The Kidneys in Systemic Disease Flashcards
What organ receives more blood flow per unit volume than any other organ in the body?
The kidney
What may the glomeruli trap?
Proteins
Immune complexes
What systemic diseases affect the kidneys?
DM Cardiac failure Atheroembolisms HTN Atherosclerosis Sepsis Post infectious glomerulonephritis Infective endocarditis SLE Vasculitis Scleroderma / other connective tissue diseases Cryoglobulinaemia HUS/TTP Myeloma Amyloidosis Drugs
What drugs affect the kidneys?
Aminoglycosides NSAIDs ACE inihibtors Penicillamine Gold Radiocontrast
Stages of diabetic nephropathy
- Silent subclinical phase
- hyperfiltration
- increased GFR - Microalbuminamia (20-200ug/d)
- Clinical nephropathy (proteinuria >0.5g/d)
- Established renal failure
What is the triad of nephropathy?
Proteinuria
Hypoalbuminaemia
Oedema
What are the risks of a T1DM patient developing nephropathy at 10 and 25 years?
10 - 4%
25 - 25%
What are the risks of a patient with T2DM developing nephropathy within 5 and 20 years?
5 - 10%
20 - 30%
What % of those with diabetic nephropathy will progress to ESRF?
30%
What does ESRF stand for?
End stage renal failure
What is the commonest cause of ESRF?
Diabetic nephropathy
What is increasing proteinuria usually assosiated with?
Declining GFR
What is the classification of CKD based on?
Kidney function
What does CKD stand for?
Chronic kidney disease
What does GFR stand for?
Glomerular filtration rate
How many stages does CKD have?
5
What are the 5 stages of CKD?
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 classification system relates CKD to CVS disease?
NKF K/DOQI classification system
What is the commonest cause of renal fialure in older patients?
Reno-vascular disease / atheroembolic disease
Features of atheroembolic disease affecting the kidneys
Eosinophilia
Peripheral skin lesion
Treatment of atheroembolic disease affecting the kidneys
Warfarin
Vascular procedures
Definition of vasculitis
Inflammatory reaction in the wall of any blood vessel
What is vasculitis defined by?
The size of the vessel involved
What vasculitis conditions affect aorta / large arteries?
Takayasu arteritis
Giant cell arteritis
What vasculitis conditions affect the medium sized arteries?
Polyarteritis nodosa
Kawasaki disease
What vasculitis conditions affect the small vessel arteries?
Wegeners granulomatosis
Microscopic polyarteritis
Churg-strauss syndrome
What is wegeners granulomatosis?
Granulomatous inflammation in the respiratory tract
How does wegeners granulomatosis affect the kidneys?
Focal necrotising GN with crescents
Who does wegners more commonly affect?
Males
40-60 y/o
Presentation of wegeners
Epistaxis Nasal deformity Sinusitis Deafness Cough Dyspnoea Haemopytsis Pulmonary haemorrhage GN Arthralgia Myalgia Scleritis Pericarditis Fever Weight loss Vasculitic skin rash
What can microscopic polyarteritis present with?
Systemic disease
Renal involvement
Pulmonary involvement
Investigations for vasculitis
Urine - blood/protein Renal function - raised creatinine/urea Biochemistry - raised ALP, CRP, low albumin Anaemia Thrombocytosis Leucocytosis Hyperglobulinaemia Positive ANCA Renal biopsy
What immunological molecule is seen in wegeners?
> 90% C-ANCA
What immunological molecule is usually seen in microscopic polyarteritis?
P-ANCA
Can ANCA be a false positive? Give an example
Yes
IBD
What is infective endocarditis?
Endocarditis as a result of bacterial or fungal infection on the cardiac valves
Causative organisms of infective endocarditis
Staph aureus
Viridans streptococci
Enterococci
What can infective endocarditis lead to in the kidneys?
GN +/- small vessel vasculitis due to immune complex formation
What does GN stand for?
Glomerulonephritis
What is myeloma?
A monoclonal proliferation of plasma cells producing an excess of immunoglobulins and light chains
Who is myeloma common in?
Elderly
Presentation of myeloma
Marked elevation of ESR Anaemia Weight loss Fractures Infections Back pain / cord compression
Diagnosis of myeloma
Bone marrow aspirate >10% clonal plasma cells
Serum paraprotein +/- immunoparesis
Urinary Bence-Jones protein
Skeletal survery for lytic lesions
What does myeloma cause in the kidneys?
Cast nephropathy - 'myeloma kidney' Light chain nephropathy Amyloidosis Hypercalcaemia Hyperuricaemia
What does light chain disease lead to in the kidneys?
TBM IgM deposition
What is amyloidosis?
Deposition of abnormal fibrillary proteins that persist
What presentation would indicate there is renal involvement in the systemic disease?
Fever Malaise Weight loss Arthralgia Myalgia Vasculitic skin rash Gritty eyes Breathlessness Haemoptysis Epistaxis Haematuria Oedema Hands - splinter haemorrhages - purpura - raynauds Face - scleritis - uveitis - nasal cartilage deformity - retinal vasculitis - HTN retinopathy - scleroderma - HTN - murmur Haemoptysis Crepitations Joint Swelling / tenderness Stroke Encephalopathy
Investigations if suspect renal involvement in systemic disease
Urine dipstick Bloods - urea creatinine - CRP - anaemia - thrombocytosis - raised ALP - ANCA - Complement levels - blood cultures - CXR - USS abdo - CT thorax - ECHO Biopsy of - kidney - nasal mucosa - lung - skin
Who is HUS usually seen in?
Children
Triad of HUS
AKI
Microangiopathic haemolytic anaemia
Thrombocytopenia
Causes of HUS (secondary)
E coli 0157
Pneumococcal infection
HIV
Rare; SLE, cancer, drugs
Who is Ecoli the most common cause of HUS in?
Children
What is primary HUS due to?
Complement dysregulation
Investigations of HUS
FBC - anaemia - thrombocytopenia - fragmented blood film U + Es - AKI Stool culture
Management of HUS
Supportive
What does ADPKD stand for?
Autosomal dominant polycystic kidney disease
Presentation of ADPKD
HTN Recurrent UTIs Abdo pain Renal stones Haematuria CKD Extra renal manifestations
What are the extra renal manifestations of ADPKD
Liver cysts (70%) which manifests as hepatomegaly
Berry aneurysms (8%)
MVP, Aortic root dilatation, aortic dissection, mitral/tricuspid incompetence
Diverticulosis
Ovarian cysts
If a berry aneurysm ruptures, what may this cause?
SAH
What is the screening test for adult polycystic kidney disease?
USS
Osmolalities in Diabetes insipidus
High plasma osmolality
Low urine osmolality
Treatment of ascites
Spironolactone
What can the accumulation of amyloid fibrils lead to?
Tissue/organ dysfunction
Diagnosis of amyloidosis
Congo red staining; apple-green birefringence
Serum amyloid precursor (SAP) scan
Biopsy of rectal tissue
Presentation of amyloidosis
SOB Weakness Hepatomegaly Proteinuria Worsening renal function
What age does amyloidosis typically present in?
50 - 65 y/o
What does HSP stand for?
Henoch-Schonlein Purpura
What is HSP?
IgA mediated small vessel vasculitis
Who is HSP usually seen in?
Children following an infection
What does HSP have a degree of overlap with?
IgA nephropathy (Bergers disease)
Presentation of HSP
Palpable purpuric rash (with localised oedema) over buttocks and extensor surfaces of arms and legs
Abdominal pain
Polyarthritis
Features of IgA nephropathy may occur e.g.
- haematuria
- renal failure
Treatment of HSP
Supportive
Analgesia for arthralgia
Prognosis of HSP
Excellent
Self limiting
Especially in children with no renal involvement
How many patients with HSP have a relapse?
1/3rd
What screening is done for diabetic nephropathy?
Albumin:Creatinine Ratio (ACR) - early morning specimen
What ACR is indicative of microalbuminuria?
> 2.5
Size of diabetic nephropathy kidneys on USS
Large / normal sized
Size of kidneys of most patients with CKD
Small kidneys
What is the earliest clinical detection manifestation of diabetic nephropathy?
Microalbuminuria
