The Prevalence of Long Spinal Cord Lesions and Anti-Aquaporin 4 Antibodies in Neuromyelitis Optica Patients in Taiwan

Abstract

Background and Objective: It was the aim of this study to determine the prevalence of anti-aquaporin 4 antibody (anti-AQP4 Ab) and long spinal cord lesions in neuromyelitis optica (NMO) and multiple sclerosis (MS) patients in Taiwan. Asia has a relatively high rate of NMO compared with MS patients. Anti-AQP4 Ab is an important marker for NMO worldwide, but serological data and clinical profiles of NMO patients in Taiwan have not been reported. Methods: This retrospective study compared the clinical symptoms, demographics, spinal cord lesion length and AQP4 Ab status of 34 patients with NMO with 34 patients diagnosed with conventional MS. Results: Our NMO patients were predominantly middle-aged women (median age 45 years), exhibited many relapses (1.0/year) and displayed a higher Expanded Disability Status Scale score (4.75) than conventional MS patients. NMO patients exhibited long spinal cord lesions as detected by MRI. Forty-one percent of the NMO patients had detectable anti-AQP4 Ab. The Expanded Disability Status Scale score was significantly higher in AQP4 Ab– NMO patients. Conclusion: The prevalence of AQP4 Ab in a Taiwanese NMO group was 41%. Long spinal cord lesions and detection of AQP4 Ab helped to differentiate NMO patients from MS patients. Long spinal cord lesions with the anti-AQP4 Ab test may allow for an earlier diagnosis of NMO and improve therapeutic decisions.

Combined Screening for Serum Anti-Nuclear and Anti-Aquaporin-4 Antibodies Improves Diagnostic Accuracy for Distinguishing Neuromyelitis Optica from Multiple Sclerosis

“…Sensitivity and specificity values using the AQP4-Ab test alone (56.9 and 95.6%, respectively) were broadly similar to those reported previously [6,9,18,19,20,25,26,27,28,29,30,31,32]. For example, sensitivity and specificity values of 56 and 99% were reported in a Dutch cohort [29], while other studies have reported values of 71 and 91% in Chinese patients [26], 58 and 100% in Japanese patients [9], and 73 and 91% in patients from the USA [9].…”

“…For example, sensitivity and specificity values of 56 and 99% were reported in a Dutch cohort [29], while other studies have reported values of 71 and 91% in Chinese patients [26], 58 and 100% in Japanese patients [9], and 73 and 91% in patients from the USA [9]. Furthermore, AQP4-Ab seropositivity in NMO was 78% in Caucasian Germans [28], 68% in a mixed American cohort [27], 62% in Danes [6], 41% in Taiwan [30], 60% in Hong Kong [31] and 64% in Brazilians [32], suggesting ethnic differences, although these variations may also reflect differences in antibodies, test methods, and/or cutoff values. Three studies compared various assays for AQP4-Ab seropositivity and concluded that cell-based assays were superior to other methods, with sensitivities of 74-86% [18,19,20].…”

Elevated plasma high-mobility group box 1 protein is a potential marker for neuromyelitis optica

“…34.5%) was consistent with the relative low seroprevalence of AQP4 Ab in Asian patients with NMO (Matsuoka et al, 2007;Wang et al, 2011). Whereas increased plasma levels of TNF-a, IFN-c, and IL-17 might suggest specificity for NMO, these cytokines are affected by many inflammatory diseases and are associated with the severity of inflammation.…”

“…Aquaporin 4 (AQP4) antibody (AQP4 Ab/NMO-IgG), an antibody against a water channel protein, has recently been described as a diagnostic marker for NMO (Lennon et al, 2004). However, its sensitivity varies between studies, being particularly low for Asian patients (e.g., $40% of patients with NMO show positivity for AQP4 Ab in Taiwan compared to $60-70% in Western countries) (Matsuoka et al, 2007;Wang et al, 2011). Therefore, AQP4 is not an optimal marker for NMO.…”

The Frequency of Anti-Aquaporin-4 Ig G Antibody in Neuromyelitis Optica and Its Spectrum Disorders at a Single Tertiary Referral Center in Malaysia

“…In their study, longitudinally extensive cord lesions were also seen more frequently in NMO than MS, that is, 72.4% versus 22.7%, P < 0.001 [ 15 ]. Studies from Thailand and Taiwan have demonstrated similar observations in their cohorts with LESCLs and seropositivity [ 16 , 17 ]. In fact, Wingerchuk et al found the presence of a longitudinally extensive cord lesion extending more than 3 vertebral segments to be the most reliable feature in the diagnosis of NMO [ 1 , 2 ].…”