A Deep Dive into Renal Rare Diseases for Clinical Research

The number of identified rare diseases continues to grow as new technologies allow for more detailed and specific genetic testing.

In the United States, a rare disease is defined as one that affects fewer than 200,000 people. However, because there are over 7,000 rare diseases that have been identified so far, they collectively affect nearly 30 million Americans.

For clinical researchers who specialize in renal disease, this represents an opportunity to develop treatments for some of the most under-served patient populations.

There are many reasons why rare diseases have been historically difficult to study. One is that they are, by definition, not common, which makes finding enough patients for a clinical trial a challenge. However, ongoing advances in technology have made it possible to study rare diseases in ways that were not previously possible.

As the number of identified rare diseases continues to grow, so too does the opportunity for clinical researchers to make a difference in the lives of patients with these conditions. Below, we’ll examine five common rare kidney diseases at the forefront of our clinical research.

IgA Nephropathy (Berger’s disease)

IgA nephropathy, also known as Berger’s disease or IgAN, is a type of kidney disease that involves the buildup of immunoglobulin A (IgA) in the kidneys. IgA is a protein that helps the body fight infection. In people with IgA nephropathy, the IgA buildup causes inflammation and can eventually lead to kidney failure.

IgAN is estimated to affect around 60,000 people in the United States. As such, it is the most common type of primary glomerulonephritis, a group of kidney diseases that affect the glomeruli. The glomeruli are the tiny filters in the kidney that remove waste from the blood.

IgA nephropathy typically affects people between the ages of 30 and 50 and is about twice as common in men than in women. Symptoms of IgAN can include fatigue, swelling, high blood pressure, and tea-colored urine.

While there currently is no cure for IgA nephropathy, treatment focuses on slowing the progression of the disease and managing its symptoms.

Focal Segmental Glomerulosclerosis (FSGS)

Focal Segmental Glomerulosclerosis (FSGS) is a type of kidney disease that involves scarring of the glomeruli. In FSGS, the scarring occurs in patches, or “foci,” and tends to affect only a portion of the glomeruli.

FSGS is estimated to affect around 40,000 people in the United States. It can occur at any age but is most common in people over 45 years old. Men and African Americans are also at higher risk.

Symptoms of FSGS can include fatigue, swelling, high cholesterol, and lower-than-average amounts of albumin (a protein found in the blood).

There are two common types of FSGS: secondary and primary.

• Secondary FSGS is caused by another underlying condition, such as diabetes, viral infections, or lupus.
• Primary FSGS, in contrast, refers to cases where the disease arises with no clear underlying cause.

Current treatment is based on the patient’s FSGS type and the underlying cause. This can commonly include medications to control blood pressure and cholesterol, steroids to reduce inflammation, and immunosuppressive drugs to suppress the immune system. In some cases, a kidney transplant may be necessary.

Lupus Nephritis

Lupus nephritis is a type of kidney disease that occurs when lupus, an autoimmune disease, attacks the kidneys. Lupus is a chronic condition that can cause inflammation in various parts of the body, including the joints, skin, kidneys, and brain.

In people with lupus nephritis, the inflammation damages the kidney’s filtering system, which can eventually lead to kidney failure.

Lupus nephritis is considered a rare disease, though it is estimated to affect more than 500,000 people in the United States. Although 90% of people with lupus are female, men with lupus are at a greater risk for lupus nephritis.

Symptoms of lupus nephritis can include weight gain, blood in the urine, and foamy urine.

There is no cure for lupus nephritis, but treatment focuses on managing the symptoms and slowing the progression of the disease.

Polycystic kidney disease (PKD)

Polycystic kidney disease (PKD) is a type of kidney disease that is characterized by the growth of cysts in the kidneys.

PKD is among the most common rare diseases affecting the kidneys, estimated to impact around 500,000 people in the United States. It can occur at any age, and it affects people of all races and genders.

PKD is caused by a genetic mutation, and it is believed to be passed down through families. The disease can also occur spontaneously.

Symptoms of PKD can include pain in the side, blood in the urine, high blood pressure and kidney stones. In some cases, the cysts can become so large that they cause the kidneys to fail.

Treatment for PKD currently focuses on managing the symptoms and slowing the progression of the disease. If caught early, PKD can be managed with medication and lifestyle changes. In more severe cases, dialysis or a kidney transplant may be necessary.

Fabry Disease

Fabry disease is an inherited disorder that results in the buildup of a fatty substance called globotriaosylceramide (GL3) in the body’s cells.

Fabry disease is caused by a mutation in the GLA gene, which is responsible for encoding an enzyme needed to break down GL3. Hospitals typically screen for Fabry disease when a child is born, as it can be fatal if left untreated. It is estimated to impact around 325,000 people in the United States.

Symptoms of Fabry disease can include pain in the hands and feet, fatigue, extreme pain during physical activity, and flu-like symptoms.

Currently, the only specific treatment for Fabry disease is enzyme replacement therapy, which replaces the missing enzyme needed to break down GL3. In some cases, an organ transplant may also be necessary.

Conclusion

The five diseases we covered above are just a sample of some rare diseases that have patient pools to support clinical research.

At DaVita Clinical Research, we are committed to helping find new and innovative treatments for rare diseases like those mentioned above. Contact us today to learn more about DaVita® Clinical Trials and our ongoing studies.