Robbins - 517-533 - Glomerulus, Nephrotic, Nephritic Flashcards
Glomerular diseases are often ___ mediated
Immunologically
___ injury may account for instances of GN in which either there are no deposits of Ab’s or immune complexes
T Cell-Mediated injury
___ mechanisms underlie most types of primary glomerular diseases
Immune
___ molecules from adjancent foot processes bind to each other thru disulfide bridges
Nephrin
2 etiologies of Dense Deposit Disease
Auto-Ab to C3 Nephritic Factor - uncontrolled cleavage of C3; Mutations or Auto-Ab’s to Factor H
2 most prevalent primary glomerular diseases in Adults
- Focal Segmental Glomerulosclerosis; 2. Membranous Nephropathy
2 Typical Features of Immune Complex Disease
(1) Hypercomplementemia; (2) Granular deposits of IgG, complement on GBM
3 damaging substances released by Neutrophils
Proteases, ROS, AA metabolites
3 most frequent systemic causes of nephrOtic syn in adults are
Diabetes, Amyloidosis, SLE
5 manifestations of Nephritic Syndrome
Hyper GrAPE: HTN, Gross Hematuria, Azotemia, Proteinuria, Edema
85% of Membranous Nephropathy is caused by
Ab’s that cross-react with podocyte antigens
AA metabolites released by Neutrophils cause
reduction in GFR
Ab-mediated GN in humans results from
Formation of auto-Ab’s directed against GBM
Ab’s against what are suspected when immune complexes are not found in GN
Against Glomerular cell antigens
Acute Postinfectious GN is caused by
Glomerular deposition of immune complexes; Results in proliferation and damage to glomerular cells and infiltration of leukocytes
After “maladaptive” changes following significant Nephron loss, what happens?
Capillary obliteration, Increased deposition of mesangial matrix and plasma proteins, and ultimately sclerosis of glomeruli –> Further reductions in nephron mass
After significant nephron loss, remaining glomeruli tend to undergo ___? This is associated with what hemodynamic changes?
Hypertrophy to maintain overall renal fxn; Increases single-nephron GFR, BF, and transcapillary pressure
Age range for IgA Nephropathy
Children and Young Adults
Age range for Minimal Change Disease
1-7 years
Age range of Membranous Nephropathy
30-60, slowly progressive
Alport Syndrome is a mutation in
Alpha chains of Type IV Collagen
Alport Syndrome is a type of
Hereditary Nephritis
Alport Syndrome is characterized by
Nephritis, Nerve Deafness, Eye disorders
Anti-GBM Ab GN is characterized by what IF pattern
Linear
Anti-GBM Ab-mediated Crescentic GN is characterized by
Linear deposits of Ig, and often C3 on GBM
Anti-GBM Crescentic: Clinical presentation
Severe glomerular damage with necrosis and crescents - Rapidly progressive GN
Antibodies directed to what glomerular region tend NOT to elicit inflammation
Subepithelial
Antigen in most cases of Membranoproliferative GN
Unknown
Antigens in Classic Crescentic GN
Fixed antigens in GBM
Auto-Ab to C3 Nephritic Factor - uncontrolled cleavage of C3; Mutations or Auto-Ab’s to Factor H
2 etiologies of Dense Deposit Disease
Azotemia, Hematuria, HTN in NephrOtic syn
Little to no Azotemia, Hematuria, HTN
Basketweave =
Hereditary Nephritis
Best-characterized Anti-GBM GN
Classical Anti-GBM Crescentic GN
Causes of MPGN vs DDD
MPGN is immune complex deposition vs DDD is Complement dysregulation
Characteristic histological findings in RPGN
Crescents
Characteristic IF picture of IgA Nephropathy
Mesangial deposition of IgA (often with C3, properdin, and small amounts of IgG or IgM)
Chronic renal disease damages what components of nephron
All 4
Classic presentation of Acute Post-Strep GN
Nephritic Syndrome
Collapse of Glomerular Tuft and Podocyte Hyperplasia
Collapsing Gnephropathy is characterized by
Collapsing Gnephropathy is a variant of
FSGS
Collapsing Gnephropathy is characterized by
Collapse of Glomerular Tuft and Podocyte Hyperplasia
Complexes deposited in what location tend to elicit inflammatory reaction
Endothelium or subendothelium
Crescents can be a complication of any
immune complex nephritides
Cut-offs for Proteinuria and Hypoalbuminea in NephrOtic syndrome
3.5g proteinuria, 3 g/dL Albumin
DDD (as opposed to Type 1 MPGN) is characterized by
Ribbon-like intramembranous deposits
Deposition of Auto-Ab’s directed against GBM show what pattern on IF
Linear pattern
Deposition of circulating immune compelxes gives what IF pattern
Granular
Diameter of Fenestra
70-100 nm
Diameter of Filtration Slits
20-30 nm
Early and Late EM changes in Hereditary nephritis
Early: Thin GBM; Late: Basketweave
Elevation of BUN and Creatinine; Usually reflects decreased GFR
Azotemia
EM findings in Post-infectious GN
Subepithelial Humps
Evidence suggests that IgA Nephropathy is an abnormality in
IgA production and clearance; Ab’s against abnormally glycated IgA
FSGS is associated with what other conditions
HIV, Heroin abuse; Secondary event in other forms of GN
Fundamental Abnormality in Dense Deposit Disease
Excessive complement activation
Glomerular lesions from immune complex disease usually consist of
Leukocyte infiltration into glomeruli; Variable proliferation of endothelial, mesangial, and parietal epithelial cells
Gross Hematuria, Proteinuira, Azotemia, Edema, HTN: Hyper GrAPE
Nephritic Syndrome
Hallmark of IgA Nephropathy
Deposition of IgA in Mesangium
Hemodynamic changes caused by Hypertrophy of remaining nephrons in end-stage kidney disease lead to
Further endothelial and podocyte injury, increased glomerular permeability to proteins, accumulation of proteins and lipids in mesangial matrix
Hereditary Nephritis is caused by
Mutations in genes encoding GBM proteins
Histologic features of glomeruli in FSGS
Increased MM, Obliterated capillary lumina, Deposition of hyaline masses and lipid droplets