Nephrotic-FSGS Flashcards
What is FSGS?
A disease characterized by the deposition of basement membrane like material associated with podocyte injury, not all Glomeruli are affected (Focal) and involving only segments of each affected glomerulus (segemtal), but progressing to sclerosis.
In what population sub-set is FSGS most common?
Mainly in young black males.
Can FSGS be familial?
Yes!
What are some of the diseases that FSGS can be secondary to?
- Glomerulonephritis (e.g IgA nephropathy)
- Maladaptive response to nephron loss
- HIV
- Parvovirus B19 infection
- Injection drug use (heroin)
- Lithium
- Pamidronate
- Morbid Obesity
- Reflux Nephropathy
- Sickle cell nephropathy
What is the anatomical damage done in FSGS?
Epithelial damage; loss of foot process
What are the microscope findings in FSGS?
- Scarring
- Obliterated capillary lumen (Hyalinosis)
- Areas of adhesion to bowman’s capsule
- Expansion of mesangial matrix
Nephrotic syndrome in FSGS results in what kind of proteinuria?
Non specific protein loss (albumin AND globins)
What are the mutated proteins in familial and sporadic FSGS?
- Podocin
- Alpha-actinin-4
- TRCP6
- ApoL 1 (In African Americans)
- Neprin
What circulating factor is elevated in and may play a role in FSGS?
suPAR
How can suPAR be used for therapy?
Removal via plasmapheresis induces disease remission.
What is suPAR’s function?
Binds to and activates beta3-integrin, one of the major proteins anchoring podocytes to the underlying GBM.
What does the hyalinosis in FSGS represent?
The entrapment of plasma and lipids in foci of injury, which go on tp become sclerotic.
Where might there be immunoglobulin or complement in FSGS?
In the FOCI. (IgM and C3 focal deposits)
What is initially affected in primary FSGS?
Juxtamedullary glomeruli
What parts of nephron become subsequently affected?
Tubules atrophy with interstitial fibrosis
What is Perihilar FSGS?
Diesease localizes predominantly to the vascular pole of the glomerulus. Uncommon in children and accounts for 26% of cases. Has lowest incidence of renal insufficiency and nephrotic range proteinuria but highest incidence of hypertension.
What are the characteristics of the TIP subtype of FSGS?
- Localizes primarily at the urinary pole of the glomerulus.
- Affects predominantly white adults
- 17% of cases
- Most likely to obtain remission.
What are the characteristics of Collapsing FSGS?
- Collapse of all parts of the glomerular tuft
- Podocyte hypertrophy
- Tubular Dilation
- Predominantly among Black children
- Accounts for 11% of cases
- Have heavier proteinuria and worst renal survival
- Associated with HIV infection and Drug toxicity
- Rapid progression
- EM may reveal tubuloreticular inclusions
What are the characteristics of Cellular subtype of FSGS?
1.3% of cases
What are the signs and symptoms of FSGS?
1.Nephrotic syndrome
2.Hypertension
3.Microscopic hematuria (555 children 45% adults)
4.
How is FSGS diagnosed?
Renal Biopsy
What are the treatments for FSGS?
- Corticosteroids
2. Calcineurin inhibitors (cyclosporin or tacrolimus)
What is the prognoses in FSGS?
1.50% of patients develop end stage renal disease within 10 years of diagnosis
In patients with great similarities ofsymptoms for MCD and FSGS what charateristics lean to FSGS?
- Older age
- Hematuria
- Hypertension
- Non slective proteinuria
- Poor response to protein therapy
What is the primary cause of FSGS?
iDIOPATHIC
What role do ApoL1 mutations play in FSGS?
Mutations causing truncations of apolipoprotein L1 conferring resistance to trypanosomiasis and susceptibility to FSGS
What does SuPAR do in FSGS?
The circulating factor binds to the podocyte anchor beta3-integrin and could be a common cause of FSGS.
