Many diseases that influence and damage kidney function attack the glomeruli, tiny cells of the kidney that are responsible for cleaning and purifying the blood. Working much like a sieve, glomeruli are small but complex structures designed to keep the right components in and release others into the urine. Damaged glomeruli can trigger a variety of issues including leakage of protein (albumin) and red blood cells into the urine or the backup of waste products in the blood stream. Leaked albumin can lead to lower than normal blood levels of the essential protein; altering fluid balance in the body leading to swelling of the hands, feet and face. Advanced glomerular disease may lead to kidney failure.
There are a variety of genetic and environmental factors that can trigger glomerular disease and will lead to one of two forms of glomerular dysfunction:
- Glomerulonephritis: Inflammation of the membrane tissue in the kidney that filters wastes and fluids from the blood.
- Glomerulosclerosis: Scarring or hardening of the glomeruli making filtering difficult or impossible.
Glomerular diseases may be caused by a variety of different factors and conditions, many of which are somewhat rare. Infection, toxic drug exposure or diseases that affect the entire body, like diabetes or lupus may all impact kidney function. One or more environmental and physical factors can also work together to damage the glomeruli.
- Goodpasture syndrome
- Autoimmune diseases
- Lupus (Systemic lupus erythematosus)
- IgA nephropathy
- Hereditary nephritis (Alport syndrome)
- Bacterial endocarditis
- Systemic streptococcal exposure
- HIV and others
Symptoms of glomerular diseases may include the following:
- Blood in the urine (hematuria).
- Protein in the urine (proteinuria).
- Reduced GFR (glomerular filtration rate).
Swelling (edema) of the hands, face, feet or other parts of the body.
Patients may not experience any other symptoms of a glomerular disorder and may not know that protein or blood is present in the urine without seeing a healthcare provider. However, changes in urine’s color or other properties may be a warning sign. These include:
- Foaming urine (may indicate protein in the urine).
- Pink or cola-colored urine may indicate the presence of blood.
The first line of testing for glomerular disease is a urinalysis. This simple test will identify abnormally high levels of protein and blood in the urine and guide medical providers in additional testing. Blood tests for creatinine and urea nitrogen will show filtering capacity of the kidneys. Renal imaging with ultrasound or X-ray may reveal changes in the size of the kidney. Due to the microscopic size of the glomeruli, a biopsy may be needed to diagnose a glomerular disease.
Treatment for glomerular disease will depend on its cause, and whether patients have an acute (sudden) or chronic (long-term) form of the disease. Some types of glomerular inflammation (nephritis) will resolve spontaneously. Cases that develop after strep infection is one such example. Other treatments will include:
- High blood pressure: One or a combination of medications to control excess fluid and lower blood pressure to reduce stress on the kidneys.
- Lupus: Steroids or immune-suppressing drugs.
- Strep: Antibiotics.
- Goodpasture syndrome: Replacement of antibodies from the blood’s plasma and replacing it with donated plasma or other fluids.
Patients who develop acute renal failure may need dialysis to do the work of the kidneys. Some cases may progress to end stage renal disease (ESRD) at which point dialysis or a kidney transplant are the only options for survival.