Focal Segmental Glomerulosclerosis - An Overview

Introduction

The human body has two kidneys. The kidneys are shaped like beans and are present on either side of the spinal cord below the rib cage on the backside. It performs several functions, including filtering the blood to remove excess fluid and waste from the body. Focal segmental glomerulosclerosis is a specific type of kidney damage.

What Is Focal Segmental Glomerulosclerosis?

Focal segmental glomerulosclerosis is a condition that occurs when the tiny filters in the kidney called glomeruli become sclerosed or hardened. Each kidney has around a million glomeruli, which are part of the basic unit of the kidneys known as the nephron. The glomeruli help in filtering excess water and waste out of the body. Due to the scarring or hardening of these tiny filters, the kidneys cannot remove the waste products from the body via urine. Eventually, these abnormalities may lead to progressive kidney damage, including decreased kidney function causing kidney failure. Focal means only some filters are damaged, and segmental means only some parts of the filters are hardened.

What Are the Different Types of Focal Segmental Glomerulosclerosis?

The various types of focal segmental glomerulosclerosis include:

• Primary Focal Segmental Glomerulosclerosis: Primary focal segmental glomerulosclerosis includes people with no known cause of their condition (idiopathic focal segmental glomerulosclerosis).

• Secondary Focal Segmental Glomerulosclerosis: Infection, drug toxicity, diabetes, sickle cell disease, obesity, and other kidney diseases can cause secondary focal segmental glomerulosclerosis. Treating or controlling these causes slows kidney damage and improves kidney function over a period of time.

• Genetic Focal Segmental Glomerulosclerosis: This is a rare form of focal segmental glomerulosclerosis caused by genetic factors. It is also known as familial focal segmental glomerulosclerosis. Different family members are affected by the disease. It can also occur when none of the parents have the disease but carry a copy of the gene responsible for it. This gene can be passed on to the next generation.

• Unknown Focal Segmental Glomerulosclerosis: The cause of focal segmental glomerulosclerosis is unclear in certain cases, despite the positive symptoms and tests.

What Causes Focal Segmental Glomerulosclerosis?

The cause of focal segmental glomerulosclerosis is unknown as it is a rare condition. It affects both kids and adults. Men and boys are affected more. It is common in African Americans as well. Focal segmental glomerulosclerosis is vaguely classified based on its cause into:

Primary Focal Segmental Glomerulosclerosis: This condition develops on its own with no particular cause.

Genetic Focal Segmental Glomerulosclerosis: In this condition, the individual has several mutated or altered genes that cause the disease.

Secondary Focal Segmental Glomerulosclerosis: Other factors and certain medical conditions can cause focal segmental glomerulosclerosis sometimes. Various health issues thought to cause secondary focal segmental glomerulosclerosis include:

• Diabetes: The presence of high blood sugar in the body.

• Sickle Cell Disease: This is a group of disorders that affects the shape of the red blood cells.

• Infections: infections such as HIV (human immunodeficiency virus).

• Lupus: This is an autoimmune disease where the body’s immune system attacks its own cells.

• Obesity.

• Hypertension: High blood pressure can cause focal segmental glomerulosclerosis.

• Drugs: Long-term drugs like heroin or muscle-building drugs can cause focal segmental glomerulosclerosis.

• Excess urine in the kidneys.

• Medications: Medicines used during cancer treatments might cause focal segmental glomerulosclerosis.

• Congenital kidney problems.

What Are the Symptoms of Focal Segmental Glomerulosclerosis?

Focal segmental glomerulosclerosis is usually asymptomatic. The doctor usually finds the signs and symptoms incidentally while testing for other conditions.

• Edema: This is the condition where there is swelling of the ankles, legs, and face due to the accumulation of excess fluid in the body.

• High cholesterol.

• Lower than the normal amount of albumin (a protein present in the urine) in the urine.

• Proteinuria: A condition with abnormally high levels of protein in the urine.

• Weight gain due to fluid retention in the body.

How Is Focal Segmental Glomerulosclerosis Diagnosed?

Diagnostic Tests include:

• Blood Test: Blood samples are taken to measure the level of protein and fat.

• Glomerular Filtration Test: This test measures how well the kidneys are working.

• Urine Test: The urine test measures the amount of protein and blood in the urine.

• Kidney Biopsy: Biopsy is the procedure where a little part of the diseased part is scraped off and evaluated under the microscope. Sometimes, genetic testing is done to validate the diagnosis of focal segmental glomerulosclerosis.

How Is Focal Segmental Glomerulosclerosis Treated?

Treatment of focal segmental glomerulosclerosis depends on the type and cause of the disease. Individuals’ overall health and age too determine the treatment modality. The main aim of the treatment is to control the symptoms and slow the progressive scarring of the glomeruli so that kidney failure does not occur. In Individuals with secondary focal segmental glomerulosclerosis, treating the underlying cause of the disease might prevent kidney failure. Glomeruli cannot be repaired, but kidney function might improve. Other treatment modalities include:

• Angiotensin: Converting Enzyme (ACE) Inhibitors: These drugs treat high blood pressure.

• Antibiotics: Antibiotics are prescribed to treat infections.

• Diuretics: These medications are used to lower blood pressure and remove excess body fluids.

• Immunosuppressive Drugs: These drugs suppress the immune system.

• Plasmapheresis: This is a procedure that decreases the number of antibodies by removing the fluid part or plasma from the blood.

• Prednisone: This drug lowers the level of protein in the urine.

What Are the Complications Associated With Focal Segmental Glomerulosclerosis?

If left untreated, focal segmental glomerulosclerosis can lead to high blood pressure and eventually cause kidney failure. This could be life-threatening, requiring medical treatment. Complications include:

• Chronic kidney failure.

• End-stage kidney disease:It is a medical condition where the kidneys stop working.

• Infection.

• Malnutrition.

• Nephrotic syndrome: This kidney disorder causes the body to pass too much protein in the urine.

How Is the Prognosis of Focal Segmental Glomerulosclerosis?

Focal segmental glomerulosclerosis has no definite cure. The prognosis varies from person to person. In some individuals, the disease goes away on its own without treatment. For others, the disease persists over the years without much change. Kidney failure occurs in certain individuals. Such people need a kidney transplant or dialysis.

Conclusion

Focal segmental glomerulosclerosis is a rare disease where the glomeruli or the filters of the kidneys become hard. The exact cause of the condition remains unknown. It affects both children and adults. Males are affected more than females. Treatment of the disease is based on the underlying cause of the disease. Left untreated, it can lead to complete kidney failure requiring dialysis or a kidney transplant. The disease can relapse even after a kidney transplant. But many people with the disease live fulfilling lives. With regular check-ups and blood tests, the progression of the disease is watched.