Peripheral blood monocyte count at onset may affect the prognosis in multiple sclerosis.

Multiple sclerosis (MS) is a demyelinating neurological disease with unknown causes. In this study, we comprehensively studied blood cell counts in the early phase of MS and compared their values with eventual prognostic variables. We found that the blood monocyte count in the early phase of MS was robustly associated with the clinical severity of MS (rho = 0.64; p = 0.0002) but that the counts of the other blood cells were not associated with severity. This correlation between monocyte count and severity was not observed in neuromyelitis optica. In conclusion, blood monocytes could be a candidate for the prognostic prediction of MS.