In many parts of the world, IgA nephropathy is the most common form of glomerulonephritis–a disease that damages the tiny filtering units of the kidney, called glomeruli. The damage caused by IgA nephropathy results from abnormal deposits of a protein called “IgA” in the glomeruli.
One of the kidney’s most important jobs is to filter toxic waste products from the blood, and the glomeruli play a key role in this process. As more glomeruli are damaged by the IgA protein, the kidney progressively loses its ability to clear wastes from the body. In some patients with IgA nephropathy, this loss of kidney function progresses to chronic kidney failure, which requires dialysis treatment or a kidney transplant.
IgA Nephropathy is sometimes called “Berger’s Disease,” because a French physician named Berger was one of the first to describe the disease.
Q. What are the signs and symptoms of IgA nephropathy?
The most common sign is blood in the urine. The amount of blood may be so small that it is only visible with the aid of a microscope. Another common sign is swelling of the feet.
As loss of kidney function progresses, symptoms may include pain in the back below the ribs, increased need to urinate (especially at night), fatigue, nausea, swelling of hands and feet and high blood pressure.
Q. What causes IgA nephropathy?
The causes of IgA nephropathy are not well understood. The disease seems to cluster in certain families and in certain areas of the world. It rarely occurs in people of African heritage. These facts suggest that genetic influences may play a role in the development of the disease.
Q. How is IgA nephropathy diagnosed?
The presence of blood or protein in the urine are a possible sign of IgA nephropathy. A blood test for serum creatinine can be used to calculate glomerular filtration rate (GFR), which tells how well your kidneys are filtering wastes from the blood. To confirm this diagnosis, it is necessary to do a biopsy. The doctor removes a small piece of tissue from the kidney and examines it under a microscope to look for the characteristic IgA deposits in the glomeruli.
Q. How is IgA nephropathy treated?
Efforts to slow the progression of kidney damage may include limiting the amount of protein in the diet and, if present, careful control of high blood pressure through diet and medication. If these treatments are not enough after a few months, then corticosteroids, such as prednisone, may also be considered. Fish oil has also been used as a treatment. Discuss the use of any supplement and medication with your doctor. For patients who develop progressive kidney failure, treatment may consist of dialysis or a kidney transplant.
The success rate of transplants is good in these patients. Even though the IgA deposits reappear in the transplanted kidney in about half the patients within one year after the operation, the signs and symptoms of the disease remain mild. Loss of a transplanted kidney to recurrent IgA nephropathy is uncommon. The milder form of the disease seen after transplantation may be due to the use of anti-rejection drugs such as cyclosporine.
Q. What is the outlook for patients with IgA nephropathy?
Twenty to forty percent of the patients develop end stage kidney failure about 20 years after the disease becomes apparent. Patients who have an increased level of creatinine in their blood at the time of their diagnosis are more likely to develop chronic kidney failure. It is harder to predict which of the patients who have normal levels of creatinine at the time of diagnosis will develop kidney failure. In general, a poor prognosis is expected for those patients who have high blood pressure, high urine protein, and a significant amount of damage present in their biopsy specimen.
Q. What research is being done?
Several centers in the United States and other countries are studying IgA nephropathy. Researchers are investigating the chemical composition of the IgA protein, the rate of production of this protein, possible genetic influences and analysis of the long-term clinical outcome. New treatments for IgA nephropathy are also being investigated.
#Frequency
-United States
IgA nephropathy accounts for about 10% of biopsies performed for glomerular disease in the United States. Prevalence rates are lower in the United States than in Asian countries. These lower rates may be influenced by a conservative approach by nephrologists in the United States, who are reluctant to perform renal biopsies in asymptomatic patients with only mild abnormalities on urinalyses.
-International
Distribution of IgA nephropathy varies in different geographic regions throughout the world. IgA nephropathy is observed in up to 40% of all biopsies performed for glomerular disease in Asia, compared with 20% in Europe and 10% in North America. High prevalence rates are observed in Singapore, Japan, Australia, Hong Kong, Finland, and southern Europe, whereas low prevalence rates are the rule in the United Kingdom, Canada, and the United States.
A study from Scotland found a significant twofold increase in the diagnosis of IgA nephropathy in the patients residing in the most compared with the least deprived areas. The variation was not explained by the demographics of the underlying population.[5]
In Asia, routine urinalyses are performed for schoolchildren, and renal biopsies are performed for patients with asymptomatic hematuria, thus raising the reported prevalence of the disease.
-Mortality/Morbidity
This disorder is thought to follow a benign course in most cases. However, many patients are at risk for slow progression to ESRD, which develops in approximately 15% of patients by 10 years and 20% by 20 years, though these percentages depend on how the disease is defined.
-Race
IgA nephropathy is more common in whites and Asians and is rare in blacks, both in the United States and in Africa. The condition is frequently observed in Native Americans of the Zuni and Navajo tribes.
-Sex
IgA nephropathy is more common in males than in females. Virtually all studies show a male predominance of at least 2:1, with reported ratios of up to 6:1. The higher male predilection is observed in white patients in northern Europe and the United States.
-Age
IgA nephropathy can affect all ages but is most common in the second and third decades of life. Eighty percent of patients are aged 16-35 years at the time of diagnosis. The condition is uncommon in children younger than 10 years.
Source: Different Websites