Transient organising pneumonia at the onset of AQP4-antibody neuromyelitis optica spectrum disorder: A case series and literature review

Abstract

Background

Aquaporin-4-antibody Neuromyelitis Optica Spectrum Disorder (AQP4-Ab NMOSD) is an immune-mediated inflammatory central nervous system disease. While AQP4 is widely expressed in other tissues, extra-CNS manifestations are rare, with most cases manifesting as hyperCKemia and myositis. Lung involvement manifesting as organising pneumonia in AQP4-Ab NMOSD has rarely been reported.

Case series

We present 3 patients with AQP4-Ab NMOSD who developed organising pneumonia at the onset of neurological disease. All 3 had area postrema syndrome and 2 developed longitudinally extensive transverse myelitis. The lung changes resolved spontaneously in 1 patient and after immunotherapy in the other 2 patients. We also tabulated the published cases to date in order to highlight the pertinent clinical and paraclinical features of this association.

Conclusion

The close temporal relationship between organising pneumonia and the onset of AQP4-Ab NMOSD suggests that AQP4-Ab autoimmunity is directly involved in the development of organising pneumonia, presumably from the increased susceptibility to AQP4-Ab induced complement-mediated injury in the peripheral tissues of these individuals in light of the current experimental evidence.