Frequency of comorbidities in Neuromyelitis Optica spectrum disorder

Comorbidity may influence clinical aspects of neuromyelitis optica spectrum disorder (NMOSD). We estimated the prevalence of comorbidities to assess their association with outcomes.

This retrospective study assessed records of NMOSD patients from 2008 to 2019, categorizing comorbidities into three groups: somatic, psychiatric and autoimmune. Severity of disease was evaluated by the Expanded Disability Status Scale, progression index (PI) and annualized relapse rate. The frequency of comorbidities was compared between anti-aquaporin 4 antibody (AQP4-IgG) seropositive and seronegative patients.

A total of 67 NMOSD patients were enrolled. Thirty-five (52.2%) patients reported at least one comorbidity. In total, 44 comorbidities were found, of which 24 occurred prior to NMOSD onset: 29 somatic, 13 psychiatric and 2 autoimmune entities. The most common comorbidities were anxiety disorders 7/67 (10.4%), followed by migraine 6/67 (8.9%) major depression disorder 6/67 (8.9%), iron deficiency anemia 8/54 (14.8%), and non-autoimmune hypothyroidism 4/67 (6.0%). Psychiatric comorbidities associated with PI in unadjusted (OR=0.538, 95% CI=0.141, 0.935, P=0.009) and adjusted models (OR=0.386, 95% CI=0.022, 0.751, P=0.038). A significantly higher frequency of psychiatric comorbidities was observed in the AQP4-IgG positive patients (P=0.031).

Half of the patients had comorbidities, suggesting screening for comorbidity as part of NMOSD care. The psychiatric comorbidities had impact on clinical outcome.