Tuberculous nephritis accompanying neuromyelitis optica: causal or coincidental association?

Neuromyelitis optica and concomitant pulmonary tuberculosis: a case report

Background

Concomitant diagnosis of neuromyelitis optica spectrum disease and pulmonary tuberculosis has rarely been reported.

Case report

We report a case involving a young Tunisian male patient who developed dry cough followed, 2 months later, by weakness in the lower limbs. The findings of central nervous system imaging and anti-aquaporin-4 antibody positivity were compatible with the diagnosis of neuromyelitis optica spectrum disease. Constellation of the clinical and the typical radiological pulmonary findings in our patient, coming from an endemic region, allowed the diagnosis of pulmonary tuberculosis, although sputum smear examination for acid-fast bacilli and cultures was negative. The patient received anti-tuberculous polytherapy associated with immunomodulation, consisting of methylprednisolone and intravenous immunoglobulins. Pulmonary infection symptoms initially improved but with no motor recovery. The patient suddenly died at home 4 months after the onset of the first symptoms. Current data regarding the clinical presentation of this underreported concomitant or associated condition, the possible pathophysiological mechanisms, and the therapeutic options were reviewed.

Conclusions

This case underscores the necessity to understand the exact mechanism of these coincident entities and to clarify the best immunomodulatory choice since immunosuppression targeting neuromyelitis optica spectrum disease can lead to dissemination of pulmonary tuberculosis.

Devic's neuromyelitis optica associated with active pulmonary tuberculosis, Tunisia

Devic's Optic neuromyelitis (OND) is a very rare disease defined as a central nervous system (CNS) inflammation resulting in optic neuritis and/or myelitis. The discovery of a highly specific serum autoantibody biomarker for the diagnosis has triggered a great interest in conducting further research into this disease. The association of OND with Tuberculosis (TB) is even rarer and could be an entirely random conjunction. To our knowledge, we reported the first case of Neuromyelitis Optica associated with pulmonary TB in Tunisia.

Neuromyelitis optica spectrum disorder and active tuberculosis

Tuberculosis is on the rise again. It brings with it potential for neurological involvement both as a direct infection and as a parainfectious process. Accordingly we report the development of neurological problems affecting a 48-year-old patient's vision and sensation while being treated for active tuberculosis. At its nadir her vision deteriorated to nil perception of light and she had a sensory level to T10. Neuromyelitis optica spectrum disorder was diagnosed. We discuss our management strategy with neuromodulation in the context of active tuberculosis infection.

Pathogenic implications of cerebrospinal fluid barrier pathology in neuromyelitis optica

Pathogenic autoantibodies associated with neuromyelitis optica (NMO) induce disease by targeting aquaporin-4 (AQP4) water channels enriched on astrocytic endfeet at blood–brain interfaces. AQP4 is also expressed at cerebrospinal fluid (CSF)–brain interfaces, such as the pial glia limitans and the ependyma and at the choroid plexus blood–CSF barrier. However, little is known regarding pathology at these sites in NMO. Therefore, we evaluated AQP4 expression, microglial reactivity, and complement deposition at pial and ependymal surfaces and in the fourth ventricle choroid plexus in 23 autopsy cases with clinically and/or pathologically confirmed NMO or NMO spectrum disorder. These findings were compared to five cases with multiple sclerosis, five cases of choroid plexus papilloma, and five control cases without central nervous system disease. In the NMO cases, AQP4 immunoreactivity was reduced relative to control levels in the pia (91%; 21/23), ependyma (56%; 9/16), and choroid plexus epithelium (100%; 12/12). AQP4 immunoreactivity was normal in MS cases in these regions. Compared to MS, NMO cases also showed a focal pattern of pial and ependymal complement deposition and more pronounced microglial reactivity. In addition, AQP4 loss, microglial reactivity, and complement deposition colocalized along the pia and ependyma only in NMO cases. Within the choroid plexus, AQP4 loss was coincident with C9neo immunoreactivity on epithelial cell membranes only in NMO cases. These observations demonstrate that NMO immunopathology extends beyond perivascular astrocytic foot processes to include the pia, ependyma, and choroid plexus, suggesting that NMO IgG-induced pathological alterations at CSF–brain and blood–CSF interfaces may contribute to the occurrence of ventriculitis, leptomeningitis, and hydrocephalus observed among NMO patients. Moreover, disruption of the blood–CSF barrier induced by binding of NMO IgG to AQP4 on the basolateral surface of choroid plexus epithelial cells may provide a unique portal for entry of the pathogenic antibody into the central nervous system.