A recent study published in Advances in Rheumatology has uncovered 2 potential biomarkers which could be used to predict which lupus nephritis (LN) patients are at the highest risk of severe renal outcomes.
Severe renal conditions which can stem from LN are chronic kidney disease (CKD) and end-stage renal disease (ESRD). Right now, over half of all individuals with systemic lupus erythematous (SLE) will eventually develop LN. Of these individuals, between 10 and 25% will at some point face ESRD.
Knowing which biomarkers are most likely to predict these conditions, in this case serum creatinine (sCr) and proteinuria, can help identify risk and ultimately improve patient outcomes. It can also improve how we approach clinical trials.
The Study
There are some biomarkers which have previously been studied in this area. Of these, the best predictor for poor LN outcomes is 24-hour proteinuria (24PTU). sCr has also been studied in combination with 24PTU, but it hasn’t been studied adequately on its own.
This study aimed to evaluate sCr and proteinuria.
This study was a retrospective study including 214 LN patients. 90.6% of these patients were female, which is typical of SLE. The average age of LN diagnosis was 27.3 years and 3/4 were non-white. Most patients had musculoskeletal presentations (82.2%). 73.8% had mucocutaneous presentations. 46.7% had serositis presentations. Finally, 41.5% had leukopenia/lymphopenia presentations.
24PTU and sCr were measured at baseline and at 3 months, 6 months, 12 months, and 5 years.
Determining Cut-offs
The researchers aimed to create cut-off values of these biomarkers to understand exactly when risk levels increase.
In regard to CKD, the team found the best cutoff for 24PTU was .9 g/24 hour and the best cutoff for sCr was .9 mg/dL. Those who had higher levels at the 12 month mark had a higher risk of developing CKD. Those who were below these levels were very unlikely to develop severe kidney disease.
In regard to ESRD, the researchers determined the best cutoff for 24PTU was .9 g/24 hour and the best cutoff for sCr was 1.3 mg/dL.
Evaluating both 24PTU and sCr can therefore help doctors to assess which of their patients are at greatest risk and make the proper changes to their treatment and monitoring plans. The next step is to conduct studies to evaluate what is the precisely best treatment follow-up plan for these patient populations.
You can read more about this study and its findings here.
Reference:
Braga FNHF, das Chagas Medeiros MM, Junior ABV, et al. Proteinuria and serum creatinine after 12 months of treatment for lupus nephritis as predictors of long-term renal outcome: a case-control study. Adv Rheumatol. Published online January 4, 2022. doi:10.1186/s42358-021-00232-1
