Clinicopathological Features of Pakistani Patients with Anti Aquaporin-4 (Aqp-4) Antibody Positive Neuromyelitis Optica Spectrum Disorder (NMOSD): A Comparison with Local, Regional and International StudiesOPTICA SPECTRUM DISORDER(NMOSD)-A COMPARISON

Objective: To characterize clinicopathological characteristics of patients with anti AQP-4 antibody positive Neuromyelitis Optica Spectrum Disorder in local population in order to facilitate clinicians in timely diagnosis and treatment of this rare debilitating illness. Study Design: Cross-sectional study. Place and Duration of Study: Department of Immunology, Armed Forces Institute of Pathology, Rawalpindi Pakistan, from Jun 2021 to Dec 2022. Methodology: The study included 369 individuals presenting at Armed Forces Institute of Pathology for serum anti AQP-4 antibody testing by indirect immunofluorescence. Commercial Anti Aquaporin-4 Indirect Immunofluorescence Test Slides along with control serum (EUROIMMUN Medizinische Labordiagnostika AG, Lubeck, Germany) were used and immune-fluorescence was observed using immunofluorescent microscope BA-310. Results: Out of 369 patients who were tested for Anti Aquaporin-4 antibody, 168(45.5%) were females and 201(54.5%) were males. Total 9(2.43%) patients tested positive including 5(55.5%) females and 4(44.4%) males (p=0.947). Most prevalent core clinical characteristics among patients with Neuromyelitis Optica Spectrum Disorder were optic neuritis 7(77.8%), acute myelitis 7(77.8%) and area postrema syndrome 6(66.6%). Common presenting core clinical characteristics were area postrema syndrome 4(44.4%) and acute myelitis 4(44.4%). Average diagnostic delay in our study was 2.7±3.2 years. Conclusion: By keeping high index of suspicion for presenting core clinical characteristics (area postrema syndrome and acute myelitis) clinicians may be able to diagnose and treat this rare disease timely hence decrease average diagnostic delay and prevent associated morbidity and mortality.