W2L5 Tubulointerstitial Nephritis

Question 1

Definition Tubulointerstitial nephritis?

Answer 1

• AIN: char by acute, often reversible disease char by inflammatory infiltration of kidney interstitium by inflammatory cells, leading to non-oliguric/ oliguric AKI
• Chronic TIN: Less frequently, interstitial inflammation can lead to chronic changes, with subsequent development of CKD

Question 2

Etiology Acute TIN?

Answer 2

1. Infectious
   - viral,bacterial,fungal
2. Immune- mediated
   - SLE
3. Idiopathic
4. Drugs
   - Antimicrobe, NSAIDs, diuretic

Question 3

Clinical presentation AIN?

Answer 3

1. Renal manif
   - Hx drug intake
   - non-oliguric AKI.
   - Non nephrotic proteinuria, pyuria
   - Flank pain
2. Extra-renal
   - Classic triad(fever, eosinophilia & rash)
   - Fatigue, Myalgias, arthralgias

Question 4

Investigations AIN?

Answer 4

• Urine analysis: sterile pyuria, WBCs casts, hematuria, proteinuria
• Sr creatinine & electrolytes
• ABG: metabolic acidosis
• US: normal size/enlarged kidneys
• Renal biopsy

Question 5

Treatment AIN?

Answer 5

• Stop the offending drug
• Treatment of the cause
• Correct electrolyte & acid base
• Steroids: 1mg/kg/d prednisolone (max 60 mg/d)

Question 6

Chronic TIN?

Answer 6

• Progression ATIN over time
• US: small echogenic kidneys
• Ttt as CKD case