Clinical and Economic Implications of Immunoglobulin Use Under Restrictive Conditions in Adult Patients With Neurological Diseases and Immunodeficiencies in Spain

BACKGROUND/OBJECTIVES: Immunoglobulin (Ig) therapy is the first-line treatment and often the single option for a substantial number of diseases. Still, Ig supply and use have experienced restrictions, aggravated during the COVID-19 pandemic. This study assessed the clinical and economic implications of Ig use under restrictive conditions in neurological diseases and immunodeficiencies in Spain. METHODS: Hospitalization cases in neurological disorders and immunodeficiencies in which Ig is the main therapeutic option, identified by ICD-10 codes, were retrieved from the Spanish Minimum Basic Data Set for 2019 and 2022. Comorbidities and outcomes were analyzed along with hospitalization rates and characteristics, like the length of stay (LoS) and costs, among others. Therapeutic plasma exchange (TPE) use was evaluated as the alternative treatment of choice in the conditions analyzed. RESULTS: In 2022 compared to 2019, hospitalizations due to relapses remained stable in patients with neurological conditions. Comorbidity and complications increased significantly in this group, as well as LoS, mofrtality (p < 0.05 for all), and TPE rates (p = 0.003). These changes were not identified for immunodeficiencies, which only experienced a decrease in hospitalization rates (p < 0.001). Hospital costs increased in both groups (7.97% in neurological conditions and 2.41% in immunodeficiencies). CONCLUSIONS: In a period in which access to Ig may have been limited, neurological patients, but not patients with immunodeficiencies, show an increase in LoS and mortality, as well as an increased TPE. These results suggest that modifying the management strategy of patients with neurological disorders requiring Ig due to restrictive conditions could have negatively impacted their clinical outcomes.