Increased levels of APRIL (A Proliferation-Inducing Ligand) mRNA in multiple sclerosis

B cells play an indispensable, yet indeterminate, role in the pathogenesis of multiple sclerosis (MS). We measured mRNA of APRIL–a promotor of B-cell survival–in peripheral blood and quantified protein levels in plasma and cerebrospinal fluid in MS patients and controls. APRIL mRNA levels in monocytes and T cells were significantly higher in MS patients than in controls. Levels of soluble APRIL in plasma were higher in patients with chronic progressive MS than in patients with relapsing–remitting MS, albeit not significantly. MS may thus be associated with increased transcription in peripheral blood of factors promoting B-cell survival, including APRIL.