Background Post-hoc analyses from the BLISS trials demonstrated that patients with high baseline B-lymphocyte stimulator (BLyS) levels (≥2 ng/ml) had an increased risk of a clinically meaningful flare over 1 year.1
Objectives Given that BLyS levels are not routinely collected in clinical practice, further analyses were conducted to identify clinical variables that may be predictive of high BLyS levels.
Methods Data from BLISS-52 (NCT00424476) and BLISS-76 (NCT00410384) were pooled (GSK200619). All randomised subjects with baseline BLyS levels were included. A logistic regression analysis was performed. A univariate logistic regression was first employed to identify a subset of baseline factors (e.g. demographic, disease activity, laboratory, biomarker and systemic lupus erythematosus [SLE] medication usage) predictive of high baseline BLyS levels. Only baseline factors that were significant at the 0.05 level entered the final logistic regression as covariates.
Results A total of 380 out of 1664 (22.8%) subjects had high baseline BLyS levels (≥2 ng/ml). Most subjects were female (n=344, 90.5%); mean age was 36 (11.0 SD) years, and mean SELENA-SLEDAI score was 10.8 (4.29 SD). Significant baseline predictors of high baseline BLyS levels included positive anti-Smith (≥15 U/ml; χ2 =17.04, p<0.01), low C3 (χ2 =4.81, p<0.05), anti-dsDNA (>200 IU/ml; χ2 =20.41, p<0.01) and anti-dsDNA (80–200 IU/ml; χ2 =5.85, p<0.05), use of immunosuppressant medication (χ2 =27.39, p<0.01), proteinuria (≥0.5 g/24 h; χ2 =18.91, p<0.01) and elevated C-reactive protein (>3 mg/L; χ2 =51.61, p<0.01).
Conclusions Positive anti-Smith, low C3, positive anti-dsDNA, immunosuppressant usage, proteinuria and elevated C-reactive protein were predictors of high BLyS levels. Identifying routinely collected clinical variables predictive of high BLyS levels, which are associated with moderate-to-severe flare and high disease activity, is useful in the ongoing management of SLE.
Disclosure of Interest D. Roth Shareholder of: GlaxoSmithKline, Employee of: GlaxoSmithKline, A. Thompson Shareholder of: GlaxoSmithKline, Employee of: GlaxoSmithKline, T. Tang Shareholder of: GlaxoSmithKline, Employee of: GlaxoSmithKline, A. Hammer Shareholder of: GlaxoSmithKline, Employee of: GlaxoSmithKline, C. Molta Shareholder of: GlaxoSmithKline, Employee of: GlaxoSmithKline