12. Renal Pathology E - Cox

• Takayasu arteritis - Pulseless disease 

  • Segmental, patchy granulomatous inflammation + fibrosis
  • resulting in stenotic occlusion
• 2 stage of disease of Takayasu

  1. transmural inflammation
  2. pulseless
  3. hypertension
  4. ischemia
  5. occlusion
• Polyarteritis nodosa (PAN)

  • transmural involvement vessel fibrinoid necrosis
  • intima or media proliferation leading to vessel obstruction and tissue ischemia
  • inflammatory destruction of vessels leading to rupture
• Granulomatosis with polyangiitis (GPA)

  • crescentic and necrotizing glomerular lesion - fibrocellular crescent
  • pauci-immune
• GPA

  • hematuria
  • proteinuria
  • increase creatinine
  • HTN
• Microscopic polyangiitis (MPA)

  • necrotizing glomerulonephritis - hematuria + proteinuria
  • absence of granuloma
• Eosinophilic granulomatosis with polyangiitis (EGPA)

  • eosinophil rich granulomatous vasculitis
• Cryoglobulinemic small vessel vasculitis (CSVV)

  • cryoglobulin - IgG + IgM - immune deposit
  • precipitate + clump leading to occlusion and ischemia
• Thrombotic Microangiopathies (TMA)

  • thrombosis leading to necrosis + thickening of vessels walls
• TMA clinical

  • Hemolytic uremic syndrome (HUS) - endothelial damage due to bacterial or antibodies
• TMA - HUS linked to toxic e coli (EHEC)
• TMA - HUS symptoms

  • diarrhea
  • oliguria
  • hematuria
  • HTN
  • thrombosis
• TMA - atypical HUS - due to uncontrolled alternative complement activation
• Atypical HUS

  • no diarrhea
  • no shiga toxin
  • can relapse after complete recovery
• TMA - TTP: classic pentad

  • fever
  • ARF
  • neurological changes
  • thrombocytopenia
  • MAHA
• TMA: TTP - large uncleaved multimer result in abnormal platelet aggregation leading to thrombosis
• Benign nephrosclerosis - increase basement membrane matrix
• Malignant & accelerated nephrosclerosis - due to essential hypertension

  • sudden high BP causing endothelial injury
• Malignant + accelerated nephrosclerosis

  • kidney ischemic --> activate RAAS leading to increase HTN
• Malignant & accelerated nephrosclerosis - thickening and proliferation arterial wall smooth muscle cell

  • collagen deposition producing onion skin
• Onion skin is due to collagen deposition

  • seen with scleroderma renal crisis
  • will cause luminal narrowing
• Renal artery stenosis (RAS) - will cause renovascular hypertension

  • commonly due to atherosclerosis
• RAS will cause progressive lumen narrowing leading to decrease perfusion
• RAS will cause decrease blood flow + decrease capillary hydrostatic pressure

  • kidney thinks there is low BP - leading to secondary hypertension due to release of aldosterone + ANG II
• 2 types TMA

  • HUS - due to shiga toxin
  • TTP - MMP causing abnormal vWF cleavage