(MHD) Lecture 3- Renal Path II Flashcards
What is the key characteristic associated with all RPGN subtypes, regardless of etiology? Describe what it is.
CRESCENTS
They consist of fibrin and plasma proteins (C3b) with glomerular parietal cells, monocytes and macrophages.
These are formed to slow the bleeding associated with RPGN, but ultimately go on to decrease filtration thus progressing RF.
List the (3) types of RPGNs
- Type I: Anti-glomerular basement membrane antibody (Goodpastures)
- Type II: Circulating IC glomeruionephritis
- Type III: “Pauci-immune”/ANCA associated
People with RPGN are Almost Certaintly Passing Away
RPGN Type I
Describe the typical presentation. Who has it? What is the pathogenesis/what causes it? What syndrome is associated with it?
- Gross hematuria, dec. in urinary output, and hemoptysis
- Young MEN
- Toxins (smoking, ciruses, paints/dyes) lead to the generation of anti-GBM antibodies (IgG) which deposit along the length of the GBM and necrose, causing sieve effect.
- Associated with Goodpastures Syndrome
What is Goodpastures Syndrome?
Form of Type I RPGN
Antibody cross-reactivity w/ pulmonary alveolar basement membrane. Antibodies bind to the alveolar BM, leading to hemorrhage and hemoptysis.
Testing and Treatment of RPGN Type I
- Linear stain for IgG (Immunofluoresence only)
- glomeruli/pulmonary alveoli
- Treatment: plasmapharesis (removal of pathogenic antibodies from circulation)
RPGN Type II
How common is it? Who is affected by it? Describe the pathology of it. What is the procedure that must be done in the process of testing for it?
- Uncommon (1% of IgA, Postinfectious and SLE lead to this form of RPGN)
- Children/ Young Adults (10-40 y/o)
- Crescents and Immune complexes from (IgG/C3; IgA/C3)
- Kidney biopsy rewuired due to nonspecificity
RPGN Type III
Describe the typical presentation. Who has it? What is the pathogenesis/what causes it?
- Presentation: drop in urinary output, gross hematuria, hemoptysis/SOB, prior history of sinusitis or ear/nose/throat issue (Ear/nose/throat, Lung, and Kidney = ELK)
- Older patients
- Caused by ANCA which leads to pauci-immune crescents
What key characteristics (3) are absent in the pathology of RPGN type III
- No immune complex deposits
- No electron dense deposits
- No anti-glomerular basement membrane autoantibodies
What is ANCA?
AntiNeutrophil Cytoplasmic Autoantibodies
React with neutrophil antigens to cause premature degranulation/activation and release of lytic enzymes, causing cresentic glomerulonephritis/ systemic vasculitis.
Associated with RPGN type III
Wegener Granulomatosis vs Churg-Strauss Syndrome
Both are forms of Type III RPGN
- Wegener: Has “c-ANCA” which binds PR3 antigen of neutrophil; Microscopic Angiitis
- Churg-Strauss: Has “p-ANCA” which binds MAO; also associated with allergies, allergic rhinitis and eosinophilia!__!! Also have necrotizing granulomas.
What is the most obvious clinical manifestation of Nephrotic Syndrome?
Generalized Edema due to the loss of protein
Membranous Nephropathy
Typical clinical presentation? Who gets it? Describe the etiology/pathology?
- Edema, thrombosis (loss of AT3), Infections (loss of Globin for Ig)
- 30-60 y/o
- Wide variety of etiologies (85% autoimmune) –> in-situ subepithelial IC formation
- ICs react to the basal surface of podocytes causing loss of slit diaphragms, foot process effacement and severe proteinuria.
What pattern does membranous nephropathy take on silver stain?
Spike and dome pattern
ICs = silver negative
BM = silver positive (black)
Membranous Nephropathy Prognosis and Treatment
Prognosis: 1/3 have spontaneous remission; 1/3 progress to require dialysis; 1/3 continue to have proteinuria w/o progression to renal failure
Treatment: difficult; immunosuppresive drugs (predinisone); treatment of underlying disease (secondary)
