Nephrology Flashcards
what kind of anaemia do you usually get in CKD
normocytic anaemia
what does anaemia in CKD lead to?
left ventricular hypertrophy
what are the causes of anaemia in CKD?
reduced EPO levels which leads to diminished red blood cell production
reduced absorption of iron
reduced erythropoesis due to toxic effects of uraemia on bone marrow
reduced red cell survival especially in haemodyalysis
blood loss due to capillary fragility and poor lately function
stress ulceration leading to chronic blood loss
how does CKD cause reduced absorption of iron?
epcidin is an acute-phase reactant
in CKD, hepcidin levels are often increased due to inflammation and reduced renal clearance
elevated hepcidin levels lead to decreased iron absorption from the gut and impaired release of stored iron from macrophages and hepatocytes, reducing the iron available for erythropoiesis
additionally, metabolic acidosis, a common condition in CKD, can inhibit the conversion of ferric iron (Fe³º) to its absorbable form, ferrous iron (Fe²º), in the duodenum → reduced iron absorption.
how is anaemia in CKD managed?
aim for Hb 100 - 120
oral iron should be offered for patients not erythropoiesis agents
if target Hb levels not reached in 3 months patients should be on IV iron
ESAs such as EPO or darbepoetin should be used in those who are likely to benefit in terms of quality of life and physical function
those on ESAs generally require IV iron
what are the complications of nephrotic syndrome?
Increased risk of VTE related to loss of antithrombin III and plasminogen in the urine
DVT, PE , renal vein thrombosis, resulting in a sudden deterioration in renal function
hyperlipidaemia- increasing risk of acute coronary syndrome, stroke etc
chronic kidney disease
increased risk of infection due to urinary immunoglobulin loss
hypocalcaemia (vitamin D and binding protein lost in urine)
what is minimal change disease?
a form of nephrotic syndrome
accounts of 75% of cases in children and 25% of cases in adults
what is the pathophysiology of minimal change disease?
T-cell and cytokine mediated damage to the glomerular basement membrane –> polyanion loss
the resultant reduction of the electrostatic charge - increase glomerular permeability to serum albumin
what are the features of minimal change disease and what is seen on renal biopsy?
nephrotic syndrome
Normotension, hypertension is rare
highly selective proteinuria - only intermediate sized proteins such as albumin and transferrin leak through the glomerulus
renal biopsy - normal glomeruli on light microscopy
electron microsocopy shows fusion of podocytes and effacement of foot processes
how is minimal change disease managed?
oral corticosteroids - majority of cases are steroid responsive - 1mg/kg daily
cyclophosphamide is the next step
what is the prognosis in minimal change disease ?
1/3 have just one episode
1/3 have infrequent relapses
1/3 have frequent relapses which stop before adulthood
what is nephrotic syndrome characterised by?
- Proteinuria (> 3g/24hr) causing
- Hypoalbuminaemia (< 30g/L) and
- Oedema
what are the causes of nephrotic syndrome?
Primary causes: Minimal change disease, focal segmental glomerulosclerosis (FSGS), membranous nephropathy.
Secondary causes: Diabetes mellitus, systemic lupus erythematosus (SLE), amyloidosis, infections (HIV, hepatitis B and C), drugs (NSAIDs, gold therapy).
why is there an increased risk of thrombosis in nephrotic syndrome>
Loss of antithrombin-III, proteins C and S and an associated rise in fibrinogen levels predispose to thrombosis
what are the characteristics and symptoms of nephritic syndromes?
haematuria
hypertension
mild proteinuria <3.5g/day
mild oedema
oliguria and uraemia
what are types of nephritic syndromes?
IgA nephropathy
post strep glomerular nephritis
rapid progressive glomerular nephritis -
anti GBM glomerularnephritis
ANCA vasculitis
what are the types of autosomal dominant polycystic kidney disease?
Type 1 - 85% of cases, chromosome 16, presents with renal failure earlier
Types 2 - 15% of cases - chromosome 4
what is the USS diagnostic criteria for patient with a positive family history?
two cysts, unilateral or bilateral, if aged < 30 years
two cysts in both kidneys if aged 30-59 years
four cysts in both kidneys if aged > 60 years
how is PKD managed?
tolvaptan (vasopressin receptor 2 antagnost
Nice recommends the use of it if:
they have chronic kidney disease stage 2 or 3 at the start of treatment
there is evidence of rapidly progressing disease and
the company provides it with the discount agreed in the patient access scheme.
what is the classification of CKD?
1 Greater than 90 ml/min, with some sign of kidney damage on other tests (if all the kidney tests* are normal, there is no CKD)
2 60-90 ml/min with some sign of kidney damage (if kidney tests* are normal, there is no CKD)
3a 45-59 ml/min, a moderate reduction in kidney function
3b 30-44 ml/min, a moderate reduction in kidney function
4 15-29 ml/min, a severe reduction in kidney function
5 Less than 15 ml/min, established kidney failure - dialysis or a kidney transplant may be needed
When does post step glomerulonephritis develop compared to IgA nephropathy?
PSGN - develops 1-2 weeks after URTI
IgA nephropathy develops 1-2 days after URTI
what is post-streptococcal glomerulonephritis?
Post-streptococcal glomerulonephritis typically occurs 7-14 days following a group A beta-haemolytic Streptococcus infection (usually Streptococcus pyogenes). It is caused by immune complex (IgG, IgM and C3) deposition in the glomeruli. Young children are most commonly affected.
what are the features of post streptococcal glomerulonephritis?
general - headache, malaise
visible haematuria
proteinuria - this may result in oedema
hypertension
oliguria
what would bloods show in post-steptococcal glomerulopnephririts ?
raised anti-streptolysin O titre are used to confirm the diagnosis of a recent streptococcal infection
low C3
what would renal biopsy show in post streptococcal glomerulonephritis?
post-streptococcal glomerulonephritis causes acute, diffuse proliferative glomerulonephritis
endothelial proliferation with neutrophils
electron microscopy: subepithelial ‘humps’ caused by lumpy immune complex deposits
immunofluorescence: granular or ‘starry sky’ appearance
what is Fanconi syndrome?
Fanconi syndrome - describes a generalised reabsorptive disorder of renal tubular transport in the proximal convoluted tubule
resulting in the excretion of most amino acids, glucose, and phosphate
what does fanconi syndrome result in?
type 2 (proximal) renal tubular acidosis
polyuria
aminoaciduria
glycosuria
phosphaturia
osteomalacia
what are the causes of Fanconi syndrome?
cystinosis (most common cause in children)
Sjogren’s syndrome
multiple myeloma
nephrotic syndrome
Wilson’s disease
what are the features of autosomal dominant polycystic kidney disease?
hypertension
recurrent UTIs
flank pain
haematuria
palpable kidneys
renal impairment
renal stones
what are the extra renal manifestations of autosomal dominant polycystic kidney disease?
liver cysts (70% - the commonest extra-renal manifestation): may cause hepatomegaly
berry aneurysms (8%): rupture can cause subarachnoid haemorrhage
cardiovascular system: mitral valve prolapse, mitral/tricuspid incompetence, aortic root dilation, aortic dissection
cysts in other organs: pancreas, spleen; very rarely: thyroid, oesophagus, ovary
diverticulosis
when is plasma exchange indicated?
aka plasmapheresis
Guillain-Barre syndrome
myasthenia gravis
Goodpasture’s syndrome
ANCA positive vasculitis if rapidly progressive renal failure or pulmonary haemorrhage
TTP/HUS
cryoglobulinaemia
hyperviscosity syndrome e.g. secondary to myeloma
what are the complications of plasma exchange?
hypocalcaemia: due to the presence of citrate used as an anticoagulant for the extracorporeal system
metabolic alkalosis
removal of systemic medications
coagulation factor depletion
immunoglobulin depletion
what kind of murmur is heard in mitral valve prolapse?
late systolic murmur accompanied by a mid-systolic click, best auscultated at the cardiac apex. The mid-systolic click is attributable to the abrupt tensioning of the mitral valve leaflets as they prolapse into the atrium during systole.
what are the different types of testicular cancer?
germ cell tumours account for 95% of tumours - can be divided into seminomas and non seminomas (including embryonal, yolk sac, teratoma, and choriocarcinoma)
Non germ cell tumour include leading cell tumours and sarcomas.
what are the risk factors for testicular cancer?
infertility (increases risk by a factor of 3)
cryptorchidism
family history
Klinefelter’s syndrome
mumps orchitis
what are the features of testicular cancer?
a painless lump is the most common presenting symptom
pain may also be present in a minority of men
hydrocele
gynaecomastia
why does gynaecomastia occur in testicular cancer?
this occurs due to an increased oestrogen:androgen ratio
germ-cell tumours → hCG → Leydig cell dysfunction → increases in both oestradiol and testosterone production, but rise in oestradiol is relatively greater than testosterone
leydig cell tumours → directly secrete more oestradiol and convert additional androgen precursors to oestrogens
what ate the tumour markers in testical cancer?
seminomas: seminomas: hCG may be elevated in around 20%
non-seminomas: AFP and/or beta-hCG are elevated in 80-85%
LDH is elevated in around 40% of germ cell tumours
how is prostate cancer managed?
localised T1/T2 - conservative - active monitoring and watchful waiting, radical prostatectomy, radiotherapy - external beam and brachytherapy
Localised advanced T3/T4 - hormonal therapy, radical prostatectomy, radiotherapy - external beam brachytherapy
metastatic prostate cancer - one of the key aims of treating advanced prostate cancer is reducing the androgen levels with hormone treatment
what is a complication of radiotherapy in prostate cancer?
patients may develop proctitis and are also at increased risk of bladder, colon, and rectal cancer following radiotherapy for prostate cancer
what hormone treatment is used in prostate cancer?
anti- androgen therapy
GnRH agonists (Goserelin - Zoladex) or antagonist (degaarelix)
Bicalutamide - non-steroidal anti-androgen, blocks the androgen receptor
Cyproterone acetate - steroidal anti-androgen - prevents DHT binding from intracytoplasmic protein complexes
Abiraterone - androgen synthesis inhibitor - used in hormone relapsed metastatic prostate cancer in patients who have no or mild symptoms after androgen deprivation therapy has failed
how do GnRH agonists work ?
paradoxically result in lower LH levels longer term by causing overstimulation, resulting in disruption of endogenous hormonal feedback systems. The testosterone level will therefore rise initially for around 2-3 weeks before falling to castration leves
initially therapy is often covered with an anti-androgen to prevent a rise in testosterone - ‘tumour flare’. The resultant stimulation of prostate cancer growth may result in bone pain, bladder obstruction and other symptoms
what chemotherapy is used in prostate cancer?
docetaxel
how do you calculate anion gap?
(sodium + potassium) - (bicarbonate + chloride)
what is a normal anion gap?
8-14 mmol/L
what can cause a normal anion gap metabolic acidosis?
Causes of a normal anion gap or hyperchloraemic metabolic acidosis
gastrointestinal bicarbonate loss: diarrhoea, ureterosigmoidostomy, fistula
renal tubular acidosis
drugs: e.g. acetazolamide
ammonium chloride injection
Addison’s disease
what can causes a raised anion gap metabolic acidosis?
lactate: shock, hypoxia
ketones: diabetic ketoacidosis, alcohol
urate: renal failure
acid poisoning: salicylates, methanol
5-oxoproline: chronic paracetamol use
what Is vesicoureteric reflux?
Vesicoureteric reflux (VUR) is the abnormal backflow of urine from the bladder into the ureter and kidney. It is a relatively common abnormality of the urinary tract in children and predisposes to urinary tract infection (UTI), being found in around 30% of children who present with a UTI.
** As around 35% of children develop renal scarring it is important to investigate for VUR in children following a UTI
what is the pathophysiology of vesicoureteric reflux?
ureters are displaced laterally, entering the bladder in a more perpendicular fashion than at an angle
therefore shortened intramural course of the ureter
vesicoureteric junction cannot, therefore, function adequately
how does vesicoureteric reflux present?
antenatal period: hydronephrosis on ultrasound
recurrent childhood urinary tract infections
reflux nephropathy
term used to describe chronic pyelonephritis secondary to VUR
commonest cause of chronic pyelonephritis
renal scar may produce increased quantities of renin causing hypertension
What investigations are performed for vesicoureteric reflux?
VUR is normally diagnosed following a micturating cystourethrogram
a DMSA scan may also be performed to look for renal scarring
what are the grades of vesicourteric reflux?
I Reflux into the ureter only, no dilatation
II Reflux into the renal pelvis on micturition, no dilatation
III Mild/moderate dilatation of the ureter, renal pelvis and calyces
IV Dilation of the renal pelvis and calyces with moderate ureteral tortuosity
V Gross dilatation of the ureter, pelvis and calyces with ureteral tortuosity
How are Voiding LUTs managed?
Voiding symptoms
conservative management - pelvic floor training, bladder training etc
moderate or severe symptoms - alpha blocker
if prostate is enlarged - 5-alpha reductase inhibitor
if prostate enlarged and moderate or severe symptoms - alpha blocker and 5-alpha reductase inhibitor
if there are mixed symptoms of voiding and storage not responding to an alpha blocker then a antimuscarinic (anticholinergic) drug may be added
How are symptoms of an overactive bladder managed?
conservative measures include moderating fluid intake
bladder retraining should be offered
antimuscarinic drugs should be offered if symptoms persist. NICE recommend oxybutynin (immediate release), tolterodine (immediate release), or darifenacin (once daily preparation)
mirabegron may be considered if first-line drugs fail
How can nocturne be managed?
advise about moderating fluid intake at night
furosemide 40mg in late afternoon may be considered
desmopressin may also be helpful
What conditions are associated with hypokalaemia due to raised serum aldosterone?
how would you differentiate these conditions
Primary hyperaldosteronism, bilateral renal artery stenosis and Bartter syndrome
Aldosterone is elevated in bilateral renal artery stenosis and Bartter syndrome due to reduced renal perfusion. Aldosterone is high in primary hyperaldosteronism due to (most commonly) an aldosterone producing adenoma.
Serum renin is usually low primary hyperaldosteronism due to the hypertension causing excessive renal perfusion.
High renin levels are seen in renal artery stenosis and Bartter syndrome as a mechanism to improve renal perfusion.
renal artery stenosis associated with HTN and may have abdominal bruits caused by turbulent flow within the stenosed arteries
Barrets syndrome is associated with normotension
what can lead to non-atherosclerotic renal artery stenosis?
Fibromuscular dysplasia
common in young woman
characteristically a string of beads appearance on angiography
how would you investigate renal vascular disease?
MR angiography is now the investigation of choice
CT angiography
conventional renal angiography is less commonly performed used nowadays, but may still have a role when planning surgery
why does alcohol binge lead to polyuria?
Alcohol causes polyuria via anti-diuretic hormone (ADH) inhibition. This leads to reduced aquaporin insertion in the collecting tubules of the nephron. This reduces water reabsorption, leading to polyuria.
what are causes of polyuria ?
Common (>1 in 10)
diuretics, caffeine & alcohol
diabetes mellitus
lithium
heart failure
Infrequent (1 in 100)
hypercalcaemia
hyperthyroidism
Rare (1 in 1000)
chronic renal failure
primary polydipsia
hypokalaemia
Very rare (<1 in 10 000)
diabetes insipidus
what may cause a false negative PSA result?
finasteride can decrease the level of serum PSA
what levels of PSA is normal ?
< 40 Use clinical judgement
40–49 > 2.5
50–59 > 3.5
60–69 > 4.5
70–79 > 6.5
> 79 Use clinical judgement
what may cause PSA levels to be high ?
benign prostatic hyperplasia (BPH)
prostatitis and urinary tract infection (NICE recommend to postpone the PSA test for at least 6 weeks after treatment)
ejaculation (ideally not in the previous 48 hours)
vigorous exercise (ideally not in the previous 48 hours)
urinary retention
instrumentation of the urinary tract
how would you differentiate between pre renal uraemia and acute tubular necrosis?
In prerenal uraemia think of the kidneys holding on to sodium to preserve volume
a low urine sodium points towards prerenal acute kidney injury
In acute tubular necrosis the urinary sodium will be high, they will respond poorly to a fluid challenge
what is acute tubular necrosis?
Acute tubular necrosis (ATN) is the most common cause of acute kidney injury (AKI) seen in clinical practice. Necrosis of renal tubular epithelial cells severely affects the functioning of the kidney.
what are the causes of acute tubular necrosis?
There are two main causes of ATN; ischaemia and nephrotoxins:
ischaemia
shock
sepsis
nephrotoxins
aminoglycosides
myoglobin secondary to rhabdomyolysis
radiocontrast agents
lead
what are the features of acute tubular necrosis?
features of AKI: raised urea, creatinine, potassium
muddy brown casts in the urine
what are the histopathological features of acute tubular necrosis?
tubular epithelium necrosis: loss of nuclei and detachment of tubular cells from the basement membrane
dilatation of the tubules may occur
necrotic cells obstruct the tubule lumen
what are the phases of acute tubular necrosis?
oliguric phase
polyuric phase
recovery phase
what is the action of calcium resonium?
Calcium resonium is a polystyrene cation exchange resin, acting to increase potassium excretion from the body through cation ion exchange. It exchanges potassium for the Ca++ in the resin.
It increases potassium excretion by preventing enteral absorption’
what are the ECG changes seen in hyperkalaemia?
peaked or ‘tall-tented’ T waves (occurs first)
loss of P waves
broad QRS complexes
sinusoidal wave pattern
What medications can be given to remove potassium from the body?
calcium resonium (orally or enema)
enemas are more effective than oral as potassium is secreted by the rectum
loop diuretics
dialysis
haemofiltration/haemodialysis should be considered for patients with AKI with persistent hyperkalaemia
what length of time is needed for an AV fistula to develop to be used?
6 to 8 weeks
What are the potential complications associated with AV fistula?
infection
thrombosis
may be detected by the absence of a bruit
stenosis
may present with acute limb pain
steal syndrome
Is Albumin-creatinine ration or protein creatinine ratio more sensitive?
CR has been found to be a more sensitive measure of small amounts of albuminuria, which can be an early sign of kidney damage in conditions such as diabetes and hypertension
An ACR of 30 mg/mmol is approximately equal to a PCR of 50 mg/mmo
what is considered as clinically important proteinuria?
3mg/mmol or more
when should you refer to a nephrologist in terms of urinary ACR?
a urinary albumin:creatinine ratio (ACR) of 70 mg/mmol or more, unless known to be caused by diabetes and already appropriately treated
a urinary ACR of 30 mg/mmol or more, together with persistent haematuria (two out of three dipstick tests show 1+ or more of blood) after exclusion of a urinary tract infection
consider referral to a nephrologist for people with an ACR between 3-29 mg/mmol who have persistent haematuria and other risk factors such as a declining eGFR, or cardiovascular disease
How is proteinuria in CKD managed?
ACEi or ARB are key in management
they should be used first line in patients with co-existent hypertension and CKD if ACR > 30. If the ACR > 70 then they are indicated regardless of the patients blood pressure
SGLT-2 inhibitors - patients who have proteinuric CKD (with or without diabetes) may benefit from treatment with SGLT2 inhibitors
how do SGLT-2 inhibitors work?
they primarily act by blocking reabsorption of glucose in the proximal tubule → lowers the renal glucose threshold → glycosuria
by blocking the cotransporter, they also reduce sodium reabsorption → natriuresis reduces intravascular volume and blood pressure, but it also increases the delivery of sodium to the macula densa → normalizes tubuloglomerular feedback and thereby reduces intraglomerular pressure
what are causes of pre-renal AKI
hypovolaemia secondary to diarrhoea/vomiting
renal artery stenosis
what causes intrinsic AKI?
relate to intrinsic damage to the glomeruli, renal tubules or interstitium of the kidneys themselves.
glomerulonephritis
acute tubular necrosis (ATN)
acute interstitial nephritis (AIN), respectively
rhabdomyolysis
tumour lysis syndrome
what causes post-renal AKI?
kidney stone in ureter or bladder
benign prostatic hyperplasia
external compression of the ureter
what is considered oliguria?
oliguria (urine output less than 0.5 ml/kg/hour)
How is AKI defined?
a rise in serum creatinine of 26 micromol/litre or greater within 48 hours
a 50% or greater rise in serum creatinine known or presumed to have occurred within the past 7 days
a fall in urine output to less than 0.5 ml/kg/hour for more than 6 hours in adults and more than
what medications should be stopped in AKI?
- NSAIDs (except if aspirin at cardiac dose e.g. 75mg od)
- Aminoglycosides
- ACE inhibitors
- Angiotensin II receptor antagonists
- Diuretics
which causes of glomerularnephritis have a low complement level?
post-streptococcal glomerulonephritis
subacute bacterial endocarditis
systemic lupus erythematosus
mesangiocapillary glomerulonephritis
what are the side effects of EPO?
accelerated hypertension potentially leading to encephalopathy and seizures (blood pressure increases in 25% of patients)
bone aches
flu-like symptoms
skin rashes, urticaria
pure red cell aplasia* (due to antibodies against erythropoietin)
raised PCV increases risk of thrombosis (e.g. Fistula)
iron deficiency 2nd to increased erythropoiesis
why may patients not respond to EPO?
iron deficiency
inadequate dose
concurrent infection/inflammation
hyperparathyroid bone disease
aluminium toxicity
what is focal segmental glomerulosclerosis\?
Focal segmental glomerulosclerosis (FSGS) is a cause of nephrotic syndrome and chronic kidney disease. It generally presents in young adults.
what are the causes of focal segmental glomerulosclerosis?
idiopathic
secondary to other renal pathology e.g. IgA nephropathy, reflux nephropathy
HIV
heroin
Alport’s syndrome
sickle-cell
what investigations would you do for focal segmental glomerulosclerosis ?
what would it show?
renal biopsy
focal and segmental sclerosis and hyalinosis on light microscopy
effacement of foot processes on electron microscopy
what are the features of HIV associated nephropathy?
massive proteinuria resulting in nephrotic syndrome
normal or large kidneys
focal segmental glomerulosclerosis with focal or global capillary collapse on renal biopsy
elevated urea and creatinine
normotension
what is diabetes insipidus?
Diabetes insipidus (DI) is a condition characterised by either a decreased secretion of antidiuretic hormone (ADH) from the pituitary (cranial DI) or an insensitivity to antidiuretic hormone (nephrogenic DI).
what are the causes of cranial diabetes Insipidus?
idiopathic
post head injury
pituitary surgery
craniopharyngiomas
infiltrative
histiocytosis X
sarcoidosis
DIDMOAD is the association of cranial Diabetes Insipidus, Diabetes Mellitus, Optic Atrophy and Deafness (also known as Wolfram’s syndrome)
haemochromatosis
what are the causes of nephrogenic diabetes insipidus?
genetic:
more common form affects the vasopression (ADH) receptor
less common form results from a mutation in the gene that encodes the aquaporin 2 channel
electrolytes- hypercalcaemia, hypokalaemia
lithium- lithium desensitizes the kidney’s ability to respond to ADH in the collecting ducts
demeclocycline
tubulo-interstitial disease: obstruction, sickle-cell, pyelonephritis
what are the features of diabetes insipidus?
polyuria
polydipsia
what are the investigations for diabetes insipidus?
high plasma osmolality, low urine osmolality
a urine osmolality of >700 mOsm/kg excludes diabetes insipidus
water deprivation test
how do you manage diabetes insipidus?
nephrogenic diabetes insipidus
thiazides
low salt/protein diet
central diabetes insipidus can be treated with desmopressin
what is membranous glomerulonephritis?
Membranous glomerulonephritis is the commonest type of glomerulonephritis in adults and is the third most common cause of end-stage renal failure (ESRF). It usually presents with nephrotic syndrome or proteinuria.
what would be seen on renal biopsy on membranous glomerulonephritis?
electron microscopy: the basement membrane is thickened with subepithelial electron dense deposits. This creates a ‘spike and dome’ appearance
what are the causes of membranous glomerulonephritis?
idiopathic: due to anti-phospholipase A2 antibodies
infections: hepatitis B, malaria, syphilis
malignancy (in 5-20%): prostate, lung, lymphoma, leukaemia
drugs: gold, penicillamine, NSAIDs
autoimmune diseases: systemic lupus erythematosus (class V disease), thyroiditis, rheumatoid
what is the management of membranous glomerulonephritis?
ACEi or ARB
Immunosuppression - if there is severe or progressive disease
steroids alone are not effective
A combination of corticosteroid + another agent such as cyclophosphamide is often used
consider anticoagulation for high-risk patients
what are causes of rapidly protective glomerulonephritis?
Goodpasture’s, ANCA positive vasculitis
Usually rapid onset, often presents as an AKI
will present with nephritic syndrome (haematuria and hypertension)
Who is IgA nephropathy commonly seen in?
typically young adult with haematuria following an URTI
there is considerable pathological overlap with Henoch-Schonlein purpura (HSP)
what may present with a mixed nephrotic/nephritic pattern?
Diffuse proliferative glomerulonephritis
classical post-streptococcal glomerulonephritis in child
presents as nephritic syndrome / acute kidney injury
most common form of renal disease in SLE
Membranoproliferative glomerulonephritis (mesangiocapillary)
type 1: cryoglobulinaemia, hepatitis C
type 2: partial lipodystrophy
what causes papillary necrosis and what are the features?
Causes
chronic analgesia use
sickle cell disease
TB
acute pyelonephritis
diabetes mellitus
Features
fever, loin pain, haematuria
IVU - papillary necrosis with renal scarring - ‘cup & spill’
what glomerulonephritides will present with nephrotic syndrome?
Minimal change disease
typically a child with nephrotic syndrome (accounts for 80%)
causes: Hodgkin’s, NSAIDs
good response to steroids
Membranous glomerulonephritis
presentation: proteinuria / nephrotic syndrome / chronic kidney disease
cause: infections, rheumatoid drugs, malignancy
1/3 resolve, 1/3 respond to cytotoxics, 1/3 develop chronic kidney disease
Focal segmental glomerulosclerosis
may be idiopathic or secondary to HIV, heroin
presentation: proteinuria / nephrotic syndrome / chronic kidney disease
what is IgA nephropathy?
IgA nephropathy (also known as Berger’s disease) is the commonest cause of glomerulonephritis worldwide. It classically presents as macroscopic haematuria in young people following an upper respiratory tract infection.
what are the associated conditions with IgA nephropathy?
alcoholic cirrhosis
coeliac disease/dermatitis herpetiformis
Henoch-Schonlein purpura
what is the pathophysiology of IgA nephropathy?
thought to be caused by mesangial deposition of IgA immune complexes
there is considerable pathological overlap with Henoch-Schonlein purpura (HSP)
histology: mesangial hypercellularity, positive immunofluorescence for IgA & C3
how does IgA nephropathy present?
young male, recurrent episodes of macroscopic haematuria
typically associated with a recent respiratory tract infection
nephrotic range proteinuria is rare
renal failure is unusual and seen in a minority of patients
how to differentiate between IgA nephropathy and post streptococcal glomerulonephritis?
post-streptococcal glomerulonephritis is associated with low complement levels
main symptom in post-streptococcal glomerulonephritis is proteinuria (although haematuria can occur)
there is typically an interval between URTI and the onset of renal problems in post-streptococcal glomerulonephritis
how is IgA nephropathy managed?
isolated hematuria, no or minimal proteinuria (less than 500 to 1000 mg/day), and a normal glomerular filtration rate (GFR)
no treatment needed, other than follow-up to check renal function
persistent proteinuria (above 500 to 1000 mg/day), a normal or only slightly reduced GFR
initial treatment is with ACE inhibitors
if there is active disease (e.g. falling GFR) or failure to respond to ACE inhibitors
immunosuppression with corticosteroids
what are markers of good vs poor prognosis in IgA nephropathy?
25% of patients develop ESRF
markers of good prognosis: frank haematuria
markers of poor prognosis: male gender, proteinuria (especially > 2 g/day), hypertension, smoking, hyperlipidaemia, ACE genotype DD
what is the tired of symptoms in haemolytic uraemia syndrome?
acute kidney injury
microangiopathic haemolytic anaemia
thrombocytopenia
what causes primary HUS?
Primary HUS (‘atypical’) is due to complement dysregulation.
what are the causes of secondary HUS?
classically Shiga toxin-producing Escherichia coli (STEC) 0157:H7
‘verotoxigenic’, ‘enterohaemorrhagic’
this is the most common cause in children, accounting for over 90% of cases
pneumococcal infection
HIV
rare: systemic lupus erythematosus, drugs, cancer
what are the investigations for HUS?
full blood count
anaemia: microangiopathic hemolytic anaemia characterised by a haemoglobin level less than 8 g/dL with a negative Coomb’s test
thrombocytopenia
fragmented blood film: schistocytes and helmet cells
U&E: acute kidney injury
stool culture
looking for evidence of STEC infection
PCR for Shiga toxins
how is HUS managed?
treatment is supportive e.g. Fluids, blood transfusion and dialysis if required
there is no role for antibiotics, despite the preceding diarrhoeal illness in many patients
the indications for plasma exchange in HUS are complicated
as a general rule plasma exchange is reserved for severe cases of HUS not associated with diarrhoea
eculizumab (a C5 inhibitor monoclonal antibody) has evidence of greater efficiency than plasma exchange alone in the treatment of adult atypical HUS
what is the most likely cause of death in patients on dialysis ?
ischaemic heart disease
