Focal segmental glomerulosclerosis is a cause of nephrotic syndrome in children and adolescents,
as well as an important cause of kidney failure in adults. It is also known as "focal glomerular
sclerosis" or "focal nodular glomerulosclerosis." It accounts for about a sixth of the cases
of nephrotic syndrome. is by far the most common cause of nephrotic syndrome in children:
MCD and primary FSGS may have a similar cause.)
Appearance The individual components of the name refer
to the appearance of the kidney tissue on biopsy: focal—only some of the glomeruli
are involved, segmental—only part of each glomerulus is involved, glomerulosclerosis—refers
to scarring of the glomerulus). The glomerulosclerosis is usually indicated by heavy PAS staining
and findings of IgM and C3 in sclerotic segment. Classification
Depending on the cause it is broadly classified as:
Primary, when no underlying cause is found; usually presents as nephrotic syndrome
Secondary, when an underlying cause is identified; usually presents with kidney failure and proteinuria.
This is actually a heterogeneous group including numerous causes such as
Infections such as HIV Toxins and drugs such as heroin and pamidronate
Familial forms Secondary to nephron loss and hyperfiltration,
such as with chronic pyelonephritis and reflux, morbid obesity, diabetes mellitus
There are many other classification schemes also.
Pathologic variants
Five mutually exclusive variants of focal segmental glomerulosclerosis may be distinguished
by the pathologic findings seen on renal biopsy: Collapsing variant
Glomerular tip lesion variant Cellular variant
Perihilar variant Not otherwise specified variant.
Recognition of these variants may have prognostic value in individuals with primary focal segmental
glomerulosclerosis. The collapsing variant is associated with higher rate of progression
to end-stage renal disease, whereas glomerular tip lesion variant has low rate of progression
to end-stage renal disease in most patients. Cellular variant shows similar clinical presentation
to collapsing and glomerular tip variant but has intermediate outcomes between these two
variants. However, because collapsing and glomerular tip variant show overlapping pathologic
features with cellular variant, this intermediate difference in clinical outcomes may reflect
sampling bias in cases of cellular focal segmental glomerulosclerosis. The prognostic significance
of perihilar and NOS variants has not yet been determined. The NOS variant is the most
common subtype. Causes
Some general secondary causes are listed below: Glomerular hypertrophy/hyperfiltration
Unilateral renal agenesis Massive obesity
Scarring due to previous injury Focal proliferative glomerulonephritis
Vasculitis Lupus
Toxins Human immunodeficiency virus-associated nephropathy
Heroin nephropathy There are currently several known genetic
causes of the hereditary forms of FSGS. Some researchers found SuPAR as a cause of
FSGS. Diagnosis
Symptoms and signs In children and some adults, FSGS presents
as a nephrotic syndrome, which is characterized by edema, hypoalbuminemia, hyperlipidemia
and hypertension. In adults it may also present as kidney failure and proteinuria, without
a full-blown nephrotic syndrome. Tests
Urinalysis Blood tests — cholesterol
Kidney biopsy Differential diagnosis
Minimal change disease, especially in children Several others
Treatment Salt restriction and diuretics, such as furosemide,
for edema Antihypertensives — if the blood pressure
is too high treat present hyperlipidemia
Aldosterone antagonist to decrease proteinuria and thus offer a degree of reno-protection
Angiotensin II receptor antagonist Corticosteroids, such as prednisone — based
on the clinical judgment of physician Cytotoxics, such as cyclophosphamide may be
used to induce remission in patients presenting with FSGS refractory to corticosteroids, or
in patients who do not tolerate steroids. Plasmapheresis — blood cleansing using a
machine to remove the patient's blood plasma and replacing it with donor plasma.
Vitamin E Fish oil
Immunosuppressive drugs None — sometimes none of the above works
and the patient will require dialysis with possibly later transplantation of a new kidney.
Notable patients Former NBA basketball players Sean Elliott
and Alonzo Mourning have both survived bouts with FSGS. Mourning is an Ambassador to The
NephCure Foundation. Pro bodybuilder Flex Wheeler was diagnosed with FSGS and had a
kidney transplant. Former MLS player Clyde Simms retired from professional soccer in
2014 due to FSGS. Gary Coleman American actor, known for his
childhood role as Arnold Jackson in the American sitcom Diff'rent Strokes.
See also Glomerulonephritis
References
External links Wei C, El Hindi S, Li J, Fornoni A, Goes N,
Sageshima J, Maiguel D, Karumanchi SA, Yap HK, Saleem M, Zhang Q, Nikolic B, Chaudhuri
A, Daftarian P, Salido E, Torres A, Salifu M, Sarwal MM, Schaefer F, Morath C, Schwenger
V, Zeier M, Gupta V, Roth D, Rastaldi MP, Burke G, Ruiz P, Reiser J. "Circulating urokinase
receptor as a cause of focal segmental glomerulosclerosis". Nat Med 17: 952–960. doi:10.1038/nm.2411.
PMID 21804539. NephCure Foundation Only organization solely
committed to support research seeking the cause of Nephrotic Syndrome and FSGS, improve
treatment and find the cure. Kidcomm An online resource for parents dealing
with childhood kidney diseases FSGS Research A team of kidney doctors and
scientists from Brigham and Women's Hospital / Harvard Medical School working to learn
more about the cause of FSGS and Nephrotic Syndrome in children and adults, with an emphasis
on the genetic basis of these diseases. A general overview of Renal Pathology
Tahzib M, Frank R, Gauthier B, Valderrama E, Trachtman H. "Vitamin E treatment of focal
segmental glomerulosclerosis: results of an open-label study". Pediatr. Nephrol. 13: 649–52.
doi:10.1007/s004670050674. PMID 10502120.