5. Infective and Inflammatory Tubulo-Interstitial Kidney Diseases Flashcards
How can acute pyelonephritis be seen on histology?
Pus cells in lumen of tubule
Preferentially infecting poles
Heals by fibrosis
What is chronic pyelonephritis?
Repeated acute infections causing fibrosis or a continued episode of acute pyelonephritis
Can cause end stage kidney disease in children
What can be seen on histology in chronic pyelonephritis?
Acute and chronic inflammation Thyroidisation of tubules Glomerular hypertrophy and FSGS as scarring causes increased workload on remaining nephrons Thickening of vascular walls Struvite stones
What does thyroidisation mean?
Tubules become filled with proteinaceous fluid
What are struvite stones made of and how is their shape commonly described?
Ammonium phosphate
‘Staghorn’ as they hold the shape of the collecting system
What are less common appearances of chronic pyelonephritis?
In xanthogranulomatous pyelonephritis there is an accumulation of foamy macrophages
Malakoplakia there are eosinophilic macrophages
What are the main causes of acute tubulointerstitial nephritis?
Hypersensitivities (2, 3, 4) to drugs
Lupus, sjogrens, uveitis, sarcoid
Familial
What drugs can cause acute tubulointerstitial nephritis?
PPIs
Antibiotics
NSAIDs
TNF inhibitors
What is seen on histology in acute tubulointerstitial nephritis?
Eosinophils in interstitium
What are the causes of hydronephritis?
Congenital obstruction eg. lacking neuromuscular function in ureter
Tumours
Calculi
Obstruction from outside
How does hydronephritis affect the appearance of the kidney?
Dilatation of renal pelvis and calyces
Flattened papillae
Atrophy of renal cortex
What effect does one kidney with hydronephritis have?
Lose kidney and increased BP
What are the results of bilateral hydronephritis?
Patient needs dialysis or will die
What are oxalate stones produced from?
Ethylene glycol antifreeze ingestion
Malabsorption
What is one way oxalate stones can be differentiated form others?
Colourful under polarised light
Which patient group is most likely to get kidney stones?
Men in 20s-30s
What are the types of kidney stones?
Majority are calcium
Magnesium ammonium phosphate ie struvite in infections
Uric acid a/w gout
Cysteine
What percentage of gallstones vs kidney stones are visible on x ray?
10% of gallstones
90% of kidney stones
What are the clinical features of renal calculi?
Renal colic
Haematuria
Pyelonephritis
Hydronephritis
What is the treatment for renal calculi?
Lithotripsy: ablation with ultrasound beams
Rehydration if calcium stones
What is acute renal failure?
Increase in serum creatinine and loss of glomerular filtration over a week
What is the clinical course of acute renal failure?
Fatal without dialysis
Recovery requires regeneration of tubule epithelial cells: 3-21 days
Chronic renal failure occurs if it lasts >6-8 weeks
What are the pre-renal causes of acute renal failure?
All types of shock: hypovolaemia, CCF, sepsis
Hepatorenal syndrome
Bilateral renal artery stenosis
NSAIDs
What are the renal causes of acute renal failure?
Acute glomerulonephritis Vascular: ANCA vasculitis, thrombosis, emboli Tubulointerstitial nephritis Acute tubular necrosis Obstruction to tubules within kidney
What is an example of obstruction to tubules within the kidney?
Myoglobin in a crush injury
What are the post renal causes of acute renal failure?
Any cause of urinary tract obstruction
On urinalysis, what does dysmorphic RBCs suggest?
Glomerulonephritis
On urinalysis, what does non dysmorphic RBCs suggest?
Calculi
Tumour
Infection
On urinalysis, what does WBCs suggest?
Tubulointerstitial nephritis
On urinalysis, what does granular casts suggest?
Acute tubular necrosis
On urinalysis in acute renal failure, what does normal urine suggest?
Pre or post renal causes
What description is given to thrombotic lesions caused by malignant hypertension?
Onion-skin lesions
