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What is nephrotic syndrome?

Nephrotic syndrome occurs when there is a problem with the kidney’s filtering system (glomeruli) causing bloodstream proteins to leak into the urine (proteinuria). Nephrotic syndrome has many causes. The most common are focal segmental glomerulosclerosis (FSGS), minimal change disease, and membranous nephropathy.

Nephrotic Syndrome Information Sheet
Understanding Primary Nephrotic Syndrome
Understanding Primary Nephrotic Syndrome (Pediatric-focused)

What are some of the symptoms of Nephrotic Syndrome?

Large amounts of proteins lost in the urine from nephrotic syndrome may lead to:

  • Swelling in parts of the body (edema) most visible in the head, hands, feet and belly
  • Low level of protein in the blood (hypoalbuminemia)
  • High blood cholesterol (hypercholesterolemia)
  • High blood pressure (hypertension)

What causes nephrotic syndrome?

The specific cause of nephrotic syndrome can only be made with a kidney biopsy. Children, specifically, may be treated with steroids instead of having a biopsy, if there are no other complications.

Who gets nephrotic syndrome?
Anyone can get nephrotic syndrome. Nephrotic syndrome is one of the most common causes of chronic kidney disease and is responsible for about 12% of kidney failure in adults and 20% in children.

What is Focal Segmental Glomerulosclerosis (FSGS)?

Focal Segmental Glomerulosclerosis (FSGS) is a disease that affects the kidney’s filtering system (glomeruli) causing scarring and loss of large amounts of protein in the urine.

Download the brochure:  ENGLISH     SPANISH
Download the FSGS Information Sheet

Who gets FSGS?
Children and adults of all ages and races can get FSGS

What are some of the symptoms of FSGS?
FSGS causes loss of protein in the urine which may lead to:

  • Swelling in parts of the body (edema) most visible in the head, hands, feet and belly
  • Low level of protein in the blood (hypoalbuminemia)
  • High blood cholesterol (hypercholestrolemia)
  • High blood pressure (hypertension)
  • Kidney failure

What causes FSGS?
There is no single cause of FSGS. When the cause is not known it is called idiopathic or primary FSGS. In some patients FSGS may be the result of a genetic or inherited disease, an infection, or another kidney disease that leads to scarring.

What is the treatment for FSGS?
Very few treatments are available for patients with FSGS. Most often, patients are treated with drugs called steroids (prednisone or prednisolone) and with blood pressure medicines. Some patients respond well to other medicines that suppress the immune system. To date, there is no treatment that works for every person with FSGS. Patients who do not respond to treatments are at risk for kidney failure. The NEPTUNE study aims to find out more about the disease for better treatments.

How is FSGS diagnosed?
With information obtained from blood tests, urine tests, and a kidney biopsy, a physician can determine if a person has FSGS.

What is Minimal Change Disease (MCD)?

Minimal change disease can occur at any age but is the most common cause of nephrotic syndrome in children. Minimal change disease is the diagnosis given when a patient has nephrotic syndrome and a kidney biopsy shows little or no change to the structure of the kidney filters (glomeruli) or the rest of the kidney tissue. Tiny drops of a fatty substance called a lipid may be present, but no scarring has taken place within the kidney.

Download the brochure:  ENGLISH     SPANISH
Download the MCD Information Sheet

Who gets Minimal Change Disease?
People of all ages can get minimal change disease, though it mostly affects young children in the pre-school age group.

What are some of the symptoms of Minimal Change Disease?
The most common symptoms are swelling around the eyes, face, belly, and legs. A person with minimal change disease may make less urine, gain weight, and become swollen during active phases of the disease.

How is Minimal Change Disease diagnosed?
With results from blood and urine tests, and sometimes a kidney biopsy, a doctor can determine if a person has minimal change disease.

What causes Minimal Change Disease?
The cause is not known but researchers are actively trying to learn more.

What is the treatment for Minimal Change Disease?
Usually the doctor will prescribe a drug called prednisone or prednisolone. This drug helps to stop the loss of protein in the urine and increase the amount of urine expelled from the body. Most patients will improve on this drug after several weeks of treatment.

What is Membranous Nephropathy (MN)?

Membranous nephropathy is a kidney disease that is caused by a build up of proteins in the part of the kidney filter called the glomerular basement membrane. This part of the glomerulus is the thin tissue that helps separate the blood from the urine. In membranous nephropathy, the basement membrane becomes thick and damaged, allowing large amounts of protein to leak out of the blood and into the urine.

Download the brochure:  ENGLISH     SPANISH
Download the MN Information Sheet

Who gets Membranous Nephropathy?
Anyone can have membranous nephropathy, but it is more common in adults over the age of 40.

What are some of the symptoms of Membranous Nephropathy?
Symptoms occur slowly and can include swelling, weight gain, and high blood pressure.

What causes Membranous Nephropathy?
The cause is not known but researchers are actively trying to learn more.

What is the treatment for Membranous Nephropathy?
For people with large amounts of protein in the urine, medications to suppress the immune system are often used. These include corticosteroids, cyclosporine, tacrolimus, and cyclophosphamide. Limiting salt in the diet and using medications to help the body get rid of extra salt and water are often helpful. Blood pressure medications that can decrease protein in the urine are also used. Sometimes medicines are prescribed to decrease the chance of blood clots, which can be a problem in patients with nephrotic syndrome and membranous nephropathy. The NEPTUNE study aims to understand membranous nephropathy to develop better treatments.

How is Membranous Nephropathy diagnosed?
With results from blood tests, urine tests and, most importantly, a kidney biopsy, a doctor can determine if a person has membranous nephropathy.

Why is it important to collect a 24 hour urine?

This test is the best way to measure urine protein.

Download the 24 Hour Urine Information Sheet 
Download the Timed Urine Information Sheet

How do I properly collect a 24 hour urine sample?
The NEPTUNE study (or your medical center) provides specific instructions for participants. In general, 24 hour urine collection is started in the morning.

  • Do NOT save the first urine of the day, but mark this as your START time.
  • Save all urine for the next 24 hours in the provided bottle.
  • The last urine sample should be as close to the start time as possible and MUST be saved.
  • Keep the bottle in the refrigerator or on ice until your research appointment.

What if I need to collect a urine sample while away from home?
If you need to leave your house for several hours, take a backpack with clean wide mouth containers (such as a sports drink bottle) and a large plastic zip-top bag of ice. After collecting your sample in the container, store it on ice in the zip-top bag. Upon returning home, transfer your stored samples to the provided urine storage container.

What happens if I miss collecting a urine void?
For the 24 hour urine test to be accurate, all urine voids must be collected. Let your study team member know if you missed one or more samples.

How do I transfer my urine sample to the research visit?
Be sure the lid of your urine collection container is on tight to avoid leaks. If it is warm out, please use ice or a cooler to preserve the sample during transportation.

How far in advance can I collect my 24 hour urine sample?
The urine sample can be collected up to 4 days before your scheduled research appointment, as long as it is preserved on ice.

What is personalized or precision medicine?

The last decade has seen great progress in science technology. The goal of personalized medicine (sometimes called precision medicine) is to use new scientific tools to understand disease based on individual differences in genetics, biology, and environment.

Download the Personalized Medicine & Biomarkers Information Sheet

What is the goal of personalized medicine?
The goal is to move away from “one size fits all” treatments and to personalized care. Researchers want to bring new technologies to clinical care so that doctors can deliver the most effective and safest treatment to the individual.

What is a biomarker?
A biomarker is a measurement that provides specific information about a person’s health. A biomarker can be in the form of a blood or urine test, a gene or even a molecule in tissue. Biomarkers are the key to delivering personalized medicine.

How will biomarkers help people with kidney disease?
Biomarkers will be used to make a diagnosis, give individual and personalized information about prognosis, and to monitor treatment responses. As scientists discover new biomarkers, they also can provide new treatments to test in kidney disease.

How will NEPTUNE use my samples and information to find biomarkers?
NEPTUNE engages scientists from around the world to study the research samples provided by participants. To identify biomarkers of kidney disease, researchers use modern scientific tools (for example, genetics) and track an individual patient’s health in large databases. Researchers make all efforts to keep the information confidential. Your contributions will help change the future treatment of kidney disease.



Abnormal: Differing from normal.


Biopsy (BY-op-see): A procedure in which a tiny piece of a body part, such as the kidney, is removed for examination under a microscope.


Creatinine (kree-AT-ih-nin): A waste product that is removed from blood by the kidneys. If kidney disease worsens, the level of creatinine in the blood increases.

Creatinine clearance: A test that measures how efficiently the kidneys remove creatinine from the blood. Low creatinine clearance indicates impaired kidney function.


Glomerulus (gloh-MEHR-yoo-lus): (Plural: glomeruli) A tiny set of looping blood vessels in the kidney where blood is filtered.


Immune (im-MYOON) system: The body’s system for protecting itself from viruses and bacteria or any “foreign” substances.


Kidney: Bean-shaped organ that filters wastes from the blood. The body has two kidneys located near the middle of the back. They create urine, which is delivered to the bladder through tubes called ureters.

Kidney Failure: Loss of kidney function.


Nephrologist (nef-RAHL-oh-jist): A doctor who treats patients with kidney problems or hypertension.

Nephron (NEF-rahn): A tiny part of the kidneys. Each kidney is made up of about 1 million nephrons, which are the working units of the kidneys, removing wastes and extra fluids from the blood.

Nephrotic (nef-RAH-tik) syndrome: A collection of symptoms that indicate kidney damage. Symptoms include high levels of protein in the urine, lack of protein in the blood, and high blood cholesterol.


Proteinuria (PRO-tee-NOOR-ee-uh): A condition in which the urine contains large amounts of protein, a sign that the kidneys are not functioning properly.


Renal (REE-nul): Of the kidneys. A renal disease is a disease of the kidneys. Renal failure means the kidneys have stopped working properly.


Urea (yoo-REE-uh): A waste product found in the blood. Urea is normally removed from the blood by the kidneysand then excreted in the urine. Urea accumulates in the body of people with kidney failure.

Uremia (yoo-REE-mee-uh): The illness associated with the buildup of urea in the blood because the kidneys are not working effectively. Symptoms include nausea, vomiting, loss of appetite, weakness, and mental confusion.

Urinalysis (yoor-in-AL-ih-sis): A test of a urine sample that can reveal many problems of the urinary system and other body systems. The sample may be observed for color, cloudiness, and concentration; signs of drug use; chemical composition, including sugar; the presence of protein, blood cells, or germs; or other signs of disease.


Any administrative concerns can be addressed to:


Tina Mainieri

NEPTUNE Project Manager


Division of Nephrology

University of Michigan
1150 W Medical Center Drive
Ann Arbor, Michigan 48109-5657


Phone: (734) 615-5020


Looking for specific contact information for one of our participating centers?

Please visit our Participating Clinical Centers

This consortium is part of RDCRN, an initiative of ORDRNCATS