BAFF-APRIL (human) Heteromers ELISA Kit

BAFF (B cell-activating factor; BLyS; B lymphocyte stimulator; TNFSF13B; TALL-1; CD257), belonging to the TNF family, is a master regulator of peripheral B cell survival and, together with IL-6, promotes Ig class-switching and plasma cell differentiation. BAFF co-stimulates activated T cells. Increased levels of soluble BAFF have been detected in the serum of patients with various autoimmune diseases, such as Sjögren’s syndrome, rheumatoid arthritis, multiple sclerosis and systemic lupus erythematosus (SLE). Furthermore, BAFF is found in inflammatory sites in which there is lymphoid neogenesis. BAFF levels are elevated in patients with multiple myeloma and B cell chronic lymphoid leukemia (B-CCL).

APRIL is a secreted cytokine, belonging to the TNF superfamily that binds to transmembrane activator and CAML interactor (TACI), B cell maturation antigen (BCMA) and can interact with carbohydrate side chains of heparan sulfate proteoglycans (HSPG) that may trigger cross-linking. APRIL maintains B cell homeostasis by acting at a later stage, modulating the function and survival of antigen-experienced B cells. APRIL (as well as BAFF) stimulates class-switch recombination (CSR), hence contributes to shaping humoral effector mechanisms. With regards to humoral memory, APRIL is involved in the establishment and survival of the long-lived plasma cell (LLPC) pool in the bone marrow (BM). APRIL might also function in enhancing proliferation of some tumor cells, especially B cell malignancies. Recently, APRIL has been shown to confer atheroprotection via binding to heparan sulfate (HS) chains of heparan-sulfate proteoglycan 2 (HSPG2), which limits LDL retention, macrophage accumulation and necrotic core formation.

BAFF and APRIL also exist as heteromers of BAFF and APRIL that are produced in autoimmune diseases. Sometimes these heteromers can also be detected in healthy subjects.