Researchers of this study found the renal activity index for lupus successfully measured lupus nephritis in a noninvasive manner using specific urine biomarkers excreted during kidney biopsy.
Hermine I. Brunner, MD, MSc, MBA, from the Cincinnati Children’s Hospital Medical Center and University of Cincinnati College of Medicine in Cincinnati, and colleagues evaluated traditional laboratory tests and 16 urine biomarkers (UBM) of 47 children with lupus nephritis (LN) who underwent a kidney biopsy, according to the abstract. The researchers used the HIH activity index (NIH-AI) and the tubulointerstitial activity index (TIAI) to measure histologic activity, in which a NIH-AI score of greater than 10 or TIAI scores of greater than 5 were associated with high LN-activity status and scores of no more than 10 and no more than 5, respectively, were associated with moderate or low activity statuses.
They found six UBMs excreted by patients with LN predicted disease activity (monocyte chemotactic protein 1, hemopexin, neutrophil gelatinase–associated lipocalin ceruloplasmin, adiponectin, and kidney injury molecule 1) for NIH-AI at greater than 92% accuracy and TIAI at greater than 80% accuracy, according to the abstract. Without standardization of UBMs, Brunner and colleagues found accuracy ranged between 71% and 85% and that concomitant LN damage minimally influenced renal activity index for lupus (RAIL) accuracy. They also noted principal component and linear discrimination analyses confirmed the strength of UBMs as predictors of LN disease status.
The researchers hypothesized the RAIL may be able to noninvasively monitor the degree of inflammation in patients with lupus nephritis, if this method is validated.
“If confirmed in ongoing experiments, the RAIL will allow for more effective and personalized monitoring of LN and its therapy. The availability of standardized clinical platforms for the combined measurement of the urinary biomarkers will enable the testing of this hypothesis in the near future,” Brunner and colleagues wrote in their study. “Future research will need to confirm the most appropriate cutoff scores for the RAIL and also investigate how the combinatorial RAIL UBMs can be used to noninvasively predict response to therapy.” – by Jeff Craven
Disclosures: Brunner reports consulting fees, speaking fees, and honoraria from Biogen/Idec, Bristol-Myers Squibb, GlaxoSmithKline, and MedImmune/AstraZeneca. Please see the full abstract for a list of all other authors’ relevant financial disclosures.