Lupus Awareness Month in May was established to increase public awareness and understanding of this autoimmune disease. Many people still know very little about lupus and its detrimental impact on the body. A key aspect of the disease that often goes unnoticed is kidney damage.
Baylor College of Medicine‘s Dr. Rajeev Raghavan explains the impact that lupus can have on your kidneys.
“We don’t know what causes lupus, but it is believed to be secondary to a number of different factors, such as genetic, environmental or hormonal factors. The result is that lupus affects multiple organ systems, including the kidneys,” Raghavan, associate professor of medicine at Baylor College of Medicine in Houston, Texas, said in a press release.
Kidneys are the key organs that filter waste products from the blood, one of their main functions. They also control the body’s fluid balance and regulate vitamin D levels and hormones that help control blood pressure and blood volume.
“Since lupus is an autoimmune disease, the result is antibody formation, which attack organs, including the kidneys, and result in inflammation,” Raghavan said. “Around 40 percent of patients with lupus have kidney disease, and this is detectable by examining the urine for blood or protein.”
The signs of kidney disease usually appear within the first five years after the start of lupus symptoms, and a final diagnosis is performed after a kidney biopsy (a kidney sample is taken from the body so it can be closely examined).
This procedure allows clinicians to understand the type of lupus affecting the patient as well as the stage of the disease. These results offer a tailored therapy according to each patient who has developed lupus-induced kidney damage, a condition called lupus nephritis.
“When you have lupus nephritis [kidney inflammation caused by lupus], the treatment is quite effective – only about 5 to 10 percent of those patients will progress on to really advanced kidney failure where they need dialysis or a kidney transplant,” Raghavan said.
Currently, there are two treatment options. In the first, which is called non-selective, patients are given the same therapy as other diseases that show protein or blood in their urine, signs of kidney damage. This strategy includes restricting sodium intake to about 2.3 grams per day and controlling blood pressure so that it stays around 130 over 80. It may also include medications, if necessary, such as angiotensin converting enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARBs).
Another treatment option uses medications that target the immune system with the objective of decreasing its activity.
Unfortunately, there are no options for preventing lupus patients from developing kidney disease.
“All we know is that if you have kidney disease because of lupus, we have medications to control and treat the disease,” Raghavan said. “Early diagnosis and treatment results in a high success rate in the sense that very few treated patients will require dialysis or transplantation.”