Tubular and cystic disease Flashcards
Acute tubular necrosis is a common cause of
intrinsic AKI
What causes acute tubular necrosis
Sepsis
Severe dehydration -> shock
Drugs - gentamicin
Contrast exposure
Rhabdomyolysis
What urine feature is associated with acute tubular necrosis
Oliguria
Muddy brown casts in urine
What are the histological features of acute tubular necrosis
loss of nuclei and detachment of tubular cells from the basement membrane
dilatation of the tubules
necrotic cells obstruct the tubule lumen
What is pyelonephritis
Infection of the renal pelvis
How does infection usually spread to the kidneys to cause pyelonephritis
Mostly from urinary tract
What is the most common causative pathogen of pyelonephritis
E.coli
Pyelonephritis more commonly affects male/female
Female
Why does pyelonephritis more commonly affect females
Shorter urethra = easier for bacteria to reach the kidneys
Symptoms of pyelonephritis
High fever
loin pain
nausea/vomiting
Dysuria and urinary frequency
Pain on palpation over the renal angle
Investigation for pyelonephritis
Mid-stream urine for cultures
CT
Management of pyelonephritis
Cefalexin for 7-10 days
+/- Ciprofloxacin
Review after culture results
Causes of acute interstitial nephritis
Drug toxicity
SLE
Sjogren’s
Sarcoidosis
Infection - staphylococci, Hanta virus
Most common cause of acute interstitial nephritis
Drug toxicity
What are the drugs that can cause acute interstitial nephritis
penicillin
rifampicin
NSAIDs
allopurinol
furosemide
Symptoms of acute interstitial nephritis
Delayed presentation of:
fever
rash
arthralgia
Investigations for interstitial nephritis
Bloods
Urinalysis
What is the typical blood result for interstitial nephritis
Eosinophilia
What is the typical urinalysis result for interstitial nephritis
Sterile pyuria (lots of WCC in urine)
White cell casts
Management of interstitial nephritis
Stop the drug
What are the genetic defects in autosomal dominant polycystic kidney disease
PKD1 on chromosome 16
PKD2 on chromosome 4
Which gene defect in autosomal dominant polycystic kidney disease is more common
PKD1
What does PDK1 and PDK2 code for
PDK1- polycystin-1
PDK2- polycystic-2
Which type of ADPKD has a worse prognosis
ADPKD type 1 (mutation at PDK1) - presents with renal failure earlier
Describe the pathophysiology of ADPKD
abnormal proliferation of tubular cells and changes in extracellular matrix causing large cysts to form over time
What are the renal symptoms of ADPKD
Early hypertension
Chronic pain
Haematuria - If cysts rupture, becomes infected
Fever
Renal failure
What is a classic presentation of rupture of a cyst in ADPKD
Loin pain + haematuria
What are the extra-renal symptoms of ADPKD
Hepatic cysts
Intra-cranial aneurysms
Mitral/aortic valve prolapse
Aortic regurgitation
Diverticular disease
Hernias
What is the most common extra-renal manifestation of ADPKD
Hepatic cysts
What symptoms may occur due to hepatic cysts
SOB
pain
ankle swelling
Where do the intracranial aneurysms in ADPKD usually present
junction of the anterior communicating artery and anterior cerebral artery
Investigations for ADPKD
Ab Ultrasound - screen those with family history
MRI if ultrasound is unclear
What is the diagnostic criteria of ADPKD
On ultrasound:
< 30 years - 2 cysts unilateral or bilateral
30-59 years - 2 cysts in both
> 60 years - 4 cysts in both
Management of ADPKD
Control of hypertension
Some may be eligible for tolvaptan
genetic counselling and screening other members
What is the use of tolvaptan
Can slow down progression of cysts and renal insufficiency
Who is eligible for tolvaptan
have chronic kidney disease stage 2 or 3
evidence of rapidly progressing disease
What are the complications of ADPKD
Cyst rupture
Cyst infection
CKD
Subarachnoid haemorrhage due to aneurysm
Intracerebral haemorrhage due to hypertension
Polycythaemia
What is polycythaemia
high concentration of red blood cells in your blood.
How does ADPKD lead to polycythaemia
due to increase erythropoietin production
Symptoms of polycythaemia
High haemoglobin level seen
Headache
Breathlessness
Blurry vision
Hearing problems
Splenomegaly
Autosomal recessive polycystic kidney disease most commonly affects
young children, can be perinatal/neonatal/infantile/juvenile
Where is the mutation at that causes autosomal recessive polycystic kidney disease
PKHD-1 on chromosome 6
Children with ARPKD usually
Develop into hepatic fibrosis
Have Oligohydramino consequences
Slow decline in eGFR
1/3 reach ESRF
How does ARPKD cause oligohydramino
kidney function in utero is decreased this results is lower than normal production of amniotic fluid
What are the consequences of oligohydramino
Potter syndrome
Lung hypoplasia (small, underdeveloped lungs)
When is ARPKD usually diagnosed
prenatal ultrasound or in early infancy with abdominal masses and renal failure
Kidney is always palpable
What is the typical presentation of ARPKD renal biopsy
Bilateral and symmetrical involvement
