Interstitial nephritis
From IDWiki
Etiology
Drugs
- Nonsteroidal antiinflammatory agents (NSAIDs)
- Includes selective cyclooxygenase (COX)-2 inhibitors and mesalamine
- Antimicrobials
- Penicillins and cephalosporins
- Rifampin
- Trimethoprim-sulfamethoxazole
- Ciprofloxacin
- Indinavir
- Diuretics, including furosemide and thiazides
- Cimetidine
- Allopurinol
- Proton pump inhibitors (PPIs)
Infections
Long list, including Legionella, Leptospira, cytomegalovirus (CMV), Streptococcus, Mycobacterium tuberculosis, Corynebacterium diphtheriae, Epstein-Barr virus (EBV), Yersinia, polyomavirus, Enterococcus, Escherichia coli, adenovirus, and Candida.
Autoimmune Disorders
- Systemic lupus erythematosus
- Sarcoidosis
- Sjögren syndrome
- IgG4 disease
Clinical Manifestations
- Can be asymptomatic, presenting with renal dysfunction
- Nausea, vomiting, malaise, and oliguria
- May have arthralgias
- With drug-induced AIN, can have an allergic syndrome that includes fever, eosinophilia, and rash
Investigations
- Creatinine, showing AKI
- CBC, showing eosinophilia
- Urine studies
- May have pyuria and white cell casts and RBCs, and eosinophiluria
- Usually around 1 g/day of proteinuria
- FENa >1%