Aim: The aim of this study was to verify the application of Overall Disability Sum Score (ODSS) for standardized clinical assessment of neurological involvement in patients with eosinophilic granulomatosis with polyangiitis (EGPA) and its correlation with treatment response and long-term outcomes.
Methods: Consecutive EGPA patients referred to our tertiary vasculitis center were retrospectively evaluated. Patients' neurological damage and disability were systematically assessed with Vasculitis Damage Index and ODSS.
Results: Fifty EGPA patients were included in the study with a median follow-up of 75 months (9-180 months). Twenty-five (50%) developed peripheral neuropathy, 17 (68%) presented mononeuritis multiplex, whereas 8 (32%) had symmetric polyneuropathy. Patients with neurological involvement were older (56.3 ± 13.4 vs. 44.4 ± 12.1 years, P < 0.0009), more frequently antineutrophil cytoplasmic antibody positive (48% vs. 16%, P = 0.015), and were more likely to have renal involvement (24% vs. 0%, P = 0.022). An early clinical response to therapy was observed within 6 months of treatment, resulting in a significant decrease in ODSS, which fell from the baseline value of 4.2 ± 2.4 to 2.9 ± 1.5 (P = 0.0001), whereas only a slow decreasing pattern was noted over the long-term period. However, all subjects developed neurological impairment and disability despite remission from active vasculitis. Patients with ODSS of greater than 3 at baseline (n = 13 [52%]) retained a higher score at the last examination (P < 0.001), predicting a low therapeutic response. Furthermore, ODSS of greater than 3 was found associated with more neurological relapses (53.8% vs. 0%, P = 0.027).
Conclusion: Overall Disability Sum Score could be a rapid, simple, reliable instrument to evaluate the severity of disability and nerve damage due to neurological involvement caused by vasculitis and to predict, at presentation, improvement and risk of neurological worsening.