IgA nephropathy is a kidney disorder caused by immune complexes and the protein immunoglobulin A (IgA) inside the glomeruli (filters) within the kidney. IgA nephropathy affects how blood is filtered in the small blood vessels of the kidneys. It occurs when these complexes damage the filtering unit (glomerulus) inside the kidneys.
These glomeruli (the singular form is glomerulus), normally filter wastes and excess water from the blood and send them to the bladder as urine. The deposits of the IgA protein complex cause inflammation and damage that prevents this filtering process, leading to blood and protein in the urine, swelling in the hands and feet, high blood pressure, and progressive kidney disease. This chronic kidney disease may progress over a period of 10 to 20 years. If this disorder leads to end-stage renal disease, the patient must go on dialysis or receive a kidney transplant. Risk factors such as high blood pressure or smoking contribute to disease progression, through injury to the blood vessels within the kidneys.
The IgA protein is a normal part of the body's immune system. We do not know exactly what triggers the immune system to cause IgA deposits and other immune protein complexes in the glomeruli. But, since IgA nephropathy may run in families, genetic and environmental factors probably contribute to developing the disease.
Kidney disease usually cannot be cured. Once the tiny filtering units are damaged, they cannot be repaired. Treatment that focuses on slowing the progression of the disease and preventing complications is critical. One complication is high blood pressure, which further damages glomeruli.
Some patients may benefit from limiting protein in their diet to reduce the buildup of waste in the blood. Other lifestyle changes should include managing high blood pressure.
Having excess weight or obesity may contribute to the loss of protein and kidney damage. Losing excess weight may help reduce proteinuria in IgAN. Smoking cessation should also be advised. Medications are available to help reduce damage to the kidney and disease progression. These include steroids and other immunosuppressant or biologic drugs.
For More Information
American Kidney Fund
6110 Executive Boulevard
Rockville, MD 20852
IgA Nephropathy Support Network
964 Brown Avenue
Huntington Valley, PA 19006
National Heart, Lung, and Blood Institute Information Center
P.O. Box 30105
Bethesda, MD 20824-0105
National Kidney Foundation
30 East 33rd Street
New York, NY 10016
Physicians and patients interested in a placebo-controlled, multi-center trial evaluating alternate-day prednisone and fish oil supplements in young patients with IgA nephropathy should call the Central Office of the Southwest Pediatric Nephrology Group at 1-800-345-IGAN.