Tubulointerstitial disorders

Question 1

Types

Answer 1

(1) ischemic or toxic tubular injury, and (2) inflammatory reactions of the tubules and interstitium (tubulointerstitial nephritis).

Question 2

Acute tubular injury

Answer 2

Acute tubular injury (ATI) is a clinicopathologic entity characterized clinically by acute renal failure and often, but not invariably, morphologic evidence of tubular injury, in the form of necrosis of tubular epithelial cells.

Question 3

Causes of ATI

Answer 3

1.Ischemia, due to decreased or interrupted blood flow, examples :microscopic polyangiitis, malignant hypertension, microangiopathies and systemic conditions associated with thrombosis (e.g., hemolytic uremic syndrome [HUS], thrombotic thrombocytopenic purpura [TTP], and disseminated intravascular coagulation [DIC]), or decreased effective circulating blood volume, as occurs in hypovolemic shock

2• Direct toxic injury to the tubules by endogenous (e.g., myoglobin, hemoglobin, monoclonal light chains, bile/ bilirubin) or exogenous agents (e.g., drugs, radiocontrast dyes, heavy metals, organic solvents)

Question 4

Mercuric chloride injury

Answer 4

injured cells may contain large acidophilic inclusions. Later, these cells become necrotic, are desquamated into the lumen, and may undergo calcification.

Question 5

Carbon tetrachloride poisoning

Answer 5

accumulation of neutral lipids in injured cell followed by necrosis.

Question 6

Ethylene glycol

Answer 6

Ethylene glycol produces marked ballooning and hydropic or vacuolar degeneration of proximal convoluted tubules.
Calcium oxalate crystals may be found