May 3, 2016 - Acute Interstitial Nephritis

Question 1

Types of Interstitial Nephritis

Answer 1

There is acute interstitial nephritis and chronic interstitial nephritis.

Question 2

Acute vs Chronic Interstitial Nephritis

Answer 2

Acute interstitial nephritis (AIN) has a rapid loss of renal function, has marked interstitial infiltrate/edema, and accounts for ~10% of AKI.

Chronic interstitial nephritis (CIN) has an indolent course of action, has interstitial fibrosis and tubular atrophy, and leads to CKD.

Question 3

Pathogenesis of Acute Interstitial Nephritis

Answer 3

An immune mediated process.

Cellular immunity is most important, not antibodies. T-cells and monocytes infiltate the interstitial compartment of the kidney.

Question 4

Causes of Acute Interstitial Nephritis

Answer 4

Drugs (70%)

Beta-lactam antibiotics

Other antibiotics

NSAIDs

Infections (15%)

Autoimmune (5%)

Question 5

Investigations of AIN

Answer 5

Urine - pyuria (eosinophils), hematuria, WBC casts

Blood - eosinophilia, electrolyte disorders

Question 6

AIN Treatment

Answer 6

Stop the offending drug

Prednisome 1 mg/kg for 7-14 days if no improvement

Prognosis for recovery is good

Question 7

Chronic Interstitial Nephritis Causes

Answer 7

Drugs - lithium, calcineurin inhibitors

Toxins - lead, chinese herbs

Autoimmune - sarcoidosis, TINU

Malignancy - multiple myeloma

Vascular - atheroembolic disease

Identify these to stop the progression to CKD.