Diagnostic value of aquaporin 4 antibody in assessing idiopathic inflammatory demyelinating central nervous system diseases in Egyptian patients

Neuromyelitis Optica Spectrum Disorders in Africa: A Systematic Review

BACKGROUND AND OBJECTIVES

Neuromyelitis optica (NMO) is a CNS inflammatory disease that predominantly affects the optic nerves and the spinal cord. It is more frequent in Asian and African populations than in European ones. Data on epidemiology, clinical presentation, additional investigations, and treatment in the African continent are scarce. We aim to (1) collect and analyze published data on neuromyelitis optica spectrum disorder (NMOSD), (2) indicate challenges in the diagnosis and management, and (3) discuss opportunities for future research, education, and policy making, specifically on the African continent.

METHODS

A systematic review was performed in January 2021 with the search terms "Neuromyelitis optica and Africa," "Devic Disease and Africa," and "NMOSD and Africa." We included all study types except case reports, correspondence, or conference abstracts on NMO or NMOSD. Extracted data included study design, country, study period, demographic and clinical characteristics, results of paraclinical investigations, and outcome. Data analysis was performed with descriptive statistics.

RESULTS

We retrieved a total of 79 records, of which 19 were included. Ten of 54 African countries reported a total of 410 cases. Almost half of them were from North African countries. The mean age at diagnosis was 33 years (range 7-88 years), and 75% were female. Transverse myelitis followed by optic neuritis were the most frequent symptoms at the time of presentation. One hundred nineteen patients experienced at least 1 previous relapse, and 106 had a relapsing course after diagnosis. Relapses were treated with IV methylprednisolone. Azathioprine and steroids were used most often as maintenance treatments. Outcomes were rarely described.

DISCUSSION

The majority of studies on NMOSD from the African continent are retrospective, and most countries do not report any data. Our systemic review shows that data derived from patients living in Africa correspond well to what has been previously published in meta-analyses on patients of African ancestry with NMOSD who live outside of Africa, except for a younger age at onset and a lower proportion of females. We advocate for systematic data collection to adequately capture and monitor the burden of NMOSD, for expansion of research efforts and facilities to perform fundamental and clinical research, and for improved access to health care including diagnostics, treatments, and rehabilitation services for people affected by NMOSD in the African continent.

Neuromyelitis optica spectrum disorder in Africa: What is the current state of knowledge?

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is a chronic autoimmune inflammatory disease of the central nervous system, usually involving the optic nerve, brain, and spinal cord. While the disease is believed to be more common among individuals of African descent, the disease landscape across the continent has not been systematically explored. In this study, we carried out a systematic scoping review by synthesizing original studies on NMOSD from Africa.

METHODS

A comprehensive literature search of PubMed (MEDLINE), Scopus, Embase, and Web of Science databases with the search terms 'neuromyelitis optica' and 'Africa' was performed on June 17, 2020. Synthesis of the result was done using narrative analysis.

RESULT

Of the total 133 identified records, 14 eligible studies from Africa were included. Most of the studies were from North African countries (n = 8; 57%); predominantly retrospective descriptive (n = 8; 57%), or case series (n = 3; 21%); and published within the last two decades (n = 13; 93%). The total number of cases in the studies is 332, with a reported female to male ratio of 4:1 and an age range of 12-88 years at disease onset (average of <40 years in 50% of reports). Aquaporin-4 antibodies was tested in 214 cases and found in 61.7%. Three cases had Myelin Oligodendrocyte Glycoprotein antibody test with one of the cases testing positive and was associated with severe optic neuritis. Autoimmune disorders were reported in 23 out of 93 cases from three studies, while a few studies reported infectious disease associations. IV methylprednisolone was the rule during acute attacks from all the studies, while the choice of medication for maintenance varies, possibly depending on availability and cost.

CONCLUSION

The research landscape on NMOSD in Africa, though limited, provides significant insight into the epidemiology, etiology, and clinical characteristics of the disease. Gaps still exist in the knowledge of disease management. Further research focusing on the African context is needed to provide customized evidence-based care to patients with NMOSD.