The expression of BAFF-binding receptors is not altered in multiple sclerosis or myasthenia gravis.

Multiple sclerosis (MS) is a chronic, progressive disease of the central nervous system (CNS) characterized by consistent myelin injury. Antibody-mediated death of oligodendrocytes is a pathological feature in a subset of MS patients and may be of relevance to disease pathogenesis. In myasthenia gravis (MG), acetylcholine receptors (AChR) situated at the neuromuscular endplate are destroyed by autoreactive antibodies. B-cell activating factor of the tumour necrosis factor (TNF) superfamily (BAFF) is essential for B-cell survival. Using flow cytometry, we evaluated the expression of three BAFF-binding receptors, namely, BAFF-receptor (BAFF-R), B-cell maturation antigen (BCMA), and transmembrane activator and calcium modulating and cyclophilin ligand interactor (TACI) in peripheral-blood lymphocytes. Nearly all CD19(+) B cells and CD19(+)CD27(+) memory B cells expressed BAFF-R. The intensity of BAFF-R expression was not statistically different in MS or MG compared with healthy controls. Very few T cells expressed BAFF-R. BCMA expression was strictly limited to B cells. Although both B and T cells expressed TACI, levels were much higher on B cells compared with levels on T cells. The percentages of B and T cells expressing BCMA and TACI did not differ significantly in MS or MG versus controls. We conclude that the expression of BAFF-binding receptors is not appreciably altered in MS or MG.