Focal segmental glomerulosclerosis

Synonyms

FSGS
Primary FSGS
Secondary FSGS
Chronic Kidney Disease
Nephrotic Syndrome

Overview

Focal segmental glomerulosclerosis (FSGS) is a cause of nephrotic syndrome in children and adolescents, as well as a leading 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. (Minimal change disease (MCD) is by far the most common cause of nephrotic syndrome in children: MCD and primary FSGS may have a similar cause.)

Symptoms

In children and some adults, FSGS presents as a nephrotic syndrome, which is characterized by edema (associated with weight gain), hypoalbuminemia (low serum albumin, a protein in the blood), hyperlipidemia and hypertension (high blood pressure). In adults it may also present as kidney failure and proteinuria, without a full-blown nephrotic syndrome.

Causes

Some general secondary causes are listed below:

  • Glomerular hypertrophy/hyperfiltration
    • Unilateral renal agenesis
    • Morbid obesity
  • Scarring due to previous injury
    • Focal proliferative glomerulonephritis
    • Vasculitis
    • Lupus
  • Toxins (pamidronate)
  • Human immunodeficiency virus-associated nephropathy
  • Heroin nephropathy

Focal segmental glomerulosclerosis may develop following acquired loss of nephron's from reflux nephropathy. Proteinuria is nonselective in most cases and may be in subnephrotic range(nephritic range <3.0gm/24hr) or nephritic range.

There are currently several known genetic causes of the hereditary forms of FSGS.

Diagnosis

Tests

  • Urinalysis
  • Blood tests — cholesterol
  • Kidney biopsy

Treatment

  • Salt restriction and diuretics, such as furosemide, for edema
  • Antihypertensives (especially ACEIs) — if the blood pressure is too high but not so for it, it has another protective effect
  • Treat present hyperlipidemia (e.g. statins, fibrates; although fibrates are contraindicated in renal failure)
  • Aldosterone antagonist to decrease proteinuria and thus offer a degree of reno-protection
  • Angiotensin II receptor antagonist
  • Rituximab
  • Galactose
  • Pirfenidone
  • Tacrolimus
  • Abatacept
  • Corticosteroids, such as prednisone — based on the clinical judgment of physician (no broad consensus/guideline)
  • 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
  • If none of the above works, the patient will require dialysis with possibly later transplantation of a new kidney that probably will be lost fast by FSGS due the FSGS agressor agent on the blood.

Resources

  • American Kidney Fund: http://www.kidneyfund.org/
  • National Kidney Foundation: https://www.kidney.org/
  • Nephrotic Syndrome Study Network: http://www.neptune-study.org/
  • NephCure Kidney International: https://nephcure.org/
  • https://nephcure.org/livingwithkidneydisease/nephcure-community-education/