Kidney

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Kidney
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• Vascular diseases of Kidney
• 1.Hypertensive Renal Disease
• Nephrosclerosis-Benign Malignant
• 2.Thrombotic Microangiopathies
• Childhood Adult Hemolytic-Uremic Syndrome (HUS)
  
• Adult (female) Thrombotic Thrombocytopenic
  Purpura (TTP)
• Autoimmune Diseases
• Toxemia of pregnancy
• Severe bacterial infections.
• 3.Renal Artery Stenosis (RAS)
• Atherosclerotic or Fibromuscular dysplasia
• reversible hypertension
• 4.Renal Infarcts
• Embolic or Thrombotic.

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• 1. Hypertension
• Most renal diseases cause HTN
• HTN has marked effects on the kidneys
• Benign Nephrosclerosis hyaline arteriosclerosis
• Most are at risk for developing malignant
  hypertension
• Malignant Nephrosclerosis Hyperplastic
  arteriolosclerosis
• Fibrinoid necrosis of arterioles
• Thrombotic Microangiopathy (Necrotizing
  Glomerulitis)
• ? renal blood flow therefore, ? renin
  -angiotensin system ? ?BP ? hypertension.
• Clinical
• Neurological Disoriented ? coma
• Eyes Papilledema
• Renal proteinuria, Hematuria RF

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Benign Nephrosclerosis

• Fine leathery granularity,

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Benign Nephrosclerosis

• Hyaline change in small blood vessels

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Malignant Nephrosclerosis

• Hyperplastic arteriolosclerosis (onion-skinning)
• Blood vessels have collagen deposits making the
  onion skinning appearance
• Notice how lumen gets very small

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• 2. Thrombotic Microangiopathies
• Common findings
• Thrombosis in small vessels
• Microangiopathic hemolytic anemia (MHA)
• Thrombocytopenia
• Pathogenesis
• Endothelial injury ? platelet aggregation?
  thrombosis
• Vasoconstriction ? ischemia ? necrosis
• A) Childhood Hemolytic Uremic Syndrome (HUS)
• E. coli (infected Hamburgers)
• Clinical renal failure is prominent
• Intestinal bleeding, oliguria, Hematuria, MHA,
  HTN
• B) TTP young females with High mortality

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Fibrin Thrombi (Childhood HUS)

• Caused by DIC, HUS (E. coli 0157H7)

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3. RENAL ARTERY STENOSIS (RAS)
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Fibromuscular Dysplasia

• Fibromuscular dysplasia

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• 4. Renal infarcts
• Branches of Renal artery - End arteries.
• MCC MI and thromboembolism from Atrial
  Fibrillation
• Clinical
• Asymptomatic or
• Large unilateral -May cause HTN
• Extensive bilateral -May cause RF

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Renal Infarcts
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Renal Infarcts
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Kidney
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• Tubulo Interstitial diseases
• 1. Acute Tubular Necrosis (ATN)
• 2. Pyelonephritis (PN)
• Acute
• Chronic
• 3. Acute drug-induced Interstitial Nephritis
• 4. Analgesic Abuse Nephropathy
• 5. Metabolic Tubulointerstitial Disease
• Urate
• Hypercalcemia
• Multiple Myeloma

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• 1. Acute Tubular Necrosis (ATN)
• Most serious but reversible kidney disease,
• Causes next slide
• Pathology destruction of tubular epithelial
  cells ?Acute suppression of renal function,
  urinary output lt400 ml/day
• ATN ?ARF by mechanisms
• Tubular cell injury? Tubulo glomerular feed back
• Tubular obstruction by Hyaline or pigmented
  granular casts (Tamm-Horsfall proteins secreted
  by tubular epithelium)
• Back-leak of tubular fluid into the interstitial
  space (due to death of tubular cells)
• The outcome of all the above three is ?GFR
  (oliguria)
• Clinical Course Three phases
• Initial phase (first 36 hrs.), Dominated by the
  cause
• Maintenance phase Oliguria acute uremia
• Salt water retention
• Hyperkalemia and metabolic acidosis.
• Rx fluid Electrolyte balance, dialysis
• Recovery phasePolyuria electrolyte loss
• Hypokalemia (give lots of fluids K sparing
  diuretics)
• ?risk of infections
• BUN creatinine levels return to normal

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ATN- Causes
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ATN

• Necrotic Regenerating tubular epithelial cells

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• 2. Pyelonephritis (PN) Bacterial infection of
  kidney
• Causes? chronic urinary tract infection
• Routes of bacterial entry into kidneys
• 1.Ascending Infection (MCC)
• by vesico-ureteral reflux (VUR)
• 2. Hematogenous Infection (septicemia)
• Helped by lower UT obstruction
• Pathology Inflammation - renal parenchyma
  pelvis
• Clinical asymptomatic or cause severe flank pain
  fever
• Lab Bacteria, leukocytes Casts
• High risk pts DM, pregnancy UT obstruction
• Complications Necrotizing papillitis or
  papillary necrosis
• (papillary necrosis is seen in 4
  conditions????)
• ( CT scan - best investigation)
• Pathologic types Acute PN, Chronic PN

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• Acute Pyelonephritis Neutrophilic exudate
  within tubules and renal substance
• kidney is almost unrecognizable
• Complications papillary necrosis, Perinephric
  abscesses, Pyonephrosis, Scarring (Chronic
  Pyelonephritis)
• Chronic Pyelonephritis (CPN) Chronic
  tubulointerstitial inflammation
• Characterized by CRF HTN
• Pathology corticomedullary scars overlying
  dilated blunted calyces.
• Forms of CPN
• 1 Reflux nephropathy-associated type
• MCC of CPN
• MCC of reflux Congenital intra-renal reflux With
  superimposed bacterial infection (E. coli).
• 2.Obstructive type
• predisposes to recurrent bacterial infections (E.
  coli)
• Course Glomeruli undergo ischemic atrophy, total
  sclerosis with fine leathery granularity,
  shrunken.
• Finally Glomeruli disappears

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Acute Pyelonephritis

• Neutrophilic exudate within tubules and renal
  substance kidney is almost unrecognizable

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Chronic Pyelonephritis (CPN)
Thyroidization of renal tubules MOST Important
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Chronic Pyelonephritis (CPN)
obstruction
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• 3 . Acute drug-induced interstitial nephritis
• Manifests 2-40 days after the start of Rx
  (methicillin, ampicillin, rifampicin, thiazides,
  NSAID, cimetidine, .... )
• Clinical Presents with fever, skin rash,
  hematuria, proteinuria, sterile pyuria,
  Eosinophilia (allergic, parasitic and Drug
  reactions), azotemia, and acute RF
• Pathology Eosinophils and mononuclear
  infiltrates Patchy tubular necrosis
• Withdrawal of drug ? recovery
• 4. Analgesic Abuse Nephropathy Chronic
  tubulointerstitial nephritis with papillary
  necrosis
• Caused by Habitual intake of large doses
• Acetaminophen (Tylenol) ? directly damages cells
• Aspirin -vasoconstriction ? ischemia
• Pathology papillary necrosis ( other causes???)
• Clinical Presents with Polyuria, Nocturia, HTN,
  headache, GI symptoms, anemia, may develop UTI,
  may develop CRF
• Complications ? risk for TCC (Transitional cell
  Carcinoma) - renal pelvis

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Drug-induced interstitial nephritis
Numerous Eosinophils
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Analgesic Abuse Nephropathy

• Papillary necrosis

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Analgesic Abuse Nephropathy

• Can slough off and obstruct urinary tract

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• 5. Metabolic Tubulointerstitial Disease
• Urate Nephropathy form of
• Acute RF (with cancer chemotherapy).
• Chronic RF (with gout chronic lead poisoning).
• Hypercalcemia cause RF by
• Nephrolithiasis (causing UT obstruction).
• Nephrocalcinosis (causing renal atrophy).
• Multiple Myeloma
• Acute or chronic RF
• result of Bence - Jones Tamm-Horsfall
  proteinuria,
• Hypercalcemia Nephrotoxic drugs
• Cast nephropathy
• Amyloid deposits- Light-chain nephropathy -AL

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MULTIPLE MYELOMA (plasma cells)

• Note tubular casts

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Kidney
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• OBSTRUCTIVE UROPATHY (HYDRONEPHROSIS)
• Characterized by
• Unrelieved UT obstruction
• Leads to renal atrophy, with dilatation of the
  renal pelvis and calyses ? Hydronephrosis all
  widened due to obstruction and distension in
  pelvis.
• Still have glomerular filtration ? increase in
  urine load ? distension
• If Bilateral ? CRF

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HYDRONEPHROSIS

• Causes are
• Congenital anomalies
• (vesicoureteral reflux, urethral valves, meatal
  stenosis)
• Urinary calculi
• Benign prostatic hypertrophy
• Tumors
• Pregnancy
• Neurogenic bladder
• Inflammatory strictures (including
  retroperitoneal fibromatosis).

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HYDRONEPHROSIS

• Hydronephrosis all widened due to obstruction
  and distension in pelvis

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Kidney