Glomerulonephritis

  • Common form of end stage renal failure along with diabetes and hypertension
  • Group of disorders where there is damage to the glomerular filtering apparatus
  • This causes a leak of protein +/- blood into the urine depending on the disease
  • Patients may present with;
    • Haematuria
    • Proteinuria
    • Nephrotic syndrome
    • Nephritic syndrome
    • Renal failure
    • Hypertension

Tests

  • Bloods - FBC, U&Es, LFts, CRP, immunoglobulins, electrophoresis, complement (C3, C4), autoantibodies (ANA, ANCA, anti-dsDNA, anti-GBM), blood culture, anti-streptolysin O titre, HbSAg, anti-HCV
  • Urine - RBC casts, microscopy and culture and sensitivity, Bence-Jones proteins
  • 24hr urine protein
  • CXR, renal ultrasound +/- renal biopsy

 

General management

  • Refer to a nephrologist
  • Keep BP <130/80 or 125/75 if proteinuria >1g/day
  • Include an ACEI or ARB

Thin basement membrane nephropathy

  • Genetic - autosomal dominant
  • Causes persistent microscopic haematuria
  • Biopsy - thin BM via EM
  • Usually benign - small risk of CRF

Minimal change glomerulonephritis

  • Commonest cause of nephrotic syndrome in children
  • Thought to be T cell mediated
  • Associated with Hodgkin’s lymphoma and drugs
  • Causes a selective proteinuria - only small proteins are leaked out e.g. albumin
  • Renal biopsy - fusion of podocytes on EM
  • 95% of children and 70% of adults undergo remission with corticosteroids but are prone to relapse

Membranous nephropathy

  • Accounts for 20-30% of nephrotic syndrome in adults and 2-3% in children
  • Unknown cause
  • Associations - malignancy, drugs (gold, penicillamine, captopril), autoimmune disease (RA, SLE, thyroid disease), infections (HBV, syphilis, leprosy, filiariasis)
  • Usually presents with nephrotic syndrome
  • Biopsy shows diffuse thickened glomerular BM, IF shows IgG and C3 subepithelial deposits
  • Treat with corticosteroids or cyclophosphamide

Focal segmental glomerulosclerosis

  • May be primary (idiopathic) or secondary (due to reflux or IgA nephropathy, Alport’s syndrome, vasculitis, sickle cell disease or heroin use
  • Presents with nephrotic syndrome or proteinuria
  • Biopsy - some glomeruli have scarring of certain segments (focal sclerosis) IF IgM and C3 deposits in affected areas
  • 30-50% proceeds to end stage renal failure

IgA nephropathy (Berger’s disease)

  • Commonest GN in the developed world
  • Most present with macro or microscopic haematuria
  • Typically the patient is a young male with episodic macroscopic haematuria occurring a few days after URTI. Recovery is rapid between attacks
  • There is overproduction of IgA possibly due to infection which forms IC and deposits in mesangial cells

Henoch-Schonlein purpura

  • Systemic form of IgA nephropathy causing a small vessel vasculitis
  • Causes a purpuric rash on the extensor surfaces - most commonly the legs, flitting polyarthritis, abdominal colic and GN
  • Diagnosis is usually clinical but IF on the renal or skin biopsy is positive for IgA and C3

Proliferative GN

  • Chief cause is post-streptococcus GN - streptococcal antigen is deposited on the glomerulus cuasing a host reaction and IC formation
  • Usually presents with a nephritic syndrome
  • 95% recover renal functions

Mesangiocapillary glomerulonephritis

  • Rare
  • Most commonly presents with nephritic syndrome
  • Biopsy shows large glomeruli, mesangial deposits and thickened capillary walls - tramline appearance of double BM
  • There are 2 types;
    • Type 1 - subendothelial immune deposits, associated with classical complement activation. Associated with  HCV, endocarditis, visceral abscesses, infected arteriovenous shunts
    • Type 2 - intramebranous deposits sometimes with partial lipodystrophy (gaunt facial appearance)

Rapidly progressive GN

  • The most aggressive GN with potential to cause end stage renal failure over days
  • Biopsy finding of crescents affecting most glomeruli (proliferation of parietal epithelial cells and macrophages in Bowman’s capsule)
  • Causes; microscopic polyangiitis, Wegener’s granulomatosis, Goodpasteur’s disease
  • Treat with aggressive immunosuppression

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Disclaimer: These notes are my own personal study aid - DO NOT use them for medical advice!