B-cell subset changes and clinical predictors of telitacicept response in SLE patients with antiphospholipid antibody positivity: a prospective observational cohort study

ObjectiveTo characterize the dynamic changes in B-cell subsets in Systemic lupus erythematosus (SLE) patients with antiphospholipid antibody (aPL) positivity treated with telitacicept and to identify baseline predictors of treatment response.MethodsTwenty patients with active aPL-positive SLE receiving telitacicept in addition to standard therapy were enrolled, and 20 healthy individuals served as controls. Peripheral blood B-cell subsets and clinical parameters were assessed at baseline, week 12 and week 24.

B cell subsets were analyzed using flow cytometry. Multivariable logistic regression was used to identify baseline predictors of SRI-4 response at week 24.ResultsAt baseline, the proportions of double-negative (DN) B cells and plasmablasts among total B cells were significantly higher in patients with aPL-positive SLE than in healthy controls (both p < 0.001).

During the treatment of telitacicept, DN B-cell proportions decreased significantly by week 12 and continued to decline over 24 weeks, while plasmablast proportions decreased significantly by week 24; absolute counts of both subsets did not change significantly but showed a downward trend.