MPO and neuromyelitis optica: ANA: anti-nuclear antibodies, ANCA: anti-neutrophilic cytoplasmic autoantibody, TBE: tick-borne encephalitis, HTLV: human T-lymphotropic virus, MOG: myelin oligodendrocyte glycoprotein, MPO: myeloperoxidase, NMO: neuromyelitis optica, PR3: proteinase 3, RRMS: relapsing-remitting multiple sclerosis, QFN: Quantiferon.