Clinical Characteristics of Aquaporin 4 Auto-antibody Positive Patients – A Case Series

  • Dr Stefan Blum, Department of Neurology, Royal Brisbane and Women's Hospital, Australia
  • Dr Richard Wong, Division of Immunology, Pathology Queensland – Central Laboratory, Royal Brisbane and Women's Hospital, Australia
  • Dr David Gillis, Division of Immunology, Pathology Queensland – Central Laboratory, Royal Brisbane and Women's Hospital, Australia
  • Mr Bob Wilson, Division of Immunology, Pathology Queensland – Central Laboratory, Royal Brisbane and Women's Hospital, Australia
  • Mrs Kerryn Prain, Division of Immunology, Pathology Queensland – Central Laboratory, Royal Brisbane and Women's Hospital, Australia
  • Prof Pamela McCombe, Department of Neurology, Royal Brisbane and Women's Hospital, Australia

Introduction: Neuromyelitis optica is an idiopathic, autoimmune, demyelinating disease of the central nervous system. It has been associated with an autoantibody to Aquaporin 4, labelled NMO-IgG.
Methods: We have been performing testing of NMO-IgG titers in our laboratory since 2007; 10 patients tested positive. Full clinical records were obtained for the patients who tested positive.
Results: All of our NMO-IgG positive patients were female. Positivity for NMO-IgG was associated with severe clinical relapses in 7 patients. There was a history of auto-immune disease or positivity for markers of antibody mediated auto-immunity in 7 patients. There was clinical evidence of spinal cord disease with the MRI spine showing long spinal cord lesions in all of our patients. Optic neuritis occurred in 5 of 10 patients. MRI brain showed multiple T2 hyperintensities in 5 patients. Oligoclonal bands were positive in 2 of 6 patients in whom this test was performed.
Conclusion: Positivity for NMO-IgG is associated with severe clinical relapses and long spinal cord lesions on MRI spine. A diverse range of other auto-immune diseases is commonly found. Female gender appears to be a risk factor for positive NMO-IgG in our group.