Nephrology: Nephritis Flashcards
What is poststreptococcal glomerulonephritis?
A type of glomerular nephritis that occurs after a streptococcal throat or skin infection
How soon after a streptococcal throat infection can poststreptococcal glomerulonephritis occur?
1-2 weeks
How soon after a streptococcal skin infection can poststreptococcal glomerulonephritis occur?
2-6 weeks
What is poststreptococcal glomerulonephritis caused by?
Certain strains of group A beta-haemolytic streptococci
How does poststreptococcal glomerulonephritis occur?
Immune complex deposition, neutrophil infiltration and complement activation in the glomerulus cause inflammation and/or proliferation
How do patients with poststreptococcal glomerulonephritis typically present?
Typical nephritic syndrome presentation - Sudden onset:
1) Haematuria
2) Oliguria
3) Hypertension
4) Oedema (normally periorbital due to salt retention in the loose skin)
What is a typical nephritic syndrome presentation?
Sudden onset:
1) Haematuria
2) Oliguria
3) Hypertension
4) Oedema (normally periorbital due to salt retention in the loose skin)
What are differentials/conditions that can cause a nephritic syndrome picture?
SHARP AIM
1) SLE
2) Henoch-Schönlein purpura
3) Anti glomerular basement membrane (GBM) disease (Goodpasture’s)
4) Rapidly progressive glomerulonephritis
5) Post-streptococcal glomerulonephritis
6) Alport’s syndrome
7) IgA nephropathy
8) Membranoproliferative glomerulonephritis
What is the first line investigation in patients presenting with nephritic syndrome e.g. poststreptococcal glomerulonephritis ?
1) Urinalysis
2) Urine microscopy, culture and sensitivities (MC&S)
What are typical findings in urinalysis in nephritic syndrome e.g. poststreptococcal glomerulonephritis?
Positive for protein and/or blood
What are typical findings in urine MC&S in nephritic syndrome e.g. poststreptococcal glomerulonephritis?
1) Presence of RBCs - normally dysmorphic, which suggests bleeding from the glomerulus
2) Presence of WBCs - neutrophil infiltration is one of the mechanisms of damage in nephritic syndrome) and associated casts
Which blood tests should be done in nephritic syndrome e.g. poststreptococcal glomerulonephritis and why?
1) FBC - to look for raised white cells, suggestive of an infective process
2) U&Es - can suggest AKI
Which tests can be done in nephritic syndrome e.g. poststreptococcal glomerulonephritis to help delineate an autoimmune process?
1) Immunoglobulins
2) Complement (low C3 levels normally found)
3) Autoantibodies e.g. raised anti-streptolysin titre, raised DNAse B titre
Which additional test is indicated in patients with nephritic syndrome e.g. poststreptococcal glomerulonephritis who have a fever?
Blood cultures
What is the gold standard method for diagnosis of nephritic syndrome e.g. poststreptococcal glomerulonephritis?
Renal biopsy
Which test is rarely helpful in nephritic syndrome e.g. poststreptococcal glomerulonephritis?
Imaging
How do you manage poststreptococcal glomerulonephritis?
Supportive measures
What are potential complications of poststreptococcal glomerulonephritis?
1) CKD
2) End stage renal disease
What is the most common cause of poststreptococcal glomerulonephritis?
Streptococcus pyogenes
What is an example of a streptococcal infection that can cause poststreptococcal glomerulonephritis?
Scarlet fever due to Group A beta-haemolytic streptococcus, most commonly streptococcus pyogenes
What is the most common cause of intrinsic AKI?
Acute tubular necrosis (ATN)
What is acute tubular necrosis?
Damage to the tubular epithelial cells within the renal tubules of the kidney either due to ischaemia or direct toxicity - ischaemic damage or direct toxicity to the tubular epithelial cells
How does acute tubular necrosis present?
AKI - oliguria, uraemia, electrolyte imbalance (feeling generally unwell)
What are the two types of causes of acute tubular necrosis?
Ischaemic (due to hypoperfusion) and nephrotoxic
What are ischaemic causes of acute tubular necrosis?
1) Hypotension
2) Shock - haemorrhage, cardiogenic, septic (sepsis is a common cause of hypoperfusion and ischaemia in the kidney)
3) Direct vascular injury - trauma, surgery
What are nephrotoxic causes of acute tubular necrosis?
Drugs or contrast or myoglobinuria in rhabdomyolysis
Which drugs can cause nephrotoxic acute tubular necrosis?
1) Aminoglycoside antibiotics - gentamicin
2) Antifungal drugs - amphotericin
3) Chemotherapy agents - cisplatin
4) NSAIDs
5) ACEi
6) ARB - candesartan
7) Statins
What are management options for acute tubular necrosis?
1) Correction of underlying cause e.g. fluid resuscitation
2) Removal of nephrotoxins
3) May require haemofiltration or haemodialysis
What investigation do you do to diagnosis acute tubular necrosis?
Urinalysis
What is the pathognomonic finding of acute tubular necrosis on urinalysis?
Muddy brown casts
What is glomerulonephritis?
Inflammation of the glomerulus and nephron
What are you likely to see in urinalysis in glomerulonephritis or small-vessel vasculitis?
Red-cell casts