Glomerular disease is caused by conditions that affect a specific part of the kidneys called the glomeruli. The glomeruli are a small network of blood vessels that are the “cleaning units” of your kidneys. They filter waste and remove excess fluid from the blood. When the glomeruli are damaged and cannot function as they should, it is called glomerulosclerosis.
Many diseases and conditions can damage the glomeruli. There are two broad terms used to describe many forms of damage to the glomeruli:
- Glomerulonephritis, inflammation (swelling) of the glomeruli.
- Glomerulosclerosis, scarring/hardening of the glomeruli.
- Glomerulosclerosis can damage the kidneys and, in some cases, lead to kidney failure.
How do the glomeruli work in your kidney?
The kidneys, two bean-shaped organs to the left and right of the spine below the rib cage, are your body’s main filters.
The blood enters the kidneys through the arteries. Once in the kidneys, the arteries branch off and the blood passes into the network of small annular blood vessels called glomeruli. Each glomerulus is connected to the opening of a small fluid-collecting tube called a microtubule. Each glomerulus unit is called a nephron. There are about one million nephrons in each of the kidney.
Properly functioning glomeruli work by keeping blood cells and protein circulating in the bloodstream, where your body needs them. Meanwhile, the glomeruli filter waste and excess water, to pass fluid into the tube (which turns into urine). Urine leaves the kidneys through larger tubes called ureters, which carry urine to the bladder.
How does glomerulosclerosis interfere with kidney function?
Glomerular disease damages the glomeruli, affecting their ability to function properly. Instead of retaining protein and red blood cells in the blood, the damaged glomeruli cause some of these products to leak into the urine. One of the functions of blood proteins, such as albumin, is to transport excess fluid from the body into the bloodstream so that it can be filtered by the kidneys and removed from the body as urine. Not having enough protein in your bloodstream keeps excess fluid in your body, causing swelling in areas such as the face, hands, feet, abdomen, and ankles.
The damaged glomeruli also cannot filter waste products and these products begin to build up in the blood.
What causes glomerulosclerosis?
Causes of glomerulosclerosis include:
- An infection, medication, or chemical that is harmful to your kidneys.
- Diseases affecting the whole body, including the kidneys.
- Diseases that cause the swelling or scarring of the nephron or the glomerulus.
- Unknown cause.
What are the signs and symptoms of glomerulosclerosis?
Signs of glomerulosclerosis include one or more of the following:
- The Foamy urine (a sign of the protein in the urine [proteinuria]).
- Pink or light brown urine (a sign of blood in the urine [hematuria]).
- Swelling in your face/around the eyes (especially in the morning), hands, feet, or ankles (especially at the end of the day). This swelling is called edema.
How is glomerulosclerosis diagnosed?
After a thorough physical and medical history, your health care provider will order several tests, including:
- A urine test (urinalysis), to check for a high protein level, presence of red blood cells, and level of white blood cells (may indicate infection or inflammation).
- Blood tests, to check for low levels of protein, creatinine (kidney function) and levels of urea nitrogen (a waste product). A calculation, called the glomerular filtration rate (GFR), is done to determine if your kidneys are filtering properly.
If these lab tests indicate kidney damage, your health care provider may order:
- Additional blood tests for possible causes such as infections or autoimmune diseases.
- Imaging tests, including ultrasound, to see if the shape or the size of the kidneys is abnormal.
- Kidney biopsy, which involves using a needle to remove small pieces of tissue for viewing under a microscope.
What diseases and conditions cause glomerulosclerosis and how are they treated?
Many diseases can lead to glomerulosclerosis. The goal of treatment is to treat the underlying cause (if it can be identified) to protect your kidneys from further damage. Here are some general categories of diseases that can cause glomerulosclerosis and examples and treatments for each.
Autoimmune diseases
These are diseases in which the body’s immune system attacks itself. These diseases can affect your entire body or may attack only certain organs or areas of your body. Autoimmune diseases that affect the kidneys which include:
1. Systemic lupus erythematosus (SLE) (also known as lupus)
This autoimmune disease affects many parts of the body. In the kidneys, it causes lupus nephritis, an inflammation of the glomeruli. The inflammation causes scars that prevent the kidneys from working properly. Anti-inflammatory treatment includes immunosuppressive drugs such as mycophenolate mofetil or cyclophosphamide with the corticosteroid prednisolone.
2. Goodpasture’s Syndrome
An autoimmune disease: that attacks the kidneys and lungs. In the kidneys, it causes glomerulonephritis, which is an inflammation of the glomeruli and can lead to permanent kidney damage. Treatments include immunosuppressive medications and plasmapheresis (a process to remove the antibodies that attack your body).
3. IgA nephropathy
With this autoimmune disease, a specific part of the immune system called immunoglobulin A (IgA) antibodies forms deposits in the glomeruli. These deposits cause inflammation. Treatments include ACE inhibitors or angiotensin receptor blockers.
4. Hereditary nephritis
Alport syndrome: It is an inherited condition that causes chronic glomerular disease along with impaired hearing or vision. It affects both men and women. Men suffer more from chronic kidney disease, which can be diagnosed in their twenties; Total kidney failure most often occurs around the age of 40. Treatments include medications to control the blood pressure.