Kidney relapses are a major driver of long-term kidney function loss in lupus nephritis patients, according to new research analyzing nearly five decades of real-world patient data. A study of 131 patients with biopsy-confirmed lupus nephritis found that while 80% achieved complete remission within the first year of treatment, those who experienced relapses suffered significantly faster kidney function decline over time .

Why Do Kidney Relapses Matter So Much in Lupus Nephritis?

Lupus nephritis is a serious kidney complication of systemic lupus erythematosus, an autoimmune disease where the body attacks its own tissues. When lupus affects the kidneys, it can cause inflammation and damage that impairs their ability to filter waste from the blood. Researchers from Maastricht University in the Netherlands analyzed patient records spanning from 1977 to 2024, with an average follow-up period of 11.2 years, to understand what determines long-term kidney health outcomes .

The findings challenge conventional thinking about how to predict kidney disease progression. While doctors have traditionally relied on proteinuria (protein in the urine) as a warning sign, the study revealed that residual proteinuria alone does not reliably predict whether a patient's kidney function will decline. Instead, kidney relapses emerged as the principal factor determining long-term kidney function loss .

What Do the Numbers Show About Relapse Impact?

The research revealed striking differences in kidney function decline between patients who experienced relapses and those who remained relapse-free. Patients who had at least one kidney relapse experienced a steeper annual decline in estimated glomerular filtration rate (eGFR), a key measure of kidney function, of 2.47 milliliters per minute per 1.73 square meters compared to relapse-free patients. To put this in perspective, each additional relapse beyond the first caused an additional yearly decline of 1.39 milliliters per minute per 1.73 square meters .

Within the first year of treatment, 89% of patients achieved partial remission and 80% achieved complete remission, suggesting that initial treatment responses are generally strong. However, despite these high early success rates, 19% of patients progressed to end-stage kidney disease requiring dialysis after a median of 10.4 years. Kidney relapses occurred in 42% of patients, typically about 3.1 years after their initial diagnosis .

How to Monitor and Prevent Kidney Relapses in Lupus Nephritis

• Regular kidney function testing: Patients should undergo periodic eGFR measurements and urinalysis to detect early signs of relapse, even when feeling well, since repeat biopsies showed progressive damage in patients considered to be in remission.
• Baseline and ongoing risk assessment: Higher serum creatinine levels, greater activity scores on kidney biopsies, and higher chronicity scores were independently associated with progression to end-stage kidney disease, making these important markers to monitor.
• Relapse prevention through novel therapeutics: The study emphasized the need for improved disease monitoring and prevention of kidney relapses through newer medications, as maintaining remission is critical to preserving long-term kidney function.

The research also revealed a concerning finding about patients in remission. Repeat kidney biopsies showed that chronicity scores, which measure permanent structural damage to the kidney, continued to increase even among patients considered to be in remission. This suggests that ongoing subclinical injury occurs beneath the surface, highlighting why prevention of relapses is so important .

"In this real-world cohort, high remission rates were achieved with only few patients retaining residual proteinuria. Patients maintaining remission fare well, whereas kidney relapses cause additional yearly eGFR decline. Repeat biopsies reveal progression in chronicity even in remitted patients, highlighting the need for improved disease-monitoring and prevention of kidney relapses through novel therapeutics," stated Wessel Vos, PhD, of Maastricht University.

Wessel Vos, PhD, Maastricht University

What Does This Mean for Lupus Patients?

For the millions of people living with lupus, these findings underscore the importance of aggressive relapse prevention and close medical follow-up. The study demonstrates that achieving initial remission is not enough; the long-term trajectory of kidney health depends heavily on whether patients experience additional relapses. This means that lupus patients with kidney involvement should work closely with their nephrologists to identify and prevent relapses before they occur, rather than waiting for symptoms to appear .

The research also suggests that current monitoring approaches may need updating. Since proteinuria levels alone do not reliably predict kidney function decline, doctors may need to incorporate additional markers and more frequent kidney biopsies to catch early signs of relapse. This proactive approach could help preserve kidney function and delay or prevent progression to end-stage kidney disease in lupus nephritis patients .