Glomeruli are tiny filters in the kidney.
Collectively both kidneys have more than 2 million glomeruli. These glomeruli filter out the waste products from the blood and ultimately this filtrate forms the urine. Glomerulonephritis is the inflammation of these tiny microfilters.
There are many causes of the inflammation of the glomeruli, some of these diseases are systemic (i.e., other parts of the body are involved at the same time) while some occur exclusively in the glomeruli.
The severity and extent of glomerular damage — focal (confined) or diffuse (widespread), determines how the disease will manifest. Mild to moderate malfunction of the glomeruli result in urinary loss of proteins (proteinuria) and blood (hematuria).
When the amount of the protein in the urine is more than three grams a day it is called “nephrotic syndrome”.
In severe cases kidneys are unable to excrete the waste products which accumulate in the blood and patients may present with kidney failure. This kidney failure may be acute when it is sudden in onset or chronic when the inflammation of the glomeruli is for a prolonged time, which may also cause shrinkage of the kidney.
Types of Glomerulonephritis
Inflammation can produce a number of changes in the glomeruli which are determined by taking a tiny piece of the kidney (kidney biopsy) and examining it under the microscope. The final treatment of glomerulonephritis is administered according to the type of the changes in the glomeruli seen in the kidney biopsy.
Causes of Glomerulonephritis
Most of the time, autoimmunity is the cause of glomerulonephritis. Autoimmunity means activation of the body’s defense system (antibodies and white blood cells) against the tissues of the patients own body. With the activation of the defense system, it may attack a single organ like the kidney or it may attack multiple organs.
So glomerulonephritis can occur either as an isolated disease or can occur as a part of a systemic disease.
Systemic Lupus Erythematosus (SLE) is a good example of a systemic autoimmune disease where kidneys are involved due to lupus glomerulonephritis along with involvement of other body systems as well.
A boil on the skin or infection of the throat with a specific bacteria known as “Streptococcus” and infection of the heart valves can activate the immune system against the kidneys manifested as glomerulonephritis