Kitley J, Waters P, Woodhall M, et al. Neuromyelitis optica spectrum disorders with aquaphorin-4 and Myelin-oligodendrocyte glycoprotein antibodies: a comparative study.
see Levy M. Does aquaphorin-4-seronegative neuromyelitis optica exist? (editorial) JAMA Neurology 2014; 71:271-2.
Authors of both studies ferret out a subtype of seronegative NMO that is actually yet another disease. Anti MOG positve patients with clinical features of NMO have a slightly different phenotype with features of ADEM also. This group encompasses young males with severe episodes with better recoveries that are more likely to be monophasic, sometimes with simultaneous or rapidly sequential optic neuritis and transverse myelitis.. AntiMOG patients also had more conus involvement on spine MRI and more involvement of deep gray nuclei on brain MRI. There were no patients with both anti MOG and anti AQU4 antibodies. anti MOG antibodies are available at Neuroimmunology Testing Service, Oxford, England for 30 pounds). "n" of the study was 10 aq-4 patients and 9 MOG AB patients.
More clinical information: 4/9 anti MOG and 6/20 AQU$ AB patients had ON as initial invoolvement or part of ; anti MOG had more bilateral ON involvement (75 v. 33 %); both had severe ON when it did happen. 12/20 AQU$ 4 and 9/9 antiMOG had spinal cord involvement initially; Transverse myelitis differed with more bladder involvement in anti MOG patients as iniital symptom (33 v. 0 %) and more late sphincter disturbance in NMO ab patients. Brain MRI was more likley to be ADEM like in MOG ab patients (44 %) v. 0 % in NMO.