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Currently filtering by tag: Tubulointerstitial disease

Art of Medicine: Anti-Brush Border Antibody Disease

The above painting shows massive tubular basement membrane (electron dense on EM) deposits along proximal tubules with sparing of the distal tubules.  This is a finding that can be seen by electron microscopy in anti-brush border antibody disease (ABBA).   Tubular basement membrane deposits are also seen in lupus nephritis (all classes), IgG4-associated kidney disease, idiopathic hypocomplementemic interstitial nephritis, polyomavirus nephritis (BK virus or JC virus), or in response to certain medications (eculizumab, NSAIDS, and others).   Interstitial inflammation is not prominent in ABBA disease, as it is with other pathologies with tubular basement membrane deposits (such as IgG4-associated disease, drug reactions,...

Chronic Uric Acid Nephropathy

Chronic uric acid nephropathy results from deposition within the renal parenchyma of monosodium urate monohydrate. While the disease may occur in the setting of increased uric acid production, it is overwhelmingly more common in the setting of decreased uric acid excretion. Histologically, chronic uric acid nephropathy is characterized by the presence of tubulointerstitial microtophi within the renal medulla, associated with interstitial fibrosis and inflammation. Microtophi are deposits of monosodium urate crystals surrounded by giant cells, epithelioid histiocytes and lymphocytes, which may have a radial needle-like cleft (Fig 1 – blue arrow; Fig 2) or amorphous morphology (Fig 1 – orange...

Granulomatous Interstitial Nephritis Differential

This biopsy is from a 25-year-old African American female with renal failure. The photomicrographs here show renal involvement by non-caseating granulomas eliciting the diagnosis of granulomatous interstitial nephritis. The patient was found to be hypercalcemic and to have hilar lymphadenopathy and reticulonodular infiltrates on chest x-ray and was diagnosed with sarcoidosis. A case series examining 46 cases of granulomatous interstitial nephritis (GIN) by Bijol et al (ref below) found the most common etiology (45%) of this pattern to be a drug-induced reaction. This was followed by sarcoidosis (29% of GIN), other (including infection) at 16% and there were 10% of...

IgG4-Related Tubulointerstitial Nephritis

IgG4-related disease is a systemic inflammatory and sclerosing disorder which may affect a wide range of different organs including the pancreas, salivary glands, lacrimal glands, lungs, blood vessels, lymph nodes, thyroid and kidneys among others. Patients may have multisystemic disease at the time of presentation, or different organs may progressively become involved over time. While the renal involvement may have different histopathologic patterns of injury, by far the most common is in the form of acute or chronic tubulointerstitial nephritis (IgG4-related tubulointerstitial nephritis). The renal biopsy shown (Fig 1-4) is from a 35-year-old male with a history of lymphadenopathy and...

Armanni Ebstein Lesion

Armanni-Ebstein lesion, originally described by Luciano Armanni in 1872, is characterized by vacuolization and PAS-positive glycogen accumulation within the cytoplasm of tubular epithelial cells (Fig 1). The cytoplasm of these cells stains pale on PAS following diastase digestion (Fig 2). These changes predominantly involve the terminal straight portion of the proximal convoluted tubule and are usually seen in the outer renal medulla. Armanni-Ebstein lesions have been mostly described in poorly controlled diabetics and patients with diabetic ketoacidosis; however, similar lesions have been reported in patients with Fanconi Syndrome and alcoholic ketoacidosis.  Of note, while not the original description, the term...

Brush Border

Dr. Bourne brings us today's Teaching Point! Do you know how the proximal tubule brush border is related to the Nobel Prize in Chemistry? Normal proximal tubules have a prominent apical brush border which is highlighted by periodic acid Schiff (PAS) staining. One clue, in fact, to the presence of tubular injury is the loss of this brush border PAS positivity. The ultrastructural correlate of this brush border is the individual microvilli that extend into the tubular lumen from the apical surface of the cell (Fig 2). These microvilli greatly amplify the cell surface area in contact with the luminal ultrafiltrate,...

Pushing Glass (September 20, 2017)

The patient is a 65-year-old African American female who presents with a protein/creatinine ratio of 2 and a serum creatinine of 3.5 mg/dl. Serologies for ANA, dsDNA, c-ANCA, p-ANCA, and rheumatoid factor are negative. On CT examination, she has several enlarged peribronchial lymph nodes. Her ACE level is elevated. What is the best diagnosis? A. Necrotizing Vasculitis. B. Acute Interstitial Nephritis Concerning for a Drug Reaction. C. Granulomatous Interstitial Nephritis Concerning for Sarcoidosis. D. ANCA-associated Vasculitis with Diffuse Crescents. The correct answer is c: Granulomatous Interstitial Nephritis Concerning for Sarcoidosis. The biopsy shows a florid example of non-caseating granulomas throughout...

Diagnose This! (September 18, 2017)

What is your diagnosis?     ​   ​ ​   ​   ​ ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​   ​ ​   ​ ​   ​ ​   ​ ​     ​   ​   ​...

Chronic Active Tubulointerstitial Nephritis

Chronic tubulointerstitial nephritis in children may be secondary to a number of possible etiologies such as drug and other exogenous toxin exposure, infections, lower urinary tract obstruction, autoimmune diseases, nephronophthisis and genetic disorders such as autosomal dominant tubulointerstitial kidney disease due to MUC1, UMOD, REN or HNF1β. Figures 1-3 are representative images from the kidney biopsy of a 15 month old male with a history of prune belly syndrome, status post multiple lower urinary tract procedures and recurrent urinary tract infections. There is severe tubulointerstitial scarring which is disproportionate to the degree of glomerulosclerosis, with a moderate, predominantly chronic, interstitial...

Chronic Active Tubulointerstitial Nephritis

39 y/o male presents with acute kidney injury, creatinine 3.5 mg/dl. Bland urinalysis, serologic studies negative. Immunofluorescence study of the renal biopsy was negative for all stains. EM showed no deposits and was otherwise unremarkable. 1. Tubulointerstitial nephritis (H&E x100). 2. Lymphocytes, plasma cells, neutrophils and eosinophils (H&E x400). 3. Interstitial inflammation and fibrosis (Trichrome x100) 4. Intact glomerulus (PAS x400). Diagnosis: Chronic Active Tubulointerstitial Nephritis Comment: Most likely drug-induced but other causes include Sjogren’s syndrome, tubulointerstitial nephritis with uveitis (TINU), Behcet’s syndrome, sarcoid among others. Further discussion with the clinician after giving the above pathologic diagnosis: “Oh, that fits...