The kidneys in systemic disease Flashcards
name some systemic diseases that can affect the kidneys
- diabetes mellitus
- cardiovascular disease
- infection
- inflammation of the blood vessels
- Haemolytic Uraemic Syndrome(HUS)/Thrombotic Thrombocytopenic Purpura (TTP)
- myeloma
- amyloidosis
drugs
give examples of CVS disease that can affect the kidneys
Cardiac failure
Atheroembolism
Hypertension
Atherosclerosis
give examples of infection that can affect the kidneys
Sepsis
Post-infectious GN
Infective endocarditis
give examples if inflammation in the blood vessels that can affect the kidneys
SLE
Vasculitis
Scleroderma and other connective tissue diseases
Cryoglobulinaemia
give examples of drugs that can affect the kidneys
Aminoglycosides NSAIDs
ACE inhibitors Radiocontrast
Penicillamine, gold
in the natural history of diabetic nephropathy describe the four stages of the development of proteinuria and decline in GFR
- silent sub clinical phase
- hyperfiltration
- increased GFR - microalbuminuria
- 20-200 micrograms/day - clinical nephropathy
- proteinuria >0.5g/day - established renal failure
over this time there is a slight rise in GFR at the beginning then constant decline
urinary albumin starts to rise very slowly until GFR >1/2 normal value - sudden rise in urianry albumin until GFR nearly 0 then sudden fall in urianry albumin as kidneys fail
what % of patients with diabetic nephropathy will progress to ESRF
30%
who is more at risk of diabetic nephropathy - Type I or Type II
both are equally at risk
what is the relationship between proteinuria and GFR
as proteinuria increases GFR decreases
what is the single commonest cause of ESRF leading to the need for dialysis or transplantation
diabetic nephropathy
what are the different stages for classifying chronic kidney disease
stage 1
- kidney damage/normal or high GFR
- GFR >90
stage 2
- kidney damage/mild reduction in GFR
- GFR - 60-89
stage 3
- moderately impaired
- GFR - 30-59
stage 4
- severely impaired
- GFR - 15-29
stage 5
- advanced or on dialysis
- GFR <15
what is reno-vascular disease
atherosclerosis affecting the renal artery
- usually unilateral stenosis
- common cause of renal failure in older patients
what are some common causes of atheroembolic disease in renal patients
eosinophilia
peripheral skin lesions
warfarin therapy
vascular procedures
*cholesterol clefts - after intervention, embellished cholesterol moved from plaque, sticks further down in artery - causes blockage
what is vasculitis
inflammatory reaction on the wall of any blood vessel - defined by the size of the vessel involved
can affect single or multiple organs
has a wide spectrum of clinical presentations
what type of vasculitis is present in the aorta/large arteries
takayasu arteritis
giant cell arteritis
what type of vasculitis is present in medium arteries
polyarteritis nodosa
kawasaki disease
what type of vasculitis is present in small vessels
wegeners granulomatosis (granulomatosis polyarteritis)
microscopic polyarteritis
Churg-strauss syndrome
(eosinophilic polyarteritis)
what is wegeners granulomatosis
granulomatous inflammation in the respiratory tract
characteristic focal necrotising glomerulonephritis with crescents
what are upper respiratory tract symptoms of wegeners
Epistaxis (nose bleed), nasal deformity, sinusitis, deafness
what are lower respiratory tract symptoms of wegeners
Cough, dyspnoea, haemoptysis
Pulmonary haemorrhage
what are systemic symptoms of wegeners
fever, weight loss, vasculitic skin rash
name some other areas affected by wegeners and how they present
Kidney
- glomerulonephritis
Joints
- arthralgia, myalgia
Eyes
- scleritis
Heart
- pericarditis
how does microscopic polyarteritis present
similar clinical spectrum to wegeners
can present with systemic disease, renal and pulmonary involvement
Diagnosing vasculitis - what would you look for in the urine
blood
protein
Diagnosing vasculitis - what would you look for in the renal function tests
raised urea
raised creatinine
Diagnosing vasculitis - what would you look for in the biochemistry
raised alk phos
CRP
low albumin
Diagnosing vasculitis - what would you look for in the haematology
anaemia
thrombocytosis
leukocytosis
Diagnosing vasculitis - what would you look for in the immunology
hyperglobulinaemia positive ANCA (antineutrophil cytoplasmic antibodies)
what other diagnostic procedure would help diagnose vasculitis
renal biopsy
check clotting first
What is ANCA
antineutrophil cytoplasmic antibodies
what is the importance of ANCA in diagnosis
2 types can show up on immunostaining
- C-ANCA (cytoplasmic)
- P-ANCA (perinuclear)
can help determine type of disease:
Wegeners = >90% C-ANCA
Microscopic polyarteritis = usually P-ANCA
after immunostaining for ANCA why are renal biopsies still important
ANCA can be a false positive e.g. inflammatory bowel disease so need a renal biopsy to determine if renal involvement
what causes infective endocarditis
bacterial (or fungal) infection on cardiac valves
typically caused by
- staphylococcus aureus
- viridans streptococci
- enterococci
how does infective endocarditis lead to glomerulonephritis +/- small vessel vasculitis
due to immune complex formation
what suggests renal involvement n infective endocarditis
Abnormal urea/creatinine
Haematuria, red cell casts
Reduced complement levels
what is multiple myeloma
a monoclonal proliferation of plasma calls producing an excess of immunoglobulins and light chains
what are clinical features of myeloma
Markedly elevated ESR Anaemia Weight loss Fractures Infections Back Pain /Cord compression
how can multiple myeloma be diagnosed
bone marrow aspire >10% clonal plasma cells
serum paraprotein +/-immunoparesis
urinary bence-jones protein
skeletal survey - lytic lesions
serum free light chains
what would a head x-ray classically show with multiple myeloma
“pepper pot skull” - lots of tiny black lesions
what may cause renal failure in myeloma
1/3rd patients present with kidney disease
cast nephropathy -“myeloma kidney”
light chain nephropathy
amyloidosis
hypercalcaemia - promotes dehydration - can lead to acute kidney injury
hyperuricaemia
what is amyloidosis
depostition of abnormal fibrillary proteins that persist
can be primary/secondary
when should you suspect a systemic disease has renal involvement
when history includes any of:
Fever, malaise, weight loss, arthralgia, myalgia, skin rash (vasculitic), gritty eyes, breathlessness, haemoptysis, epistaxis, haematuria, oedema
what signs of renal involvement may be seen on the hands
Splinter haemorrhages, purpura, Raynaud’s
what signs of renal involvement may be seen on the face
Scleritis, uveitis, nasal cartilage deformity, retinal vasculitis, hypertensive retinopathy
what signs of renal involvement may be seen on the skin
sculitic rash, scleroderma
what signs of renal involvement may be associated with the CVS
hypertension, murmur
what signs of renal involvement may be associated with the chest
crepitations, haemoptysis
what signs of renal involvement may be associated with the locomotor system
joint swelling, tenderness
what signs of renal involvement may be associated with the CNS
stroke encephalopathy
what initial investigations should be done if renal involvement suspected
urine
- bloos/protein urinalysis
- microscopy - red cell casts
blood
- Elevated urea/creatinine
- Raised CRP
- Thrombocytosis, anaemia
- Raised alkaline phosphatase
what further investigations should be done to confirm renal involvement
blood
radiology
biopsy
what further blood investigations should be done
- ANCA (anti-MPO/anti-PR3 antibodies)
- ANA, dsDNA antibodies
- Complement levels C3, C4
- Blood cultures
- Immunoglobulins and electrophoresis
what radiology investigations should be done
CXR
USS abdomen - Renal size
CT thorax - Pulmonary granulomas, interstitital
disease
Echocardiography
what biopsies should be done
kidney, nasal mucosa, lung, skin
