Diabetic Nephropathy

on 11.12.08 with 0 comments

  1. Know the glomerular lesions in DM. Which one is the most characteristic of diabetic nephropathy?

    Nodular intercapillary glomerulosclerosis
    • Most characteristic, but not diagnostic (amyloidosis)

    • Acellular

    • Located in mesangial/intercapillary regions of glomerular tufts

    • Laminated appearance and are eosinophilic on H&E stain

    • PAS+ and argyrophillic

    • Almost always seen with diffuse intercapillary glomerulosclerosis

  • Diffuse intercapillary glomerulosclerosis

    • Expansion of mesangial matrix

    • PAS+ and argyrophillic

    • Diffuse and global

    • Wrinkling and thickening of BM can be seen

  • Capsular drop lesion

    • Homogenous, waxy eosinophillic mass

    • Appears to be located between BM and overlying parietal epithelium, but lesion is IN Bowman’s capsule

  • Fibrin cap lesion

    • Not pathognomonic (FSG, reflux nephropathy, GN, artiosclerosis)

    • Eosinophillic, waxy structure located w/in lumen of one or more capillary loops

    • Red on Trichrome stain

  1. Know the characteristic vascular lesion in diabetic nephropathy

    • Subintimal hyaline change affecting both afferent and efferent arterioles

  2. Know the clinical presentation of diabetic nephropathy

    • Preclinical - microalbuminuria

    • Proteinuria (Nephrotic range in 10-15%)

    • Hematuria

    • Uremia

  3. Know the definition of microalbuminuria

    • Abnormal, but subclinical albuminuria

    • 20 mcg/min, but < 200 mcg/min

  4. Know the mechanism of thickening of the glomerular basement membrane and alteration of glomerular filtration barrier

    • Increased collagen IV

    • Increased laminin

    • Decreased proteoglycans ® less negative charged ® increased permeability to cations

    • Increased glomerular capillary pressure also increases permeability

  1. Know the hemodynamic change in diabetic nephropathy and its mechanisms

  • Larger glomeruli and attendant microvasculature could reduce vascular resistance and increase the surface area for filtration

  • Some hormonal aspects (elevated glucagons/growth hormone levels) could cause relaxation of renal vasculature

  • Enhanced renal production of prostaglandin occurs

  • ECF volume expansion is common in DM

  • Atrial peptides contribute to renal vasodilation/hyperfiltration

  • Elevated kinin

  • Increased dietary protein intake may influence

Category: Pathology Notes



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