Longer clinical remission leads to better kidney function: Study
Sustained remission of lupus nephritis greatly lowers risk of kidney damage
People with lupus nephritis who are in clinical remission, with no symptoms for at least one year, are 82% less likely to experience impaired kidney function than those who do not remain in remission, a study has found.
Moreover, longer sustained remission increases the odds of patients staying in remission for years, and lowering their risk of a flare, when symptoms of systemic lupus erythematosus (SLE) suddenly appear or worsen.
The study, “Effect of sustained clinical remission on the risk of lupus flares and impaired kidney function in patients with lupus nephritis,” was published in the journal Kidney International Reports.
Left untreated, lupus nephritis can cause kidneys to stop working properly
Lupus nephritis occurs when the kidneys become inflamed and damaged due to lupus, an autoimmune disease in which the immune system attacks the body’s own healthy tissues. Left untreated, the disease can cause the kidneys to stop working properly.
In lupus nephritis, reaching a point where the kidneys appear to get better may help protect their function. However, there haven’t been many studies investigating how disease remission affects the risk to kidney function and the odds of disease flares.
Now, a team of researchers in Italy looked at how likely it is for people with lupus nephritis to achieve sustained clinical remission, how long it lasts, and what factors can help to predict impaired kidney function or flares.
The study included 303 adults (252 women) who received a diagnosis of lupus nephritis at a median age of 28.5 years. Their median estimated glomerular filtration rate (eGFR), a measure of kidney function, was 82.2 milliliters of cleansed blood per minute per body surface, or mL/min/1.73 m2.
Initial treatment consisted of into-the-vein methylprednisolone followed by prednisone (78.2% of patients), or oral prednisone (21.8%). Immunosuppressants were also used for induction (85.1%) or maintenance therapy (71.9%). The antimalarial agent hydroxychloroquine was used by 92 patients (30.4%).
After a median of 1.44 years after the start of treatment, 257 patients (84.8%) achieved sustained clinical remission, defined as an SLE Disease Activity Index-2000 (SLEDAI-2K) score of zero, indicating no active symptoms, and an eGFR greater than 60 mL/min/1.73 m2 lasting for at least one year.
During a median follow-up of 11.1 years, 46 patients (15.2%) did not achieve sustained clinical remission.
Older age (40 years or older) was linked to a higher probability of sustained clinical remission, “suggesting the need for a closer monitoring of young patients since the beginning of the disease,” the researchers wrote.
Other independent predictors of a higher probability of sustained clinical remission included the use of hydroxychloroquine and no signs of hypertension (high blood pressure).
Nearly half of patients in clinical remission sustained it for median 9.5 years
Among the patients who achieved sustained clinical remission, 115 (44.7%) maintained it for a median of 9.5 years and 142 (55.3%) experienced a flare after a median 3.6 years. Over a median of 17.8 years, there were a total of 174 flares.
The probability of sustained clinical remission being maintained was 63% at five years, 47% at 10 years, and 38% at 15 years. After 15 years of remission, there were no large changes in the probability.
The risk of experiencing a flare was 10% when clinical remission lasted less than five years, dropping to 5% when it lasted five to 10 years, and to 2% when it lasted between 10 and 15 years, “suggesting that the longer the [sustained clinical remission], the lower the flare risk,” the researchers wrote.
At their last follow-up visit, 57 patients (18.8%) had impaired kidney function, defined as an eGFR equal to or less than 60 mL/min/1.73 m2 for at least three months. Achieving clinical remission and sustaining it for longer was found to protect against kidney function impairments.
Indeed, patients who achieved sustained clinical remission were 82% less likely to develop kidney function impairments compared with those who didn’t. The probability of impaired kidney function dropped by 17% with each additional year of clinical remission.
Sustained clinical remission “is an achievable goal and should be pursued as the main target in the management of [lupus nephritis],” the team wrote. “The longer the [sustained clinical remission], the higher the chance of its persistence and the lower the risk of SLE flares.”
