BAFF-var as a Biomarker of Response to B-depletive Treatment in Systemic Lupus Erythematosus and Rheumatoid Arthritis

A variant of the TNFSF13B gene, commonly referred to as BAFF-var has been associated with an increased risk of developing immune-mediated diseases, such as Systemic Lupus Erythematosus (SLE) and Rheumatoid Arthritis (RA).This polymorphism leads to the production of higher levels of BAFFs, that in turns are associated with more severe disease, high anti-Sm and anti-dsDNA titre, complement consumption, and increased risk of flare in SLE, and higher disease activity in RA.This is a prospective study aiming to explore the immunological basis of a potential role of BAFF-var as a prognostic biomarker for response to belimumab and rituximab, the main B-depletive treatments, in SLE and RA patients, respectively. More in detail, the study aims to evaluate if the condition of BAFF-var carrier in SLE and RA patients, treated respectively, with belimumab plus standard of care or rituximab influences immunological, molecular and clinical variables, such as: (a) soluble BAFF (BAFFs) cytokine, (b) mRNA-BAFF (c) miRNA-15a (d) B-cell subpopulations (d) disease activity, as assessed by standardized clinimetric tools.

Inclusion Criteria:Age ≥18 yearsSLE diagnosis according to the '97 ACR Criteria / RA diagnosis to the ACR/EULAR 2010 criteriaBelimumab / Rituximab initiation at the enrollment, according to the product indications.Treatment with glucocorticoids stable over the previous 4 weeksTreatment with other immunosuppressant stable over the previous 12 weeksExclusion Criteria:Age < 18 years