Tubulointerstitial disorders

  1. What are tubulointerstitial disorders?
    Tubulointerstitial disorders are characterized by diseases that affect the vascular and interstitial compartments of the kidney with relative sparing of the glomeruli.
  2. What characterizes tubulointerstitial disease?
    Acute tubulointerstitial disease is characterized by pyuria, eosinophilia, eosinophiluria, and acute kidney injury.
  3. How is the diagnosis of tubulointerstitial disease established?
    Diagnosis of tubulointerstitial disease can be established in patients with slowly progressive chronic kidney disease associated with a bland urine sediment and urine protein excretion that is typically less than 2 g/24 h.
  4. What is diagnostic of analgesic nephropathy?
    A history of chronic analgesic use, elevations in the blood urea nitrogen and serum creatinine levels, and a bland urine sediment that may contain occasional granular casts or leukocytes are diagnostic of analgesic nephropathy.
  5. What are the most common causes of chronic tubulointerstitial disease in men, women, and children and young adults?
    The most common obstructive causes of chronic tubulointerstitial diseases are prostatic disease in men, cervical cancer in women, and urinary reflux in children and young adults.
  6. What correlates with risk of progression to ESKD in patients with secondary tubulointerstitial disease?
    The degree of tubulointerstitial fibrosis in patients with secondary tubulointerstitial disease correlates with the risk for progressive loss of kidney function and the development of end-stage kidney disease (ESKD) that requires kidney replacement therapy.
  7. What immunologic diseases can cause tubulointerstitial diseases?
    • Sjogren syndrome
    • Sarcoidosis
    • SLE
  8. What kidney involvement do pts with Sjogren's syndrome typically have?
    patients with Sjögren syndrome have kidney involvement that primarily manifests as tubular defects such as distal renal tubular acidosis, a decrease in urine concentrating ability, and a reduced eGFR
  9. What kind of kidney involvement do pts with sarcoidosis have?
    Approximately 25% of patients with sarcoidosis have kidney involvement that predominantly occurs as a result of tubulointerstitial disease caused by noncaseating granulomatous inflammation and fibrosis. Patients with sarcoidosis may have an elevated serum 1,25-dihydroxyvitamin D3 level that leads to hypercalcemia and hypercalciuria; these patients also may have an increased risk for nephrolithiasis and nephrocalcinosis. Furthermore, individuals with sarcoidosis and tubulointerstitial disease have polyuria and a decreased ability to concentrate and acidify the urine.
  10. What kind of kidney involvement would pts with SLE have?
    Primary tubulointerstitial disease associated with systemic lupus erythematosus (SLE) is relatively uncommon. Up to 33% of patients with SLE have interstitial inflammation and fibrosis, which may be caused by deposition of immune complexes within the interstitium.
  11. What infectious agents can cause tubulointerstitial kidney disease?
    Epstein-Barr virus, cytomegalovirus, and the polyomavirus BK virus in particular may cause progressive loss of kidney function in patients with compromised immune systems, such as kidney transplant recipients or those with HIV infection.
  12. What medications can cause tubulointerstitial kidney disease?
    • Analgesics
    • Calcineurin inhibitors
    • Lithium
  13. What combination analgesics are particularly associated with increased risk of analgesic nephropathy?
    Use of combination analgesics such as acetaminophen and aspirin with caffeine or codeine and aspirin with phenacetin is particularly associated with an increased risk of analgesic nephropathy.
  14. What kidney feature on noncontract CT is diagnostic of analgesic nephropathy?
    The presence of small, indented, calcified kidneys (SICK) also is diagnostic of analgesic nephropathy; however, these findings are usually not seen on noncontrast CT. Therefore, routine use of this study does not help to diagnose this condition.
  15. Describe lead nephropathy.
    How is lead nephropathy diagnosed?
    Lead nephropathy typically involves the proximal tubular cells and manifests as anemia and the Fanconi syndrome. Serum lead levels are an insensitive marker for lead toxicity, and calcium disodium ethylenediaminetetraacetic acid (EDTA) mobilization testing should be performed if lead nephropathy is suspected. A 24-hour urine collection of more than 600 µg/24 h (3 µmol/d) of lead is diagnostic of lead toxicity.
Card Set
Tubulointerstitial disorders
Chronic kidney disease