Renal Flashcards
What is nephrotic syndrome characterised by? (hint Protein LEAC)
Heavy proteinuria >3.5 g/d, hypoalbumniaemia, oedema and hyperlipidaemia. Protein Lipids Edema Albumin low Cholesterol up
What dietary modification is of most benefit in nephrotic syndrome?
Low Na diet
IgA nephropathy. Cause? Epid? Clin? RF? Dx? Tx?
IgA nephropathy may primarily involve only one kidney or may be secondarily associated with other conditions such as HIV infection, chronic liver disease, IBD or coeliac disease.
Patho
IgA nephropathy, the most common primary glomerulonephritis, is an immune complex disease in which IgA antigen-antibody complexes are deposited primarily in the mesangium.
IgA nephropathy may primarily involve only the kidney or may be secondarily associated with other conditions such as HIV infection, chronic liver disease, inflammatory bowel disease, or celiac disease. IgA nephropathy is the renal lesion of Henoch-Schönlein purpura, a systemic vasculitis most commonly seen during childhood.
Epid:
Primary IgA nephropathy occurs at any age and has a predilection to develop in men who are white or Asian. Approximately 20% to 30% of patients have progressive disease that can lead to ESKD within 10 to 20 years of onset.
RF:
Risk factors associated with progressive CKD include younger age at onset; hypertension; proteinuria ≥1 g/24 h; elevated serum creatinine levels; low GFR; and secondary glomerulosclerosis, chronic tubulointerstitial changes, and crescents on biopsy. Persistent proteinuria (≥1 g/24 h) and hypertension are two modifiable risk factors that increase the risk of progression to advanced CKD.
Clinical:
Most patients with IgA nephropathy are asymptomatic at presentation, with only microscopic hematuria and proteinuria discovered on evaluation of the urine.
A common presentation of primary IgA nephropathy is recurrent gross hematuria occurring synchronously with an episode of respiratory (“synpharyngitic hematuria”) or gastrointestinal infection.
This may be associated with acute kidney injury precipitated by occlusion of tubular lumina by erythrocytes and erythrocyte casts.
Less frequently, patients may present with the nephrotic syndrome or RPGN.
Dx:
Diagnosis is confirmed by kidney biopsy, which demonstrates mesangioproliferative glomerulonephritis with IgA-dominant mesangial immune deposits on immunofluorescence microscopy.
Mx:
Corticosteroids with immunosuppressive agents and antiplatelet agents may be beneficial in the management of primary MPGN but more than 50% of patients progress to advanced CKD.
Treatment of secondary MPGN I is directed toward the underlying cause.
What is the most common extra-renal manifestation of PCOS?
Hepatic cysts - 94% Mitral valve prolapse 25% Abdominal hernia 10% Intracranial aneurysm 8% Colonic diverticuli
Which drug commonly causes AIN?
Antibiotics (Betalactams - pen, cephal, carbo, fluoroquinolones - cipro, norflox, moxiflox, sulfonamides - trimetho) and PPI e.g. ciproflox)
Patient with LVEF 16% and oliguric renal failure with symptoms. What intervention is appropriate?
Insertion of tenckhoff catheter for peritoneal dialysis, minimise risk of acute ischaemia.
Haemodialysis not suitable due to cardiac failure.
Which organism is most likely in a pt on peritoneal dialysis with abdo infection?
S. epidermis 50%
Culture negative infections 20%
Gram -ve 15%
T/F. Proteinuria is the strongest predictor of poor outcome in a patient with chronic kidney disease?
True, increases risk by 4-fold
Which antigen is targeted in Idiopathic membranous nephropathy?
Phospholipase A2 receptor (NEJM)
MOA Sirolimus? Indications?
mTOR inhibitor. Prevents action of B cells and T cells by inhibiting IL-2
Indication: post transplant anti-rejection, Coronary stents
AE: impaired wound healing, myelosuppresion, pneumonitis, infertility
Which circulating factor causes FSGS (Focal segmental glomerulosclerosis)?
suPAR (Nature, 2011)
In post-kindey tranplant, switching to sirolimus will reduce risk of death. T/F
False, meta analysis have shown there is a higher death ate on MTORi
MOA of Tacrolimus? Indications?
inhibits production of IL-2, a molecule that promotes the production of proliferation of T cells
Post allogenic transpant
Eczema a T cell mediated disease
Minimal change disease
What is the mechanism behind a metabolic alkalosis associated with vomiting in a pt with severe HF on a salt restriction and frusemide?
Chloride depletion from vomiting frusemide (NaCl) results in contraction alkalosis due to secondary activation of aldosterone hence Na retention for H/K excretion.
What test can you do to differentiate from primary and central DI?
DDAVP - urine osmo does not change in primary DI.
urine osmo will respond in Central DI.
What are the common characteristics of Liddle’s syndrome?
Hypertension, short and FLK
What are the common characteristics of Gordon’s syndrome?
HT
HyperK
acidosis
Rare
What are the common characteristics of Bartter’s syndrome?
Young
Dry
Like taking lots of Frusemide
What are the common characteristics of Gittleman’s syndrome?
Thiazide effect
Low serum Mg
Low serum K
Alkaloctic pH
Urine K increased
Mycophenalate is safe is pregnancy. T/F
False.
Switch to azathioprine 3 months before conception to reduce the risks of congenital birth defects
Live kidney donation is a better option for most patients with ESKD?
True, survival 1.5-2x better than deceased donor Tx
Post kidney function is 70% of predonation? T/F
True
Pt with renal artery stenosis on ACEI and CCB. BP not controlled. Next step?
Add thiazide
If not controlled on ACEI alone, add long acting CCB, aldosterone antagonist or BB.
In unilateral renal artery stenosis, when is revascularisation (stenting/angioplasty) indicated over medical therapy alone (must meet 1 of 4 criteria)?
Short duration of BP elevation prior to Dx of renovascular disease since this is the strongest clinical predictor of a fall in BP after renal revascularisation
Failure of optimal medical therapy to control BP
Intolerance to optimal medical therapy
Recurrent flash of pul oedema and/or refractory HF
Studies have indicated there was no significant difference in medical therapy vs revascularisation, even in pts with 80% stenosis
Pt pregnant, previous VTE due to Sx. Mx during pregnancy?
Clinical surveillance preferred over thromoprophylaxis unless multiple VTEs have occurred.
Threshold for thromboprophylaxis is lowered in the post part period as there is an increased with of VTE. 2-5 x more common beyond post partum.
Minimal change disease. What? Cause?Clinical? Dx?Tx?
Nephrotic syndrome associated with atopic diseases and lymphomas.
Most common cause of nephrotic syndrome in children. 10-15% adults.
A disorder of lymphocytes which release IgG and cytokines that alter glomerular capillary permselectively.
Cause:
idiopathic
NSAID related
paraneoplastic e.g. HL
Clinical
Significant proteinuria
Dx
•Confirmed with kidney Bx
•Light and Immunofluoresecence microscopy are normal. NO immune complexes.
•Electron microscopy demonstrates characteristic fusion and effacement of podocytes (visceral epithelial cell) foot processes.
Mx
Prednisone
If relapse, consider cyclophosphamide
If relapse or gonadal toxicity with cyclophosphamide consider cyclophosphamide
If fails cyclophosphamide and cyclosporin, consider rituximab
Loop diuretic resistance is due to? Tx?
increased tubular Na reabsorption in nephron segments other than the loop of Henle.
The decreased response to the action of a diuretic that results from increased Na reabsorption on other nephron segment has been called the diuretic braking phenomenon.
Tx:
Increase loop diuretic to BD, TDS dosing if patient has partial but adequate response to dosing
A thiazide diuretic added
T/F. Changes in the charge or size of the selective barrier in the GBM is involved in the pathology of nephrotic syndrome?
True
Nephrotic urine reflects defects in the selectivity glomerular ultrafiltration
In nephrotic syndrome, what is the protein loss due to?
glomerular proteinuria characterised by increased filtration of macromolecules across the glomerular capillary wall
Idiopathic nephrotic syndrome (membranous nephropathy, minimal change diseases, focal segmental glomerulasclerosis). What is the major cause of proteinuria?
Podocyte is the major target of injury - podocyte foot process effacement, slit diaphragm disruption and depletion of podocytes.
What is the pathophy of adult onset idiopathic membranous nephropathy and FSGS?
Pathology?
Cause?
autoabs to podocyte antigens
circulating factors like soluble urokinase-type plasminogen activator receptor that activate podocyte integrins or circulating factors like cytokines or microbial products that may induce podocyte CD80
Pathology:
Focal =
What is erythropoietin produced in response to?
Synthesised in kidneys, in peritubular cells.
Erythropoietin stimulates proliferation and maturation of erythroid cells through ligand binding to the erythropoietin receptor.
Pathogenesis of contrast nephropathy?
Main mechanism of contrast induced nephropathy is intra-renal vasoconstriction.
Medicated by vasoactive mediators such as endothelin and adenosine.
Reduction in renal perfusion is caused by direct effect of contrast media on kidney and toxic effects on the tubular cells are generally accepted as the main factors in pathophys.
What is the most common organism in PD peritonitis?
Co-ag -ve S. aureus is the most common in Australia. (Staph aureus in America)
What is the most likely non-SCC malignancy in renal transplant patients?
Lymphoma
AG, normal range?
7-13 (traditionally 8-16)
Causes of Normal AG Metabolic acidosis?
Diarhhoea
RTA
- If RTA cannot be distinguished from diarrhoea, calculate urine AG
- Urine AG is +ve with NAGMA secondary to RTA
- Urine AG is negative with NAGMA seoncardy to GI losses
CA inhibitors
Hyperalimentation with TPN
Causes of High AG metabolic acidosis?
ketoacidosis
uremia (CRG)
lactic aciodis
toxins
Pt with URTI, haematuria, subnephrotic range proteinuria and mesangial depositis that stain for IgA. Dx?
IgA nephropathy
Pt with hx of recent infection (any infection, but most likely streptococcal 2-3 weeks prior), haematuria, subnephrotic range proteinuria, red cell casts and ASOT normal, glomeruli have large sub epithelial hump like deposits, elevated. Dx?
Post infectious GN
T/F. Changes in the charge or size of the selective barrier in the GBM is involved in the pathology of nephrotic syndrome?
- True
* Nephrotic urine reflects defects in the selectivity of glomerular ultrafiltration
In nephrotic syndrome, what is the protein loss due to?
- glomerular proteinuria characterised by increased filtration of macromolecules across the glomerular capillary wall
- cytokine injury to podocytes and loss of charge on GBM
Idiopathic nephrotic syndrome (membranous nephropathy, minimal change diseases, focal segmental glomerulosclerosis). What is the major cause of proteinuria?
•Podocyte is the major target of injury - podocyte foot process effacement, slit diaphragm disruption and depletion of podocytes.
What is the pathophy of adult onset idiopathic membranous nephropathy and FSGS?
autoabs to podocyte antigens
- circulating factors like soluble urokinase-type plasminogen
- activator receptor that activate podocyte integrins or
- circulating factors like cytokines or microbial products that may induce podocyte CD80.
What is the most common cause of nephrotic syndrome in adults? Causes of primary and secondary? Presentation? Dx? Tx?
Diffuse membranous glomerulopathy
Primary
- in situ immune complex disease in which the Ig of The IgG class react with constitutive or planted antigens in the outer aspect of the GBM
- mainly adults > 50 y
- 2/3 of pts undergo spontaneous complete or partial remission and 1/3 have progressive disease that may result in ESRF within 10 years
Secondary
- SLE
- Infections: Hep B, C, malaria
- malignancies
- NSAIDs
Presentation:
- Nephrotic syndrome - think Protein LEAC
- highest prevalence of renal vein thrombosis compared with other causes of nephrotic syndrome
Dx
- Kidney Bx shows diffuse thickening of the glomerular capillary wall on light microscopy and intra membranous electron dense deposits initially located in the sub epithelial aspect of the glomerular basement membrane on electron microscopy
Mx
- Depends on mild, mod, severe proteinuria
- commence on ACEI
- If proteinuria 4-8 g/d, immunosuppresive therapy with cyclophosphamide/corticosterouds or calcineurin inhibitor
- check cholesterol q1-3 months
- commence anticoagulation of symptoms of renal vein thrombosis.
What dietary modification is of most benefit in nephrotic syndrome?
Low Na diet
IgA nephropathy *GN). Cause? Epid? Clin? RF? Dx? Tx?
IgA nephropathy may primarily involve only one kidney or may be secondarily associated with other conditions such as HIV infection, chronic liver disease, IBD or coeliac disease.
Patho
•IgA nephropathy, the most common primary glomerulonephritis, is an immune complex disease in which IgA antigen-antibody complexes are deposited primarily in the mesangium.
•IgA nephropathy may primarily involve only the kidney or may be secondarily associated with other conditions such as HIV infection, chronic liver disease, inflammatory bowel disease, or celiac disease. IgA nephropathy is the renal lesion of Henoch-Schönlein purpura, a systemic vasculitis most commonly seen during childhood.
Epid
•Primary IgA nephropathy occurs at any age and has a predilection to develop in men who are white or Asian. Approximately 20% to 30% of patients have progressive disease that can lead to ESKD within 10 to 20 years of onset.
RF
•Risk factors associated with progressive CKD include younger age at onset; hypertension; proteinuria ≥1 g/24 h; elevated serum creatinine levels; low GFR; and secondary glomerulosclerosis, chronic tubulointerstitial changes, and crescents on biopsy. Persistent proteinuria (≥1 g/24 h) and hypertension are two modifiable risk factors that increase the risk of progression to advanced CKD.
Clinical
•Most patients with IgA nephropathy are asymptomatic at presentation, with only microscopic hematuria and proteinuria discovered on evaluation of the urine.
•A common presentation of primary IgA nephropathy is recurrent gross hematuria occurring synchronously with an episode of respiratory (“synpharyngitic hematuria”) or gastrointestinal infection.
•This may be associated with acute kidney injury precipitated by occlusion of tubular lumina by erythrocytes and erythrocyte casts.
•Less frequently, patients may present with the nephrotic syndrome or RPGN.
Dx
•Diagnosis is confirmed by kidney biopsy, which demonstrates mesangioproliferative glomerulonephritis with IgA-dominant mesangial immune deposits on immunofluorescence microscopy.
Mx
•Corticosteroids with immunosuppressive agents and antiplatelet agents may be beneficial in the management of primary MPGN but more than 50% of patients progress to advanced CKD.
•Treatment of secondary MPGN I is directed toward the underlying cause.
What is the most common extra-renal manifestation of PCOS?
Hepatic cysts - 94%
Mitral valve prolapse 25%
Abdominal hernia 10%
Intracranial aneurysm 8%
Colonic diverticuli
Renal transplant: What feature of acute rejection has the worst prognostic implication?
Vascular injury .
Long term survival is base don initial response to therapy.
What are the recommendations for metformin dosing based on eGFR?
eGFR =45:
- continue use
Monitor RF q 3-6 months
eGFR = 30:
- presecribe metformin with caution
- use lower dose e.g. 50% or half maximal dose
- Monitor RF q3months
- do not start new patients on Metformin
eGFR
What is the most common infection post renal transplant?
E. coli
What is calciphylaxis? Tx?
Condition characterized by calcification of arterioles resulting in ischaemia and necrosis.
Presentation:
Excruciating pain
Violaceous painful, plaque like SC nodules that progress to ischaemic/necrotic ulcers.
Tx:
Multifactorial approach. Optimal therapy unknown.
Wound care, analgesia, avoidance of trauma.
O2 therapy 2-3hrs/d or hyperbaric O2 therapy.
Correct hypercalcaemia and phosphate
- phosphate binders sevelamer (non Ca containing)
If PTH high, cinacalcet
Parathyroidectomy if uncontrolled Ca and PO4.
Increased haemodialysis.
Post infectious GN characterised by?
Nephritis: proteinuria, haematuira, oedema, HTN and AKI.
Strep pharyngitis or cellulitis 2-3 weeks prior
Ix:
MICROSCOPIC HAEMATURIA with leucs and 24 hr urinary albumin of 227 mg.
(IgA nephropathy and Sickle cell disease present with gross hematuria)
Low C3 Normal or low C4 Elevated anti-streptolysin O and anti-deoxyribonuclease B Positive streptozyme test - most useful test as measures the 5 antibodies that may be elevated with a recent strep infection: anti-streptolysin O anti-deoxyribonuclease B Anti-hyalaruronidase Antistreptokinase Antinicotinamide
Tx:
Supportive
Tx underlying infections
No evidence for steroids
What is ANCA (pauci-immune) vasculitis charcterised by?
ANCA +ve
Normal complement levels
Abscence of Ig on immunoflourescent staining of kidney biopsy
Antiglomerular basement membrane disease is characterised by normal complements. T/F
True
What is analgesic nephropathy characterized by on CT?
Papillary necrosis and calcifications in the renal papilla with irregular kidney contours and reduced size.
Due to long term use of NSAIDs, aspirin, codeine, acetominophen.
May present with flank pain, haematuria obstruction from papillary necrosis.
When is sevelamer indicated?
To reduce serum Ph in ESRF
What is Teriparatide?
Synthetic form of PTH used to treat severe OP.
CI in pts with hypercalcaemia.
Which nephrotic syndrome is most commonly associated with renal vein thrombosis?
Membranous nephropathy (disease of old) Presents with haematuria and flank pain
Image with CT, MRI, duplex US
Commence on anticoagulation to salvage renal function
Muddy brown urine suggestive of?
ATN and related to the presence of granular casts in the urine
Red urine without haematuria suggestive of?
Medications or ingestion of beets
Haematuria due to structural lesion in kidnyy or urinary tract or from abnormalities of the BM.
Grains in urine suggestive of?
Urolithiasis
What is the most likely cause of a pt with fever, rash and acute injury after starting a new medication?
Acute interstitial nephritis.
Medications account for 75% of cases - Abx, NSAIDs, PPIs
