Glomerulonephritis Flashcards
What is glomerulonephritis?
Damage to the glomerulus including glomerular basement membrane and glomerular capillaries, usually caused by inflammatory change
What are the types of glomerulonephritis?
- Membranous glomerulonephritis
- Minimal change disease
- Focal segmental glomerulonephritis
- IgA nephropathy
- Rapidly progressing glomerylonephritis
- Lupus nephritis
- Post-infectious glomerunephritis
- Anti-glomerular basement membrane antibody (anti-GBM) disease
What are the causes of glomerulonephritis?
1. Infections e.g. => group A => streptococcus, => hepatitis B and C, => respiratory & gastrointestinal tract infections, => endocarditis, => HIV
- Systemic inflammatory conditions e.g.
=> lupus,
=> rheumatoid
=> arthritis,
=> anti-glomerular basement membrane disease,
=> microscopic polyangiitis,
=> granulomatosis polyangiitis - Drugs e.g. NSAID, gold, anabolic steroids
- Metabolic disorders e.g. diabetes, hypertension and thyroid disease
- Malignancy
- Hereditary disorders e.g. Alpert’s syndrome
- Deposition diseases e.g amyloidosis
What are the signs and symptoms of glomerulonephritis?
May be asymptomatic
=> Haematuria (macro or microscopic)
=> Proteinuria
=> Oedema
=> Hypertension
=> Joint pain
=> Rash
=> Fever
=> Weight loss
What are the investigations for glomerulonephritis?
- Urinalysis
=> may show haematuria, proteinuria - Urine microscopy
- U&E
=> may show reduced GFR or elevated creatinine - FBC
=> may show anaemia or inflammatory response - Metabolic profile
=> may show underlying diabetes - Lipid profile
=> may show hyperlipidaemia - C-reactive protein
- Testing for specific systemic causes e.g. ESR, rheumatoid factor, anti-GBM antibodies
- Renal tract ultrasound
=> assess kidney size and evidence of obstruction - Renal biopsy
=> definitive test for diagnosis of glomerulonephritis
How do you treat glomerulonephritis?
- Antibiotics if infection
- ACEi to decrease proteinuria
- Corticosteroids
- Furosemide if hypertension and fluid overload
- Immunosuppressant drugs
- Plasmapheresis
How does acute glomerulonephritis present:
i) uncomplicated
ii) complicated
i) Uncomplicated: => Haematuria => Oliguria => Raised BP (50%) => Peri-orbital oedema => Fever => GI disturbance => Loin pain
ii) Complicated:
1. Hypertensive encephalopathy: => Restless => Drowsy => Severe headaches => Fits => Reduced vision => Vomiting => Coma
2. Uraemia: => Acidosis => Twitching => Stupor => Coma
- Cardiac:
=> Gallop rhythm
=> Cardiac failure ± enlargement
=> Pulmonary oedema
*produced by an immune glomerulonephritis in the kidneys
**Peak age 7 years
What investigations are carried out for acute glomerulonephritis?
- Blood test:
=> FBC, U&E (creatinine, potassium, bicarbonate, calcium, phosphate and albumin)
=> Complement (low C3, normal C4)
=> Antinuclear factors (ANA);
=> Anti-DNA antibodies (if SLE suspected);
=> Anti-neutrophil cytoplasmic antibodies (ANCA) if vasculitis suspected
=> Syphillis serology, blood cultures, virology
- Mid stream urine (MSU)
=> check urine culture & specific gravity - Throat swab
- Urgent renal ultrasound / CXR if fluid overload suspected
5.
What is post streptococcal glomerulonephritis (PSGN)?
PSGN is a type of glomerular nephritis that occurs 7-14 days after a steptococcal throat or skin infection (pharyngitis or impetigo)
What are the causes of post-streptococcal glomerulonephritis?
- Group A beta-haemolytic streptococci (Strep pyogenes)
=> Immune complex deposition (IgG, IgM, C3) in the glomeruli, neutrophil infiltration and complement activation in the glomerulus causing inflammation and/or proliferation
What are the clinical features of post-streptococcal glomerulonephritis?
- Sudden onset of gross haematuria (cola-coloured urine)
- Oliguria/proteinuria => periorbital oedema (due to salt retention in the loose skin)
- Headache / malaise / anorexia
- Hypertension
- Fever
- Abdominal pain
- Bloods: Low C3 & raised ASO titre
=> Typical nephrite syndrome presentation
What are the differentials for post-streptococcal glomerulonephritis?
SHARP AIM
=> SLE => Henoch-Schönlein purpura => Anti glomerular basement membrane (GBM) disease (aka goodpasture's disease) => Rapidly progressive glomerulonephritis => Post-streptococcal GN => Alport's syndrome => IgA nephropathy => Membranoproliferative GN
What are the investigations carried out for post-streptococcal glomerulonephritis?
- First line investigation: urinalysis and microscopy, culture and sensitivities (MC&S)
=> Urinalysis is positive for protein, blood or both.
=> Urine MC&S: presence of red blood cells (normally dysmorphic, which suggests bleeding from glomerulus), white blood cells (neutrophil infiltration is one of the mechanisms of damage in nephritic syndrome) and associated casts.
- Blood tests:
=> FBC for raised white cells, suggestive of an infective process,
=> U&Es for signs of acute kidney injury (raised urea & creatinine)
=> Immunoglobulins, complement (low C3 levels)
=> Autoantibodies i.e raised anti-streptolysin titre (confirms recent strep infection), raised DNAse B titre = an autoimmune process. - Blood cultures indicated in patients with fever.
Imaging is rarely helpful.
*The GOLD standard method for diagnosis is RENAL BIOPSY => typically not needed.
Post-streptococcal glomerulonephritis is managed conservatively.
=> Sodium restrictions => Diuretics => Anti-hypertensives => Restrict protein in oliguric phase => Give penicillin orally for 10 days => Check BP often
*Oedema lasts 5-10 days but HTN, haematuria, proteinuria may last for several weeks
Complications include:
Chronic kidney disease
End stage renal disease
*but carries a good prognosis.
What features are seen in renal biopsy?
- 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
