Chronic interstitial nephritis Flashcards
What is chronic interstitial nephritis
A Histologically defined condition of the kidney
Tubular atrophy, fibrosis, loss
Chronic lymphocytic infiltration
Interstitial fibrosis
Slow, progressive disease course, which will eventually cause glomerular and vascular damage to the kidney.
15-30% go to ESRD
Causes of chronic interstitial nephritis
Drugs:
- most often analgesics, NSAIDs
- lithium, cyclosporin,
Autoimmune diseases:
- SLE
- Sjogren’s syn.
Toxins:
heavy metals, mercury
aristolochic acid, an herb, balkan nephropathy
Chronic urinary tract obstruction,
Chronic vesicoureteral reflux,
Hydronephrosis
Acute Pyelonephritis
Hematologic diseases, Myeloma and Light Chain Nephropathy.
Irradiation
Chronic transplant rejection
Chronic hypercalcemia, hyperuricemia, hypokalemia
Symptoms and presentation of Chronic interstitial nephritis
Asymptomatic, slow decline of kidney function over many years.
Possible presentations:
1) Patient often presents for the first time with end-stage kidney disease. MAD HHHHUNGER
2) Polyuria and DI
3) Renal diabetes insipidus, and inability to concentrate urine, from medullary fibrosis and impaired permeability of the collecting ducts. ADH resistance.
4) Fanconi syndrome
5) Renal tubular acidosis
Hypertension commonly comorbid, but not always
Urine:
Sterile pyuria, Leukocyte casts with no infection or pus.
Hematuria
mild tubular proteinuria, below nephrotic range. from low and medium mw proteins, immunoglobulins, beta-2 microglobulin, a1 microglobulin.
negative albumin dipstick is common.
Fanconi syndrome
Generalized impairment of proximal tubule function.
impaired glucose, amino acid, small protein, phosphate, and urate reabsorption.
- Non-diabetic glucosuria and polyuria, polydipsia
- Phosphaturia, phosphate wasting and hypophosphatemia
- Tubular proteinuria, no albuminuria but elevatred PCR ratio.
- Hypouricemia
Treatment:
Replace phosphate to prevent bone demineralization.
