Glomerulonephritis

Haematuria, HTN + AKI

Haematuria can be from the lower urinary tract - red cell casts show it is from the kidney itself.

Rapidly progressive GN = serious acute form of nephritic syndrome, AKA crescentic GN (fibrous proliferation in Bowmans space causing crescents on biopsy)

Type 2 hypersensitivity (autoAbs): anti-GBM disease (Goodpasture's)

Type 3 hypersensitivity (immune complexes): post-streptococcal GN, lupus nephritis, IgA nephropathy, HSP

Pauci-immune (ANCA-associated vasculitis): GPA (Wegener's), EGPA (Churg-Strauss), MPA

AutoAbs to type IV collagen- attack GBM causing vessel damage in kidney (RPGN nephritis/nephrotic syndrome) +/- lung (pulmonary alveolar haemorrhage, SOB, Goodpasture's syndrome)

Inflammatory Sx: weight loss, malaise, fatigue, fever, chills, myalgia, arthralgia

Ix: blood (anti-GBM Abs), CXR/CT (lung involvement), renal biopsy (crescentic GN, anti-GBM on immunofluorescence)

Henoch Schonlein Purpura:

• Age 4-11
• Virus/sore throat 0-4 days earlier
• Sx: purpura, joint pain, ankle swelling, abdo pain, haematuria +/- nephritic

IgA nephropathy:

• Adult version
• Usually concurrent infection
• Kidney only
• Peak age 15-30
• Nephritic syndrome
• Mesangial deposition
• Associated HTN/CKD

Strep 10-14 days ago (sore throat/scarlet fever/skin infection)

Sx: frank haematuria +/- oedema, may also get systemic vasculitis, arthritis

Ix: anti-streptolysin O titre raised, low complement (C3), renal biopsy usually normal

Resolves spontaneously

Secondary to SLE. Mixture of nephritic and nephrotic syndrome.

Bloods: low C3, low C4 (used up complement), ANA positive, anti-dsDNA

Biopsy: IgG, complement, immunofluorescence

Lupus Sx = SOAP BRAIN MD: Serositis (pericarditis/pleuritis), Oral ulcers, Arthritis, Photosensitivity, Blood (pancytopenia), Renal (protein), ANA, Immunology (anti-dsDNA), Neurological (seizures, psych Sx), Malar rash, Discoid rash

AKA Wegener's granulomatosis

C-ANCA (PR3)

ELK: ENT, Lung, Kidney

ENT: sinusitis, epistaxis, hearing loss, stridor, saddle nose deformity

Lung: necrotising granulomas, cough, haemoptysis

Kidney: nephritis

AKA Churg-Strauss syndrome

P-ANCA (MPO)

Sx:

• asthma
• high eosinophils/IgE
• Vasculitis with granulomas: rash, paraesthesia, nephritis, lung involvement, fever, myalgia, arthralgia

Commonest cause of pulmonary-renal syndrome (haemoptysis + renal involvement)

Sx:

• No nasopharyngeal features or granulomas
• Renal failure, RPGN
• Systemic: fever, malaise, arthralgia, myalgia
• Lungs: cough, SOB, haemoptysis
• Rash
• Neuropathy

Commonest cause of pulmonary-renal syndrome (haemoptysis + renal involvement)

Sx:

• No nasopharyngeal features or granulomas
• Renal failure, RPGN
• Systemic: fever, malaise, arthralgia, myalgia
• Lungs: cough, SOB, haemoptysis
• Rash
• Neuropathy