Renal Flashcards
Hepatic fibrosis occurs universally in which inherited renal disease?
Autosomal recessive PKD
Presentation of AR polycystic kidney disease
- Often present at birth with oligohydramnios and Potter facies, or
- Bilateral palpable enlarged kidneys
- HTN
- UTIs
- Hepatic fibrosis -> oesophageal varices
Presentation of AD polycystic kidney disease
- Often found incidentally on imaging
- May have HTN and abdominal mass (less common than ARPKD in children - usually presents later in life)
Gene causing AD polycystic kidney disease?
PKD1 gene (encoding polycystin 1) on chr 16 or
PKD2 gene (encoding polycystin 2) on chr 4
Gene causing AR polycystic kidney disease?
PKHD1 gene
Presentation of nephronopthisis?
- Polyuria
- Polydipsia
- Salt-losing nephropathy (without nephritis or nephrotic syndrome)
- Anaemia and FTT
- Extra renal manifestations incl: retinitis pigments, cerebellar aplasia with coloboma, liver fibrosis, inability to perform horizontal eye movements
Features of Bardet-Biedyl syndrome?
All the things you don’t want…
- obesity
- intellectual disability/GDD
- hypogenitalism
- extra digits (polydactyly)
- cystic dysplasia of the kidneys
- Polyuria, polydipsia and UTIs
- retinitis pigmentosa
- macrocephaly with macrotia
Most severe form of cystic renal disease?
Multicystic dysplastic kidney
- non inherited
- usually unilateral, fatal if bilateral
- causes involution of affected kidney and compensatory hypertrophy of other kidney
Embryological development of kidneys in early gestation
Pronephros (appears wk 3)
Mesonephros (appears wk 4)
Metanephros (appears wk 5) - when it appears the others regress
What does the metanephric blastema and ureteric bud form?
Metanephric blastema -> glomeruli and interstitial cells
Ureteric bud -> collecting ducts, renal pelvis and ureter
What is the triad of features in Prune Belly Syndrome?
- Abdominal muscle deficiency (“prune belly” appearance)
- Undescended testes
- Dilation of prostatic urethra, bladder and ureters
Other associations: ASD, TetOF, Imperforate anus, intestinal malrotation, poly/syndactyly
Most likely cause of incontinence if child has continuous voiding (“always wet”)?
Ectopic ureter
Which direction do testes usually twist in torsion?
Medially (so must be twisted laterally for detorsion)
What is reabsorbed in the proximal convoluted tubule?
Glucose (~100%)
Amino acids (~100%)
HCO3 (90%)
Na+ (65-80%)
Cl-
PO4
K+
H2O
Ca2+
Which diuretic acts on the proximal convoluted tubule?
Acetazolamide (carbonic anhydrase inhibitor)
What is reabsorbed in the loop of Henle?
Na+ (10-20%)
Cl-
H2O
K+
Mg++ and Ca++
Which diuretic acts on the thick ascending loop of Henle?
Loop diuretics (block the Na+/K+/2Cl- channel)
What is reabsorbed in the early distal convoluted tubule?
Na+ and Cl
(K+ and H+ are excreted)
Which diuretics act on the early distal convoluted tubule?
Thiazide diuretics (block Na+/Cl- channel)
What effect do thiazides have on urinary calcium excretion?
They reduced urinary calcium excretion (unlike loop diuretics)
Where does ADH act?
Principal cells of the collecting duct: insertion of AQ channels on apical side -> H2O reabsorption
What does aldosterone do?
In the principal cells of the CD:
- Increases epithelial Na+ channel activity
- increases Na+/K+ pump -> Na+ reabsorption, K+ secretion
In alpha intercalated cells
- Increases H+ secretion and increases HCO3/Cl pump -> HCO3 reabsorption
Which diuretics act on collecting duct?
Amiloride
Spironolactone (aldosterone antagonist)
Causes of glomerulonephritis with low complement?
PIGN (resolves within 12wks)
Membranoproliferative GN
SLE nephritis
Atypical HUS
Causes of glomerulonephritis with normal complement?
RPGN
IgA nephropathy
HSP nephritis
Granulomatosis with polyangiitis and Goodpastures
Best test for detecting recent strep infection?
Anti-DNAse B
(more sensitive and specific)
Mutation causing Alports syndrome
COL4A gene mutation encoding type 4 collagen
(Mostly X-linked inheritence)
Features of Alports syndrome
- Sensorineural hearing loss
- Renal impairment: haematuria, HTN, progressive renal impairment
- Eye: anterior lenticonus, retinal changes
- Leiomyomatosis
Urine osmolality in pre-renal AKI vs ATN?
Pre-renal AKI: >500 (ie concentrated)
ATN <350
Urine fractional excretion of Na+ (FeNa) in pre-renal AKI vs ATN?
Pre-renal AKI <1%
ATN >1%
Poor prognostic factors for Haemolytic Uraemic Syndrome?
- Anuria >2/52
- Initial neutrophil count >20
- Coma or CNS involvement
- Atypical HUS (ie diarrhoea negative)
Labs in Haemolytic Uraemic Syndrome
Anaemia
Thrombocytopenia
Blood smear: burr cells (echinocytes) - elongated or oval shaped RBCs, helmet shaped schistocytes, other fragmented RBCs
Reticulocytosis
Elevated creat
Urine: blood and protein
Elevated LDH, bilirubin, low haptoglobin
Normal coags (fibrinogen can be normal or increased)
3 features of haemolytic uraemia syndrome
- Microangiopathic haemolytic anaemia
- Thrombocytopenia
- Renal involvement (haematuria, proteinuria, elevated creatinine)
Management of complement mediated HUS?
Eculizumab (a mab to complement factor C5) may be used for complement mediated HUS or
STEC HUS with severe CNS involvement
Causes of Haemolytic Uraemic Syndrome
D+ (90%)
- Shiga toxin E coli
- Shigella
D-
- Pneumococcal
- HIV
- Complement mediated
- Drug related
WCC and white cell casts in urine think
Acute interstitial nephritis
Causes of acute interstitial nephritis
Drugs (90%)
- commonly NSAIDs, diuretics and antibiotics (penicillin, cephalosporin)
Infections (Eg Hep B, HIV, CMV)
SLE, sarcoidosis
Causes of acute tubular necrosis
- Kidney ischaemia eg due to trauma, burns, cirrhosis
- Sepsis
- Nephrotoxins eg aminoglycosides, contrast, amphotericin, cisplatin, vancomycin
Urinalysis in ATN
Muddy brown granular, epithelial cell casts, and free renal tubular epithelial cells
Indications for dialysis in acute setting
- Metabolic/ electrolyte imbalances not amendable to medical therapy eg hyperkalemia
- symptomatic uraemia (eg bleeding, pericarditis, encephalopathy)
- severe fluid overload
Management of Alport Disease
- ACE/ARB has been shown to slow progression of renal disease
What drives ultrafiltration (fluid removal) in peritoneal dialysis?
Osmotic gradient from dextrose in dialysate
What drives solute removal (clearance) in peritoneal dialysis?
Most diffusion down concentration gradient
Some via convection (“solute drag”)
Most common organisms causing peritonitis
In PD patients- staph epidermidis/ CoNS
In NS - S pneumoniae, then E coli
Side effects of tacrolimus?
Low mag
Nephrotoxicity!!
Hepatic dysfunction
Glucose intolerance
Tremors
Diarrhoea
MOA of tacrolimus
Blocks IL-2
Reduces T cell activation and proliferation
Side effects of mycophenolate?
- GI upset
- Leukopenia
- Thrombocytopenia
- Anorexia
Renal diseases that can recur after transplant and lead to graft loss?
- Membranoproliferative GN
- FSGS
- Atypical HUS
Most common form of renal stone in children
Calcium oxalate > calcium phosphate > struvite or uric acid
Inhibitors of renal stone formation
Citrate
Magnesium
Pyrophosphate
Non-nephrotic glycosuric dwarfing with hypophosphatemic rickets in early childhood
Fanconi syndrome
Congenital causes of fanconi syndrome in neonate?
- Galactosemia
- Tyrosinemia type 1
- Mitochondrial
Congenital causes of fanconi syndrome in infants?
- Cystinosis
- Fructosemia
- Lowes syndrome (X-linked)
- Fanconi-Bickel syndrome
Congenital causes of fanconi syndrome in children
- Cystinosis
- Dent’s disease (X-linked)
- Wilsons disease
How to differentiate Bartter from Gitelman syndrome
- Barrters usually presents early / perinatal whereas Gitelmans presents later (age >5)
- Gitelmans = little mag (hypomagnesemia) *though can get this with B type 4
- Hypocalciuria is seen in Gitelmans
Features of type 1 (distal) RTA?
Hyperchloremic normal anion gap metabolic acidosis
Hypokalemia
Hypercalciuria +/- nephrocalcinosis (stones)**
Elevated urine pH*
Hypokalemic metabolic alkalosis and hypetension is seen in which tubulopathy?
Liddle syndrome
What is the cause of type 2 (proximal) RTA?
Impaired HCO3- reabsorption in the PCT -> Bicarbonate wasting
Features of type 2 (proximal) RTA?
Hyperchloremic NAGMA - that doesn’t respond well to bicarb
Low urine pH (<5.5)
Low-normal K+
May be associated with Fanconi syndrome
Causes of type 2 (proximal) RTA?
Idiopathic
Fanconi syndrome
Cystinosis
Drug incl acetazolamide, 6MP, heavy metal poisoning
Features of type 4 RTA?
NAGMA
Hyperkalemia ***
hyperchloremia
Urine pH <5.5
What is the cause of type 4 RTA?C
Aldosterone deficiency or resistance (commonly due to obstructive uropathy or interstitial renal disease)
AR PKD is associated with what liver disease?
Caroli disease (dilation of biliary tree, can present with recurrent cholangitis)
What is ‘pseudohypoaldosteronism’ type 1?
A genetic condition in which there is aldosterone RESISTANCE
- aldosterone levels will be high
- hyperkalemia
- normal - low Na+
Natural history of HSP
- If renal complications develop, it usually does so in first 6 months (97%)
- First episode (without renal disease) usually resolves within 4 weeks
- Recurrence occurs in 25-35% within first 4 months
Adverse effects of cyclosporin?
Gum hypertrophy
Excess hair growth
HTN
Hepatotoxicity
Paraesthesias
Features of Fraser syndrome
Cryptopthalmos
Syndactyly
Renal agenesis or hypoplasia
Genital abnormalities eg hypospadias, cryptorchidism
What happens if BP cuff too small?
Will overestimate systolic BP (and vice versa)
Bladder width should be approx 40% of arm circumference
