What is glomerulonephritis?
Inflammation of the glomeruli, the tubular filters in the kidney, is defined as glomerulonephritis (GN). It can affect any age, ethnicity and gender but is more common in women and children. Glomerulonephritis can be acute or chronic. Acute glomerulonephritis is often related to bacterial infections. The chronic variations are seen with kidney damage due to repeated acute episodes or conditions such as diabetes mellitus or high blood pressure.
What are the symptoms of glomerulonephritis?
In the kidneys, blood is filtered at the glomeruli which are essentially a collection blood capillaries. Glomerular filtration removes excess water, salts and waste (mainly urea and creatinine), forming urine while the now “cleaner” blood is returned to the circulation. Therefore, damage to these capillaries, as in GN, causes :
- Reduced urine output
- Red to dark brown colored urine due to the presence of blood
- Frothy urine because excess protein is excreted
- Retention of salts and water, results in hypertension (high blood pressure) and edema (swelling of the limbs and abdomen due to fluid retention).
Untreated glomerulonephritis may complicate into permanent kidney damage and eventually lead to kidney failure.
What causes glomerulonephritis?
Conditions that may cause acute glomerulonephritis include :
- Streptococcal infections of the throat and upper respiratory tract. This causes post-streptococcal glomerulonephritis where the excess antibodies generated against the Streptococci (bacteria) reach the glomeruli via blood and initiate inflammation.
- Bacterial endocarditis is an infection of the heart valves by the bacterium, Staphylococcus aureus causing damage to the inner lining of these valves. The link between this condition and glomerulonephritis is unclear.
- Viral hepatitis – hepatitis B and hepatitis C.
- Goodpasture syndrome is a rare autoimmune disease which affects the lungs and kidneys and can lead to renal failure within weeks of onset.
- Polyarteritis nodosa and Wegener’s granulomatosis are serious inflammatory destructions of the blood vessels (vasculitis), specifically of the smaller and medium-sized arteries including those supplying the kidneys.
The causes of chronic glomerulonephritis are :
- Diabetic nephropathy is kidney diseases associated with diabetes mellitus. The elevated blood glucose levels culminates in sclerosis (hardening) and scarring in of some glomeruli (focal segmental glomerulosis) or lead to nodular glomerulosclerosis and further kidney dysfunction.
- IgA nephropathy or Berger’s disease is a condition where there is deposition of immunoglobulin A in the glomeruli and causes subsequent inflammation.
- Systemic lupus erythematosus is chronic inflammation that affects several parts of the body, including the kidneys.
- Nephritis associated with AIDS.
- Hypertension – high blood pressure.
- In rare cases, glomerulonephritis may have a genetic basis as observed in thin basement membrane disease and Alport syndrome.
How is glomerulonephritis treated?
Treatment depends on the underlying cause and the stage of the disease. The options include :
- Antibiotics for streptococcal infections.
- Corticosteroids (prednisone) and immunosuppressants for suppressing inflammatory conditions such as lupus, vasculitis and IgA nephropathy.
- Diuretics (furoseimide) to increase the urine output and reduce edema (swelling).
- Antihypertensive drugs such as angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor agonists to lower blood pressure.
- Plasmapheresis for acute, life-threatening inflammations like Goodpasture syndrome. This procedure involves the removal of the circulating antibodies by exchanging the patient’s plasma with plasma from healthy donors.
- Extensive renal damage in severe cases of GN may require dialysis or kidney transplants.