CD40LG and myeloid sarcoma: The prevalence and titers of the anti-HHV-6A/B IgG in serum were significantly higher in the MS patients [100% (40/40), 51.5 (21.7, 120.4) AU/ml] than in the patients with OND [81% (18/22), 24.4, (14.6, 59.1) AU/ml] (p = 0.013, p = 0.006 respectively), but we did not find any difference for the anti-HHV-6A/B IgM.