TUBULOINTERSTITIAL DSES

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primarily affect the tubules and interstitium, with relative sparing of the glomeruli and renal vessels. Such disorders are conveniently divided into acute and chronic tubulointerstitial nephritis (TIN)

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most often presents with acute renal failure caused by aggressive inflammatory infiltrates that lead to tissue edema, tubular cell injury, and compromised tubular flow, or by frank obstruction of the tubules with casts, cellular debris, or crystals. flank pain due to distention of the renal capsule Urinary sediment is often active with leukocytes and cellular casts

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more indolent and may manifest with disorders of tubular function, including polyuria from o   (nephrogenic diabetes insipidus) o   leading to features of Fanconi’s syndrome (glycosuria, phosphaturia, aminoaciduria, hypokalemia, and type II renal tubular acidosis [RTA] from bicarbonaturia) o

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(type IV RTA) due to impaired ammoniagenesis, as well as progressive azotemia (rising creatinine and blood urea nitrogen [BUN]). interstitial fibrosis with patchy mononuclear cell in filtration and widespread tubular atrophy, luminal dilation, and thickening of tubular basement membranes- the predominant pathology in chronic TIN

fever, rash, peripheral eosinophilia, and oliguric renal failure occurring after 7–10 days of treatment with methicillin or another !-lactam antibiotic, is the exception rather than the rule. Atypical presentation may occurs as in NSAID-induced AIN, in which fever, rash, and eosinophilia are rare, but acute renal failure with heavy proteinuria is common : unexplained renal failure with or without oliguria and exposure to a potentially offending agent usually points to the diagnosis o Urinalysis reveals  with white blood cell casts and hematuria o Renal biopsy is NOT recommended : o Discontinuation of the offending agent o Glucocorticoid therapy may accelerate renal recovery

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systemic autoimmune disorder that primarily targets the exocrine glands, especially the lacrimal and salivary glands, and thus results in symptoms, such as dry eyes and mouth, that constitute the “ ”

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 is the most common renal manifestation can be associated with distal RTA, nephrogenic diabetes insipidus, and moderate renal failure. Diagnosis is strongly supported by positive serologic testing for . : , although patients may require maintenance therapy with azathioprine or mycophenolate mofetil to prevent relapse

systemic autoimmune disease of  etiology affects more than male median age of onset: , often bilateral and accompanied by blurred vision and photophobia Clinical symptoms are typically self-limited in children, but are more apt to follow a relapsing course in adults. : , although maintenance therapy with agents such as methotrexate, azathioprine, or mycophenolate may be necessary to prevent relapses

interstitial mononuclear cell inflammatory reaction often accompanies the glomerular lesion in most cases of class III or IV lupus nephritis, and deposits of immune complexes.

: more chronic inflammatory infiltrate with granulomas and multinucleated giant cells.   should be ruled out before starting treatment because this too is a rare cause of granulomatous interstitial nephritis.

characterized by a dense inflammatory infiltrate containing IgG4-expressing plasma cells presents with autoimmune pancreatitis, sclerosing cholangitis, retroperitoneal fibrosis, and a chronic sclerosing sialadenitis   have been successfully used as first-line treatment

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patients present with typical clinical and histologic features of AIN but have no evidence of drug exposure or clinical or serologic features of an autoimmune disease responsive to

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most often seen in immunocompromised patients, particularly renal transplant recipients with reactivation of polyomavirus BK

- often accompanied by flank pain from tubular obstruction, may occur in patients treated with  for toxoplasmosis,  for HIV, and  for severe herpesvirus infections. o sulfonamide crystals, individual or parallel clusters of needle- shaped indinavir crystals, or red-green birefringement needle-shaped crystals of acyclovir. adverse effect is generally precipitated by

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  in tubular cells and interstitium may lead to permanent renal dysfunction in patients who survive ethylene glycol intoxication is an uncommon but serious complication of oral Phospho-soda used as a laxative or for bowel preparation for colonoscopy

—should be considered in patients who fail to recover when the precipitating factor is corrected or in any elderly patient with otherwise unexplained acute renal failure. filtered monoclonal immunoglobulin light chains o ( ) form intratubular aggregates with secreted   in the distal tubule : Clinical clues to the diagnosis include anemia, bone pain, hypercalcemia, and an abnormally narrow anion gap due to hypoalbuminemia and hypergammaglobulinemia : goals of treatment are to correct precipitating factors such as hypovolemia and hypercalcemia, discontinue potential nephrotoxic agents, and treat the underlying plasma cell dyscrasia

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Interstitial infiltration by malignant B lymphocytes is a common autopsy finding in patients dying of chronic lymphocytic leukemia and non-Hodgkin’s lymphoma » »

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often the result of renal ischemia or secondary to a primary glomerular disease important forms of CIN are the result of developmental anomalies or inherited diseases such as reflux nephropathy or sickle cell nephropathy and may not be recognized until adolescence or adulthood »

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consequence of vesicoureteral reflux (VUR) or other urologic anomalies in early childhood  often goes unnoticed until early adulthood when chronic kidney disease is detected during routine evaluation

Evidence of tubular injury may be evident in childhood and early adolescence in the   due to decreased concentrating ability or type IV renal tubular acidosis

potential mechanisms by which glomerular disease might cause tubulointerstitial injury include  leading to downstream tubulointerstitial ischemia, especially in the case of glomeruli that are globally obsolescent due to severe glomerulonephritis.

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adults are frequently , but may give a history of prolonged bed-wetting or recurrent UTIs during childhood, and exhibit variable renal insufficiency, hypertension, mild to moderate proteinuria, and unremarkable urine sediment. Treatment: o Maintenance of sterile urine in childhood has been shown to limit scarring of the kidneys o Aggressive control of blood pressure with an angiotensin-con- verting enzyme inhibitor (ACEI) or angiotensin receptor blocker (ARB) and other agents is effective in reducing proteinuria

results from the long-term use of compound analgesic preparations containing phenacetin, aspirin, and caffeine characterized by renal insufficiency, papillary necrosis, attributable to the presumed concentration of the drug to toxic levels in the inner medulla, and a radiographic constellation of best appreciated by computed tomography Patients may also have  due to impaired concentrating ability and   from tubular damage. Shedding of a sloughed necrotic papilla can cause  due to ureteral obstruction

Chinese herbal nephropathy and Balkan endemic nephropathy  of AAN requires two of the following three features: characteristic histology on kidney biopsy confirmation of aristolochic acid ingestion; and detection of aristolactam-DNA adducts in kidney or urinary tract tissue.

unusual form of slowly progressive chronic kidney disease with mild proteinuria, interstitial fibrosis, tubular atrophy, and oddly enlarged nuclei of proximal tubular epithelial cells. It has been linked to mutations in

nephrogenic diabetes insipidus- most common renal sequelae of lithium salt intake manifesting as polyuria and polydipsia Lithium accumulates in principal cells of the collecting duct by enter- ing through the epithelial sodium ch annel (ENaC), where it inhibits glycogen synthase kinase 3 !  and downregulates vasopressin-regulated aquaporin water channels  include interstitial fibrosis and tubular atrophy that are out of proportion to the degree of glomerulosclerosis or vascular disease, a sparse lymphocytic infiltrate, and small cysts or dilation of the distal tubule and collecting duct that are highly characteristic of this disorder.

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amiloride to inhibit lithium entry via ENaC has been effective to prevent and treat lithium-induced nephrogenic diabetes insipidus most prudent approach is to monitor lithium levels frequently and adjust dosing to avoid toxic levels (preferably