Nephritis Flashcards
What is the distinguishing feature in nephritic syndromes?
hematuria with or without mild proteinuria
In addition to hematuria, nephritic syndromes are characterized by what findings?
- dysmorphic RBCs
- red cell casts
- oliguria
- azotemia
- HTN
What is the common pathophysiologic denominator in all nephritic diseases?
proliferation of cells within the glomerulus, including leukocyte infiltration. These inflammatory cells damage the GBM allowing RBCs to escape into urine, resulting in attempts to compensate: oliguria and hypertension. The GBM damage may be enzymatic or structural (by immune complexes), and damage to other components (such as the endothelium and epithelium) will give rise to associated mild proteinuria.
Acute post streptococcal glomerulonephritis is a sub type of which disease?
diffuse proliferative glomerulonephritis
What does the word “proliferative” mean in diffuse proliferative GN?
neutrophilic infiltrate of the glom
” Classically refers to hematuria in a young child 7-30 days after an infection, a transient upper respiratory (URI) or skin infection by Group A β-hemolytic Strep. “
What are the LM findings for this condition?
PSGN
LM: neutrophils and monocytes infiltrating the glom with scattered fibrin thrombi
” Classically refers to hematuria in a young child 7-30 days after an infection, a transient upper respiratory (URI) or skin infection by Group A β-hemolytic Strep. “
What are the FM findings for this condition?
PSGN
FM: granular IgG and C’ deposits,
” Classically refers to hematuria in a young child 7-30 days after an infection, a transient upper respiratory (URI) or skin infection by Group A β-hemolytic Strep. “
What are the EM findings for this condition?
PSGN
dense subepithelial humps
What kind of immune complexes are deposited in PSGN?
IgG and C’ on the GBM
What is RPGN?
RPGN is a clinical syndrome of rapid loss of renal function,
Describe crescentic GN. What is this a histologic sign for?
crescents in most gloms: proliferation of parietal epithelial cells of Bowman’s capsule, needs to involve >50% of gloms (since may have occasional crescents in other types of kidney injury).
RPGN sign
Do RPGN patients require dialysis?
Yes, within weeks or months
What findings divide crescentic GN into 3 types?
FM and EM findings
How many types of crescentic GN are there?
3
- anti GBM
- IC
- pauci-immune
This disease has linear IgG deposits +/- C3 along with crescentic GN on FM and EM.
Type I anti GBM RPGN
How is type I anti GBM RPGN treated?
plasmapharesis to remove anti GBM antibodies
granular IC deposits with ‘lumpy-bumpy’ appearance on EM with crescentic GN.
This is a sign of what disease?
type II IC RPGN
How does type II IC RPGN occur?
as complication of any of the autoimmune disorders with immune complex formation (such as SLE, post-streptococcal GN, or Henoch-Schonlein purpura)
Crescentic GN without anti-GBM antibodies, and FM/EM negative, as well as +ANCAs is what disease?
type III pauci immune RPGN
What causes type III pauci immune RPGN
complication of vasculitis (polyarteritis nodosa or granulomatosis with polyangiitis or eosinophils).
What are the 3 main types of ANCA?
MPO (p ANCA)
PR 3 (c ANCA)
atypical (x ANCA)
What histological type of crescentic GN/RPGN is associated with + ANCA?
type III pauci immune
What are the 2 classic vasculitides assocaited with crescentic GN and therefore, RPGN?
MPA: Microscopic polyangiitis = vasculitis with neutrophils (usually p-ANCA)
GPA: Granulomatosis with Polyangiitis = formerly Wegener’s granulomatosis – vasculitis with neutrophils and granulomas (usually c-ANCA)
What is microscopic polyangitis?
vasculitis with neutrophils (p ANCA) that can cause type III crescentic GN and RpGN
