Kidneys in Systemic Disease Flashcards
What systemic diseases affect the kidney? (8 broad headings)
- Diabetes mellitus
- Cardiovascular disease
- Infection
- Inflammation of blood vessels
- HUS/TTP (Hemolytic uremic syndrome and thrombotic thrombocytopenic purpura)
- Myeloma
- Amyloidosis
- Drugs
Name 4 CVS diseases which affect the kidney
Cardiac failure
Atheroembolism
Hypertension
Atherosclerosis
Name 3 systemic disease infections which affect the kidney
Sepsis
Post-infectious GN
Infective endocarditis
Name 3 systemic diseases which inflame the blood vessels and affect the kidney
SLE
Vasculitis
Scleroderma and other connective tissue diseases
Cryoglobulinaemia
Single causes of ESRF
Inc diabetes, GN, renal vascular disease, hypertension
Name 5 types of drugs which affect the kidney
Aminoglycosides
ACEI
Penicillamine, gold
NSAIs
Radiocontrast
Describe the 4 stages of the natural history of diabetic nephropathy (development of proteinuria and decline in GFR)
- Silent sub-clinical phase; hyperfiltration; increased GFR
- Microalbuminaemia (20-200ug/d)
- Clinical nephropathy (proteinuria > 0.5g/d)
- Established renal failure
What is the commonest single cause of ESRF (leading to the need for dialysis or transplantation)?
Diabetes
Does diabetic nephropathy depend on the type of diabetes you have?
No, it depends on glycaemic control
Type 1 and type 2 are equally at risk
What is increasing proteinuria usually associated with?
Declining GFR
What is chronic kidney disease classification based on?
Kidney function/GFR:
Show the relationship with stages of CKD and CVS disease complications
Give 2 common causes of renal failure in older patients (vascular)
Reno-vascular disease
Atheroembolic disease (eosinophilia, peripheral skin lesions, warfarin therapy, vascular procedures)
What is vasculitis?
Inflammatory reaction in the wall of any blood vessel
Defined by size of vessel involved
Can affect single or multiple organs
Wide spectrum of clinical presentations
3 broad nomenclatures for vasculitis
- Aorta/large artery
- Medium artery
- Small vessel
What are the 2 aorta/large vessel vasculitis?
Takayasu arteritis
Giant cell arteritis
What are the 2 medium artery vasculitis?
Polyarteritis nodosa
Kawasaki disease
What are the 3 small vessel vasculitis?
Wegener’s granulomatosis
Microscopic polyarteritis
Churg-Strauss syndrome
What is Wegener’s granulomatosis?
Granulomatous inflammation in resp tract
What type of GN does Wegener’s cause?
Focal necrotising GN with crescents
What demographic is more likely to be affected by Wegener’s?
Males slightly more common
Affects all ages, most common 40-60y
How does Wegener’s present in the upper vs lower resp tract?
Upper = epistaxis, nasal deformity, sinusitis, deafness
Lower = cough, dyspnoea, haemoptysis, pulmonary haemhorrage
What else does Wegener’s present with (inc kidney)?
Kidney = glomerulonephritis
Joints = arthralgia, myalgia
Eyes = scleritis
Heart = pericarditis
Systemic = fever, weight loss, vasculitic skin rash
What does microscopic polyarteritis have a similar clinical spectrum to?
Wegner’s granulomatosis
What can microscopic polyarteritis present with?
Systemic disease, renal and pulmonary involvement
(more commonly renal limited disease)
What are methods of diagnosis in vasculitis? (6)
- Urine = blood/protein
- Renal function = raised urea/creatinine
- Biochemistry = raised alk phosp, CRP, low albumin
- Haematology = anaemia, thrombocytosis, leukocytosis
- Immunology = hyperglobulinaemia, positive ANCA
- Renal biopsy
ANCA in vasculitis
What type of ANCA is found in Wegener’s v in Microscopic polyarteritis?
Wegeners = >90% C-ANCA
MP = usually P-ANCA
(ANCA can be false positive e.g. inflammatory bowel disease - importance of renal biopsy)
What is endocarditis?
A result of bacterial (or fungal) infection on cardiac valves
What are the 3 typical bacteria in endocarditis?
Staph aureus
Viridans strep
Enterococci
What does infective endocarditis lead to in the kidney?
Glomerulonephritis (GN) +/- small vessel vasculitis due to immune complex formation
What 3 test results point towards GN (renal involvement) in infective endocarditis?
- Abnormal urea/creatinine
- Haematuria - red cell casts
- Reduced complement levels
How does renal disease recover in infective endocarditis?
When underlying infection is treated
What is multiple myeloma?
A monoclonal proliferation of plasma cells producing an excess of immunoglobulins and light chains
(common in elderly)
What are the clinical features of multiple myeloma?
- Markedly elevated ESR
- Anaemia
- Weight loss
- Fractures
- Infections
- Back pain/cord compression
What 4 investigations are diagnostic for multiple myeloma?
- Bone marrow aspirate >10% clonal plasma cells*
- Serum paraprotein +/- immunoparesis*
- Urinary Bence-Jones protein (BJP) (light chains)*
- Skeletal survey - lytic lesions*
Lytic lesions
How does renal failure manifest in myeloma?
Cast nephropathy (‘myeloma kidney’)
Light chain nephropathy
Amyloidosis
Hypercalcaemia
Hyperuricaemia
Cast nephropathy
Light chain disease: TBM Ig Deposition
Amyloid
Deposition of abnormal fibrillary proteins that persist
Primary/secondary
What history features would make you suspect systemic disease with renal involvement?
Fever, malaiase, weight loss, arthralgia, myalgia, skin rash (vasculitic), gritty eyes, breathlessness, haemoptysis, epistaxis, haematuria, oedema
Give signs for each: hands, face, skin, CVS, chest, locomotor, CNS, which suggest systemic disease with renal involvement
Hands = splinter haemhorrage, purpura, Raynaud’s
Face = scleritis, uveitis, nasal deformity, retinal vasculitis, hypertensive retinopathy
Skin = vasculitic rash, scleroderma
CVS = hypertension, murmur
Chest = crepitations, haemoptysis
Locomotor = joint swelling, tenderness
CNS = stroke, encephalopathy
Give the components of initial investigations into urine and blood
Urine:
- blood/protein on urinalysis
- microscopy - red cell casts
Blood:
- elevated urea/creatinine
- raised CRP
- thrombocytosis, anaemia
- raised alkaline phosphatase
Further blood investigations for systemic disease?
ANCA (anti-MPO/anti-PR3 antibodies)
ANA, dsDNA antibodies
Complement levels C3, C4
Blood cultures
What further investigations for systemic disease can be done?
- Radiology = CXR, USS abdo (renal size), CT thorax (pulm granulomas, interstitial disease), echo
- Biopsy - kidney, nasal mucosa, lung, skin
