Systemic lupus erythematosus (SLE), often called lupus, is a long-term autoimmune disease in which the immune system mistakenly attacks healthy tissues.
Lupus can affect many parts of the body, including the skin, joints, heart, lungs, brain, and kidneys. One of the most serious complications is lupus nephritis, a condition in which the kidneys become inflamed and damaged.
Doctors have traditionally focused on protecting the kidneys in patients who already have lupus nephritis. However, a new study suggests that even people with lupus who do not have kidney disease at diagnosis may still face a higher risk of developing serious kidney problems later in life.
The research was led by Dr. Iftach Sagy from Cambridge University Hospitals NHS Foundation Trust in the United Kingdom and published in the journal Rheumatology.
The researchers examined health records from 1,145 people who had recently been diagnosed with lupus. None of them had lupus nephritis, and all had normal kidney function when the study began. Their health outcomes were compared with more than 91,000 people of similar age, sex, and ethnicity who did not have lupus.
Participants were followed for a median of nearly six years. At the beginning of the study, kidney function was almost identical in both groups. Kidney function was measured using estimated glomerular filtration rate (eGFR), a common blood test that shows how well the kidneys filter waste from the blood.
Despite starting with healthy kidneys, people with lupus were almost twice as likely to develop chronic kidney disease as those without lupus. They were also more than three times as likely to develop end-stage kidney disease, a severe condition in which the kidneys stop working and dialysis or a kidney transplant may be needed.
The study found that lupus patients also had a higher risk of major cardiovascular events, such as heart attack and stroke, as well as a much higher risk of death from any cause during the follow-up period.
The researchers identified diabetes and high blood pressure as the strongest additional risk factors for kidney disease. These conditions are already known to damage the kidneys, and the results suggest they may be especially harmful in people living with lupus.
The findings suggest that doctors should not assume the kidneys are safe simply because lupus nephritis is absent at diagnosis. Regular kidney testing, blood pressure control, diabetes management, and early referral to kidney specialists may help detect problems before permanent damage occurs.
There are some limitations. This was an observational study, meaning it identified associations rather than proving that lupus directly caused the later kidney disease. Other health factors may also have contributed. Even so, the large national database and matched comparison group strengthen confidence in the findings.
Overall, the study highlights the importance of long-term kidney monitoring for everyone with lupus, even those whose kidneys appear healthy when they are first diagnosed.
If you care about kidney health, please read studies about how to protect your kidneys from diabetes, and drinking coffee could help reduce risk of kidney injury.
For more health information, please see recent studies about foods that may prevent recurrence of kidney stones, and eating nuts linked to lower risk of chronic kidney disease and death.
The study was published in Rheumatology.
Source: Cambridge University Hospitals NHS Foundation Trust.
