Type IV hypersensitivity reaction against tubules/interstitium
IT IS NOT acute tubular necrosis (ATN) - direct epithelial damage due to toxins/ischaemia
Causes/Factors
- Medications: Certain medications, such as nonsteroidal anti-inflammatory drugs (NSAIDs), antibiotics, and proton pump inhibitors (PPIs), can trigger an immune response leading to inflammation.
- Infections: Bacterial, viral, and fungal infections can cause tubulointerstitial nephritis.
- Autoimmune Disorders: Conditions like systemic lupus erythematosus (SLE) and Sjogren’s syndrome can lead to inflammation in the kidney.
- Toxins: Exposure to certain toxins and heavy metals can damage kidney tubules.
- Idiopathic: In some cases, the exact cause may not be identified.
Symptoms
Symptoms of tubulointerstitial nephritis can vary and may include:
- Fatigue: Generalized tiredness and weakness.
- Reduced Urine Output: Decreased urine production.
- Swelling: Edema, particularly around the eyes, hands, and feet.
- Frequent Urination: Increased need to urinate, especially at night.
- Blood in Urine: Hematuria (blood in the urine) may be present.
Signs
- Fluid Retention: Visible edema and swelling.
- Reduced Urine Output: Decreased frequency and volume of urination.
Diagnostic Tests
Diagnosing tubulointerstitial nephritis involves several tests:
- Urinalysis: Detects abnormalities in the urine, including blood and protein.
- Blood Tests: Assess kidney function, levels of waste products, and inflammation markers.
- Kidney Biopsy: Removal and examination of a kidney tissue sample to determine the cause and extent of inflammation.
Management
Treatment of tubulointerstitial nephritis depends on the underlying cause:
- Discontinuation of Causative Agents: If medications are the cause, discontinuing the offending drugs.
- Infection Treatment: Treating underlying infections with appropriate medications.
- Immunosuppressive Therapy: For cases related to autoimmune disorders.
- Supportive Care: Managing symptoms and promoting kidney health.
- Diet and Fluid Management: Adjusting salt and fluid intake.
Complications/Red Flags
- Chronic Kidney Disease: Prolonged inflammation can lead to kidney damage and impaired function.
- Acute Kidney Injury: Sudden and severe kidney dysfunction may occur.
- Recurrence: Tubulointerstitial nephritis can recur if underlying causes are not adequately addressed.