Tubulointerstitial Diseases of the Kidney

• Primary tubulointerstitial diseases of the kid­neyare characterized by abnormalities of struc­ture and function of tubules and the interstitium.
• The glomeruli and renal vasculature are involved to a Jesser extent.
• The biopsy specimens and the urine sediments do not help in diagnosis.
• Acute interstitial nephritis (AIN) is most often induced by drug therapy

Treatment of Tubulointerstitial Diseases

In proximal tubule dysfunction

• there is hypokale­mia, glycosuria, phosphaturia, uricosuria,
• bicarbonaturia, aminoaciduria, like in proximal or type 11 renal tubular acidosis (RTA).
• The proteinuria is usually less than 2 gjday.
• These findings are called the Fanconi syndrome.
• There is hyperch/oremic metabolic acidosis and urine pH is less than 5.3.
• There is a reduce,d excretion of ammonia.
• There may be no turia and polyuria as in analgesic nephropathy and sickle cell disease.

Causes of acute interstitial nephritis

•   Acute interstitial nephritis may be caused by beta lactam antibiotics, sulphonamides, quinoiones, vancomycin, erythromycin, rifampicin, ethambu­tol, acyclovir.
•   Non steroidal antiinflmmatory drugs.
•   Diuretics – thiazides, frusemide, triamterene.
•   Anticonvulsants – Phenytoin, phenobarbitol, carbamazepine.
•   Captopril, Omeprazoie, Allopurinol.
• Infections (bacteria) – Streptococcus, staphylo­coccus, salmonella, brucella.
• Viruses – Epstein Barr virus, Cytomegalovirus,
• HIV.
• Leptospira, Rickettsia, Mycoplasma.
• Sarcoidosis.
•   Antitubule basement membrane disease.

Causes of chronic tubulo interstitial diseases

• 1. Polycystic kidney
• 2. Medullary sponge kidney
• 3. Analgesic nephropathy
• 4. Lead nephropathy
• 5. Hyperuricemia
• 6. Hypercalcemia
• 7. Hypokalemia
• 8. Fabry’s disease
• 9.. Sjogren’s syndrome
• 10. Leukemia
• 11. Multiple myeloma
• 12. Sickle cell disease
• 13. Chronic pyelonephritis
• 14. Radiation nephritis.

Treatment of Tubulointerstitial Diseases

• Treatment is management ofthe presenting feertures, withdrawal of the offending drug or agent, treatment of the etiology, dialysis, and renal transplant.