L9- Nephritic Syndrome Flashcards
describe urine sediment in nephritic syndrome
- RBCs / RBC casts
- granular casts
- variable proteinuria
- possible WBCs
list the Nephritic syndromes based on complement levels
Normal: i) IgA nephropathy (Henoch-Schonlein Purpura), ii) Alport’s Syndrome (hereditary nephritis), iii) SLE (class I, II, V), iv) benign hematuria
Low: i) post-streptococcal glomerulnephritis, ii) membranoproliferative glomerulonephritis, iii) SLE (class III, IV), iv) bacterial endocarditis / infected ventriculoatrial shunt, v) cryoglobulinemia
Variable: rapidly progressive glomerulonephritis
the most common glomerulonephritis is (1) and is mostly seen in (2) age group and (3) ethnicities
1- IgA nephropathy
2- children, young adults
3- asians, whites
In IgA nephropathy, exposure to microbes or other Ags in the (1) leads to increased IgA synthesis. This allows for IC deposition in (2) where they will activate (3) and initiate (4).
1- GI, lungs
2- mesangium (+ its proliferation)
3- alternative complement pathway
4- glomerular injury
describe microscopic appearance of IgA nephropathy
LM- segmental areas with inc mesangial matrix + hypercellularity
IF- mesangial and subendothelial IgA, C3 deposits (C1q, IgG/IgM either absent or in very low levels)
EM- mesangial and subendothelial deposits
People with IgA nephropathy will present with episodes of (1) with (2) in between episodes and (3) is evident along with normal levels of (4).
(T/F) most people will progress to ESRD
(T/F) most cases are restricted to the kidney
1- gross hematuria 2- microscopic hematuria 3- proteinuria (<3.5g/day) 4- C3/C4 5- F, 20% progress to ESRD 6- T
list the 4 conditions commonly associated with IgA nephropathy
- hepatic cirrhosis
- gluten enteropathy
- HIV infection
- minimal change disease
In post-streptococcal glomerulonephritis, initially (1) forms and will make (2) deposits in the kidney. This will activate (3) resulting in influx of (4) and eventually decline in (5). Deposits will quickly (6), along with (7) symptoms.
1- Ab-Ag immune complex with streptococcal Ag 2- subendothelial 3- complement 4- inflammatory cells 5- GFR 6- clear (therefore not seen on biopsy) 7- hematuria, renal failure
After the clearance of IC in post-streptococcal nephritis, (1) is the main characteristic feature responsible for (2). (1) will be cleared slowly and therefore (3) symptoms and lesions will take (4) amount of time to resolve.
1- subepithelial ‘humps’ / ICs
2- epithelial damage –> proteinuria
3- proteinuria
4- 2 mos to start and up to 9 mos - years for complete resolution
Note- subendothelial ICs are cleared quickly b/c no GBM between it and blood like with the subepithelial ICs
describe the appearance of post-streptococcal glomerulonephritis on microscopy
LM: hypercellular glomeruli (neutrophils, monocytes), mesangial/epithelial/endothelial proliferation, diffuse (all glomeruli in all parts), closed capillary loops (due to cell infiltration and swelling)
IF: IgG, C3 granular deposits in mesangium + along capillary walls
EM: electron dense deposits in subepithelial space (‘humps’)
GN usually appears (1) after strep. pharyngitis or (2) after impetigo. It is common in (3) age group and has a (rapid/gradual) onset. It is defined by having (5) and (6) levels.
1- 10 days (throat) 2- 3 weeks (skin) 3- children (6-10 y/o) 4- rapid nephritic syndrome 5- proteinuria >2g/day 6- low complement levels
_________ are useful blood tests in diagnosing post-streptococcal GN
-elevated anti-streptolysin O Ab
-elevated anti-DNAase B
(+ low complement)
list the possible clinical outcomes of post-streptococcal GN
-children renal function recovers 99% of the time
- Long-term: some develop renal insufficiency 10-40 yrs after, due to the following:
i) irreversible glomerular damage during acute episode
ii) compensatory hyperfiltration by remaining glomeruli (maintain normal GFR)
iii) eventually => glomerulosclerosis
MPGN, aka (1), is characterized by the following: (2). It can be primary due to (3) or secondary due to (4).
1- membranoproliferative glomerularnephritis
2- GBM thickening, mesangial proliferation, inflammatory cell infiltration
3- idiopathic
4- underlying systemic disease
(3/4 have same histological findings)
describe the appearance of MPGN on LM
- all 3 types are identical on LM
- mesangial expansion
- hypercellularity
- peripheral capillary loop thickening double contour formation – GBM duplication (its split) ‘tram track’
describe the appearance of MPGN on EM
- Type I: subendothelial deposits (C3, IgG, C1q, C4)
- Type II: intramembranous (w/in GBM) deposits (C3 - NO IgG, C1q, C4)
- Type III: subendothelial, mesangial, subepithelial deposits (C3, IgG)
The most common MPGN is type (I/II/III) and due mostly to (primary/secondary), therefore there is usually an evaluation for the following, (3).
1- type I
2- secondary (primary / idiopathic is rare)
3- SLE, HepC, cryoglobulinemia, endocarditis, parasitic infection
MPGN type I activates (1) and type II activates (2). In both C4 levels are (high/low/normal) and C3 levels are (high/low/normal) because of (5).
1- classical complement pathway (type I)
2- alternative complement pathway (type II)
3- normal (C4)
4- low (C3)
5- C3 nephritic factor = IgG that binds and stabilizes C3bBb convertase => continuous C3 degradation
MPGN presents (before/after) 30 y/o in one of the following ways: (2). (T/F) most people will progress to ESRD.
1- before 2: -hematuria/proteinuria in UA -acute nephritic syndrome w/ hematuria -HTN, edema -recurrent episodes of gross hematuria -insidious onset of edema and nephrotic syndrome 3- T, in 10-15 yrs
RPGN, aka (1) or (2), is a group of disorders associated with (3) and if untreated it will result in (4). (5) is required for diagnosis.
1- rapidly progressive glomerulonephritis 2- crescentic glomerulonephritis 3- severe oliguria 4- renal failure (wks-mos) 5- renal biopsy, serological analysis
describe the appearance of RPGN on LM
- proliferative glomerulonephritis with prominent ‘crescent’ formation in 30-70% of glomeruli (proliferation in extracapillary space / Bowman’s space)
- w/ or w/o segmental necrosis
- crescents: cellular –> fibrocellular –> fibrous
- all three types present the same
RPGN:
(1) % type I
(2) IF staining
(3) alternate name
(4) causes
Type I RPGN 1- 20% 2- linear staining 3- anti-GBM disease 4- Goodpasture's syndrome, idiopathic
RPGN:
(1) % type II
(2) IF staining
(3) alternate name
(4) causes
Type II RPGN 1- 40% 2- granular staining 3- immune complex disease 4- SLE, post-infectious, IgA, Henoch-Schonlein, idiopathic
RPGN:
(1) % type III
(2) IF staining
(3) alternate name
(4) causes
Type III RPGN 1- 40% 2- no staining 3- pauci-immune glomerulonephritis 4- (vasculitis) Wegner's, Microscopic PA, Churg-Strauss, idiopathic
