2. FSGS: Epidemiology
Focal segmental glomerulosclerosis accounts for
approximately 20% of cases of the nephrotic
syndrome in children and 40% of such cases in
adults, with an estimated incidence of 7 per 1
million.
3.
4.
5.
6. Classification
Primary or idiopathic FSGS: Typically presents
with the nephrotic syndrome.
Secondary FSGS: Typically presents with non-
nephrotic proteinuria and often renal insufficiency.
Distinguishing between primary and secondary
disease is particularly important because of the
markedly different approach to therapy in the two
disorders.
11. Histologic variants
Classic FSGS, also called FSGS NOS (Not
Otherwise Specified), is the most common form.
Collapsing variant
Tip variant
Perihilar variant
Cellular variant
Foot process effacement is relatively mild in FSGS
NOS & perihilar variant.
12. Histologic Variants
To make the histologic Dx of FSGS the perihilar,
cellular, tip and collapsing variants must be excluded.
Light and Electron microscopy is necessary for
accurate Dx.
Light will show mesangial collapse and sclerosis.
Electron will show diffuse fusion of the epithelial cell
foot process.
17. FSGS collapsing variant
The most rapidly progressive form of FSGS. It does not
typically respond to therapy. Ptns. require dialysis or a kidney
transplant within one to two years despite treatment.
19. Prognosis
Untreated primary FSGS often follows a progressive course
to end-stage renal disease (ESRD).
The rate of spontaneous complete remission among patients
with nephrotic syndrome <10%.
Spontaneous remission is more likely to occur among
patients with normal kidney function and non-nephrotic
proteinuria.
20. Prognosis
Factors that appear to influence response to
treatment and/or prognosis include:
Degree of proteinuria.
Renal dysfunction.
Histologic findings.
Interstitial fibrosis.
21. Prognostic Factors
No Nephrotic Syndrome-85% 10 yr survival
Nephrotic Syndrome- 60-90% 5 yr survival
30-55% 10 yr survival
Massive Proteinuria- progress to ESRD w/in 5 yrs
Interstitial Fibrosis- poor renal survival
Collapsing Variant- worse prognosis (HIV)
Glomerular Tip Lesion- More likely to respond to
steroid therapy
22. Response to therapy
A complete response is a reduction in proteinuria to
<200 to 300 mg/day.
A partial response in patients presenting with
nephrotic range proteinuria is a reduction of ≥50
percent, and to less than 3.5 g/day.
A relapse is return of proteinuria to ≥3.5 g/day in
someone who had undergone a complete or partial
remission.
26. Plasmapheresis
There may be a limited role for plasmapheresis in the
treatment of primary FSGS, based in part upon studies
in patients who have recurrent FSGS in the renal
allograft.
Removal of a circulating factor by plasmapheresis or
a protein adsorption column can dramatically reduce
proteinuria and, in some cases, induce complete
remission.
27. Plasmapheresis
Whether a patient with primary FSGS might
respond to plasmapheresis is thought to vary with
the presence or absence, and the absolute level, of
the circulating permeability factor.
Plasmapheresis should be performed in
conjunction with immunosuppression.
28.
29. FSGS & kidney Tx summary:
Recommendations; (A) Candidates with FSGS should be warned that there
is a 20–40% risk of recurrence, and that 40–50% with recurrence lose their
grafts. However, the risk of recurrent FSGS need not preclude transplantation.
(B) A prior history of graft loss from recurrent FSGS should be considered at
least a relative contraindication to living donor transplantation, due to the
likelihood of recurrence (up to 80%).
(C) Assays for a serum factor to predict recurrent FSGS have not been
standardized or validated for clinical practice.
(D) There are not yet sufficient data for or against the use of prophylactic
plasma exchange or other measures to prevent recurrent FSGS.