Interstitial nephritides
Tubulointerstital nephritis
- Inflammation of the renal interstitium, it may be acute or chronic
Acute tubulointerstial nephritis
- Is mediated by an immune reaction to mediactions, infections and other causes
- Drugs;
- NSAIDs
- Antibiotics - cephalosporins, penicillins, sulphonamides, rifampicin
- Diuretics - furosemide, thiazides
- Also - allopurinal, cimetidine, amphotericin
- Infections
- Staph, Strep, Brucella, Leptospira
- Immune disorders
- SLE, GN
- May present with renal impairment, hypertension or acute renal failure
- Systemic features include fever, rash, arthralgia, eosinophilia, uvetitis, raised IgE
- Treatment
- Stop cause
- Prednisolone 1mg/kg
- Most have full recovery of renal function
Chronic tubulointerstital nephritis
- Results from many disorders leading to extensive fibrosis and tubular loss on renal biopsy
- Patients present with chronic renal failure
- Causes;
- Chronic pyelonephritis
- Sickle cell disease
- Lead or cadmium intoxification
Analgesic nephropathy
- Associated with prolonged heavy ingestion of compound analgesics - NSAIDs, paracetamol
- Leads to interstitial nephritis and papillary necrosis
- Presents with sterile pyuria, UTI, symptoms of chronic renal failure or hypertension
Urate nephropathy
- Acute crystal nephropathy
- Occurs when insoluble uric acid crystals deposit causing blockage of the tubules
- Mainly caused by excessive uric acid caused by cell lysis during chemotherapy
- Plasma urate is often raised and there is birefringent crystals on microscopy
- Treatment
- Good hydration
- Allopurinal pre-chremotherapy
- Urinary alkalinization with sodium biocarbonate (uric acid is more soluble in alkaline conditions)
- Chronic crystal nephropathy
- Whether is it associated with gout is debatable but it is associated with Lesch-Nyhan syndrome
- Treat with allopurinol