fluids
IV pamidronate
Which type of vasculitis affects the kidney the most? Name three of these
Small vessel ANCA
GPA, eGPA, microscopic polyangiitis
Which age group typically gets vasculitis’?
Elderly
How do vasculitis’ present in general?
Constitutional symptoms (fever, arthralgia, weight loss, etc)
Where does GPA most commonly affect?
Respiratory tract
How does GPA present?
Nasal crusting Sinusitis Rhinorrhea Otitis media Ulcers Epistaxis
Which clinical sign may be present in GPA?
Saddle nose (reduced blood supply to cartilage)
How does eGPA present?
Asthma (late onset)
Eosinophilia
Palpable purpura or subcutaneous nodules
Where does eGPA most commonly affect?
Lungs
What do GPA and eGPA have in common histologically?
Necrotising granulomatous inflammation
Are there granulomas in microscopic polyangiitis?
No
Pulmonary haemorrhages can occur in which small vessel vasculitis’? Why?
GPA
eGPA
Microscopic polyangiitis
Alveolar capillary involvement
How are small vessel vasculitis’ diagnosed?
Urinalysis CRP, PV Complement ANCA Biopsy of involved sites
Which ANCAs are associated with the small vessel vasculitis’?
GPA - c-ANCA (cytoplasmic) & PR3
eGPA - p-ANCA (perinuclear) & MPO
Renal involvement is most common in which two small vessel vaculitis’? How does it present?
GPA
Microscopic polyangiitis
Proteinuria
Haematuria
AKI
Biopsy showing segmental necrotising GN
Crescents on renal biopsy are characteristic of what?
Vasculitis
How are vasculitis’ treated?
Immunosuppression (IV methylpred & cyclophosamide) Plasma exchange Renal support (i.e dialysis)
What is the cause of SLE?
No one knows
What systems can be affected in SLE?
Skin Joints Kidneys Lungs Serous membranes Nerves
Which patients most commonly get SLE?
Young woman
African american people
Hispanic people
How might SLE present?
Malar rash Discoid rash Photosensitivity Oral ulcers Non-erosive arthritis Pluropericarditis Renal impairment
Which antibodies are positive in SLE?
Anti-dsDNA
Anti-ANA
Anti-Sm
What is renal disease caused by SLE called? How does it most commonly present?
Lupus nephritis
Proteinuria +/- haematuria
How is lupus nephritis treated?
ACE/ARB
Immunosuppression (high dose steroids + immunosuppressant –> steroids + immunosuppressant)
What are the poor prognostic features of SLE?
Male Renal involvement Extremes of age at presentation Anti-phospholipid syndrome High disease activity
