HP and primary progressive multiple sclerosis: This high level of reactivity of anti-Hp hsp60 at SPMS may support the recent evidence that B cells and antibodies play an important role at pathogenesis of progressive forms of MS and that compartmentalized CNS inflammation is one of the driving processes behind neurodegeneration and progression at MS; such theory is consolidated by identification of meningeal ectopic B cell follicles in SPMS patients and by successful use of B cell depleting therapy in PPMS patients [16].