TRIM21 and synovial sarcoma: NMOSD incidence is 0.05 per 100,000 among populations in Abu Dhabi.[9] A retrospective study revealed that aquaporin 4 (AQP4)-positive patients are closely associated with nonorgan-specific autoantibodies, including anti-SSA, anti-SSB, anti-ANA, and anti-dsDNA antibodies.[10] Previous studies have shown that SS and SLE are related to NMOSD in systemic ADs.[7] The existence of SS in patients with NMOSD has been estimated to be 2% to 30%.[11] The majority of AQP4-IgG seropositive patients (NMOSD-related biomarker) are associated with a high intensity of inflammatory disease activity.