Module 4: Renal: Nephritic Disorders Flashcards
This card deck will cover Nephritic Disorders. First which nephritic disorders have normal complement levels?
IgA nephropathy Henoch-Schonlein Purpura Alport's Snydrome SLE (class I, II, V) Benign Hematuria
Which nephritic disorders have low complement levels?
Post-streptococcal glomerulonephritis
Membranoproliferative glomerulonephritis
SLE (class III and IV)
Bacterial endocarditis/ infected ventriculoatrial shunt
Cryoglobulinemia
The first nephritic disorder to discuss is Mesangioproliferative Glomerulonephritis (IgA nephropathy/ Berger’s Disease). What are some features?
Most common cause of nephritic syndrome in adults
- -1 to 3 days following a resp or GI tract infection (making IgA)
- -associated with liver cirrhosis, Celiac’s Disease, HIV and minimal change disease
- -most common in Asian and Caucasians in 2nd and 3rd decades
IgA nephropathy also presents in children. What syndrome is it apart of? What are features?
Henoch-Schonlein Purpura Nephritis features of HSP: --kidneys: IgA nephropathy --skin: non blanching purpuric rash ---GI: mesenteric vasculitis: red infarct (Abd pain and bloody diarrhea) --Joints: arthralgia
What is the presentation for IgA nephropathy for both adults and children?
Episodic gross hematuria Persistent microscopic hematuria (even though you dont see it the blood is there) Oliguria Periorbital Edema HTN
What is seen in the blood and urine for patients with IgA nephropathy?
Urine: protein less than 3.5 and RBC clasts
Blood: Elevated IgA, Azotemia, and Normal complement
What is seen on renal biopsy for IgA nephropathy?
LM: Diffuse proliferation of mesangial cells and deposits of mesangial matrix (thats why its pink in the pic)
–mesangial expansion and segmental hypercellularity
IF: Course granular deposits
–lumpy bumpy
–IgA and C3
–Mesangium and Subendothelium
EM: IgA and C3 deposits in the mesangium and subendothelium layer.
What are the complications seen with IgA nephropathy?
Usually self limiting in kids not adults
Iron Defiency Anemia: CHF
Switch to FSGS
–Nephritic to nephrotic
–look for frothy urine and periorbital to generalized edema
RPGN “Crescentic glomerulonephritis”
-type II
–2-3 weeks: oliguria to anuria; pericarditis, encephalopathy and ARDS
What is the pathogenesis for IgA nephropathy?
Mucosal Infections —Excess IgA — goes to the mesangial cells deposits there — expansion of the mesangium – hematuria which worsens during the period of infections
The next nephritic disorder is Post-Streptococcal Glomerulonephritis. What are the general features
Overall best outcome ( complete, spontaneous resolution)
–type III HSR to alpha 3 subunits of Type IV collagen in BM
What is the presentation for Post-Streptococcal Glomerulonephritis?
10 days after pharyngitis or 3 weeks after impetigo by Group A Beta-Hemolytic Streptococcus (S. pyogenes) b/c you need time to form immune complexes
- -more common in children 6-10 years old
- -dark, coke colored urine (Hematuria), periorbital edema and oliguria and HTN
What is seen in the urine and blood in patients with Post-Streptoococcal Glomerulonephritis?
Protein: less than 3.5g/day
RBCs: RBC casts
Blood: Low complement (hypocomplement), azotemia, elevated ASO titers/anti DNAase B titers
What is the pathogenesis for Post-Streptococcal Glomerulonephritis?
Initially: subendothelial IC deposits — rapidly cleared — resolution of hematuria
Later: Subepithelial humps — account for slow rate of resolution of proteinuria
What is seen on LM, IF and EM in post Streptococcal Glomerulonephritis?
LM: Diffuse global hypercellularity with NO thickening of GBM (Excellent prognosis)
IF: coarse granular (lumpy bumpy, IgG and C3, everywhere)
EM: Subepithelial deposits only ones that do not get cleared
–subepithelial hump of IgG and C3
What are the complications of Post Streptococcal Glomerulonephritis?
Spontaneous resolution most common outcome (Even without treatment)
RPGN: type II in 2-3 weeks
–patient goes from oliguria to anuria
–azotemia to uremia
Uremia: encephalopathy, gastritis, ARDS (ground glass appearance), uremic bleeding
The next nephritic syndrome is Membranoproliferative Glomerulonephritis. What are some features?
Thickening of BM, mesangial Proliferation and infiltration of inflammatory cells
There are two types of Membranoproliferative Glomerulonephritis. What are the features of type I ?
Type I: Most common Classical Complement Activation --idiopathic: rare Secondary forms are more common: hep C (give you cryoglobins so more likely to cause hemolysis in colder area of the body) , hep B and SLE Subendothelial deposits on EM --IgG and C3
What are features of type II Membranoproliferative Glomerulonephritis?
Type II: Dense deposit disease --Alternate complement pathway --Common in children Idiopathic: worse prognosis b.c nothing to treat --Intramembranous deposits on EM C3 only
What is the presentation for Membranoproliferative?
Nephritic or Nephrotic; presents in 1 of 4 ways
- -Hematuria or proteinuria
- –Acute nephritic syndrome with hematuria, HTN and edema
- -Recurrent episodes of gross hematuria
- -Insidious onset of edema and nephrotic syndrome
What are the complement levels for each type in Membranoproliferative?
Type I: low C1 and C4 in blood --slighly low C3 Type II: normal C1 and C4 --C3 is extremely low --C3 nephritic factor which stabilizes the C3 convertase so a continous activation of the alternate C3 pathway hence why C3 is extremely low.
What is the LM, IF and EM for membranoproliferative glomerulonephritis?
LM: both types
–diffuse global thickening of BM and hypercellularity
–silver stain: double contour (Splitting of the BM via the Mesangial cells) = tram track
EM:
Type I: subendothelial deposits of IgG and C3
Type 2: Intramembranous deposits of C3
–ribbon like deposits
Next topic is not really a syndrome more like a complication. Called Rapidly Progressive Glomerulonephritis / Crescentic Glomerulonephritis. What is the pathogenesis of this?
Proliferation of parietal epithelial cells and infiltration of macrophages and fibrin – severe glomerular BM injury
What is RPGN?
Is a group of disorders associated with a rapid decline in renal function with associated severe oliguria and if untreated death from renal failure within weeks to months. Classified into 3 types
What is the first type of RPGN?
Type I: Anti-Glomerular BM Antibody-Mediated Crescentic Glomerulonephritis.
- -type II HSR
- -characterized by linear deposits of IgG and C3 in the GBM
- -patients are said to have Goodpasture syndrome or anti-GBM disease
