Relapse And Non-relapse Hospitalizations in Neuromyelitis Optica Spectrum Disorders (NMOSD)
Philippe-Antoine Bilodeau1, Sathya Narasimhan2, Danielle Kei Pua2, Kathryn Holroyd3, Farrah Mateen1, Michael Levy1, Shamik Bhattacharyya2
1Massachusetts General Hospital/Harvard Medical School, 2Brigham and Women's Hospital - HMS, 3Yale New Haven Hospital
Objective:
To determine the characteristics of hospitalizations in a cohort of patients with NMOSD.
Background:
Hospitalization in NMOSD may result from relapses, infectious complications, symptom management or other medical complications.
Design/Methods:
A retrospective analysis of patients diagnosed with NMOSD according to the 2015 criteria at Mass General Brigham hospital system from 2005-2021. Data on demographics, disease course, treatments, and hospitalizations were collected.
Results:
127 patients were included; 82.9% were AQP4 seropositive and 81.1% were female. The most common phenotypes at presentation were myelitis (47.9%) and optic neuritis (41.7%). Median follow-up time from diagnosis was 5 years (IQR 2-8). Median length of stay for relapse hospitalizations was 6 days (IQR 4-11). 64.2% of patients received corticosteroids and 19.8% underwent plasma exchange. Relapse hospitalizations had secondary nosocomial complications in 46% of which the most common cause was infection (38%). In univariate negative binomial regression analysis, one-unit increase in mRS score and presence of infections were associated with a 26% (IRR=1.26, 95% CI = [1.12,1.42], p < 0.001) and 75% increase in expected length of stay (IRR=1.75, 95% CI = [1.36, 2.26], p < 0.001). Use of mycophenolate mofetil (MMF) was associated with 4-fold increase in odds of infectious complication during admission (OR=4.05, 95% CI 1.36-12.05, p=0.01). Adjusting for acute treatments and admission mRS, optic neuritis was associated with 39% reduction in expected length of stay (IRR=0.61, 95% CI = [0.48, 0.78], p<0.001). Median length of stay for non-relapse hospitalizations was 5 days (IQR 3-11). The most common reason for non-relapse hospitalization was infection (46%). There were 10 deaths in the cohort; one was NMOSD-related.
Conclusions:
NMOSD often necessitates extended hospitalizations for relapses and non-relapses, with infections being frequent complication and a common non-relapse admission cause. Admission mRS and infections predict longer relapse hospitalizations, while MMF usage is associated with increased infection odds during admission.