Research Article: Comparison of clinical and laboratory characteristics of neuromyelitis optica spectrum disorder with or without anti-connective tissue antibodies: an 18-month cohort follow-up
Abstract:
This study aimed to explore the significance of anti-connective tissue antibodies in the clinical diagnosis and evaluation of neuromyelitis optica spectrum disorder (NMOSD).
Demographic and clinical data from 205 patients with aquaporin-4 immunoglobulin G (AQP4-IgG)-positive NMOSD were collected. Variables included sex, age, clinical symptoms/signs, connective tissue antibody status, inflammatory markers, cerebrospinal fluid (CSF) cell counts/oligoclonal band status, spinal cord lesion location/length, Expanded Disability Status Scale scores at onset and first relapse (18-month follow-up), and time to first relapse.
Among the 205 patients, 108 (52.7%) were positive for anti-connective tissue antibodies (CTD abs+). Compared with anti-connective tissue antibodies (CTD abs?) patients, the CTD abs+ group had higher lymphocyte counts (1.82 ± 0.14 vs. 1.73 ± 0.07, p < 0.01), higher monocyte-to-lymphocyte ratios [0.27 (0.2) vs. 0.24 (0.16), p = 0.037], and higher CSF white blood cell counts [10 (22) vs. 6 (18)/10 6 /L, p = 0.035]. They also showed a higher rate of oligoclonal band positivity (27.78% vs. 10.31%, p = 0.002), a higher proportion of patients with an increased 24-hour intrathecal synthesis rate (54.6% vs. 40.2%, p = 0.039), and higher CSF immunoglobulin levels [5.755 (6.37) vs. 4.15 (3.53) mg/dL, p < 0.001] at initial onset. No significant differences were observed between the CTD abs+ and CTD abs? groups in the distribution of lesions or the length of affected spinal cord vertebral segments at initial onset. However, patients in the CTD abs+ group had higher Expanded Disability Status Scale scores at first relapse and a higher annualized relapse rate over the 18-month follow-up period( p < 0.05for both).
In summary, among AQP4-IgG-positive patients with NMOSD, CTD abs+ was associated with higher lymphocyte counts, a higher MLR, higher CSF white blood cell counts, higher CSF immunoglobulin levels, a higher 24-hour intrathecal IgG synthesis rate, and higher OCB positivity. CTD abs positivity may therefore indicate a more severe inflammatory profile; however, it does not appear to predict earlier relapse, but does appear to predict a higher annualized relapse rate.
Introduction:
Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune disease of the central nervous system (CNS) that can lead to a range of clinical syndromes involving the optic nerve and spinal cord ( 1 , 2 ). It is primarily caused by pathogenic autoantibodies that specifically target aquaporin-4 (AQP4) proteins located on the foot processes of astrocytes ( 3 ). AQP4-IgG autoantibodies exhibit high specificity and affinity for AQP4 antigenic sites, triggering a complement cascade and exacerbating inflammatory…
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