Distinct serum cytokine profiles in neuromyelitis optica and multiple sclerosis

Multiple sclerosis (MS) is the most common prototypic inflammatory demyelinating disease. Neuromyelitis optica (NMO) is another inflammatory demyelinating disease of the central nervous system that exhibits clinical symptoms mainly associated with optic neuritis and myelopathy. The inflammatory reaction in MS is associated with an upregulation of a variety of T helper 1 (Th1)- or Th17-mediated cytokines. However, NMO and MS are intertwined both clinically and pathologically, which complicates their diagnosis and treatment. The aim of this study was to evaluate the differences in serum cytokine levels in patients with NMO and MS. We collected peripheral serum from patients with these central nervous system demyelinating diseases for the study. A cytometric bead array was used to assess the cytokine levels using flow cytometry. We found more inflammatory [interleukin (IL)-2 and interferon-γ) and anti-inflammatory (IL-4 and IL-10) cytokines in NMO than in MS. The differences in the optimal cutoff points of serum cytokines, including IL-2 ≥5 pg/mL, can differentiate NMO from MS. In conclusion, patients with NMO had an increased Th1-mediated inflammatory response, but similar Th17-mediated inflammation changes compared to patients with MS. Serum cytokine studies can differentiate NMO cases from MS.