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.