Comparison of intravenous immunoglobulin and plasma exchange in hospital-acquired infections of autoimmune encephalitis in a tertiary care center

Abstract Background The prevailing approach for the acute-phase treatment of autoimmune encephalitis (AIE) is currently the administration of intravenous immunoglobulin (IVIG) or plasma exchange (PLEX), in conjunction with high-dose corticosteroids. Despite this, there is still no definitive evidence on the risks and benefits of IVIG vs. PLEX in terms of treatment-related complications. Objectives The primary objective of this study was to determine the differences in the cumulative incidence of hospital-acquired infections (HAIs) in patients diagnosed with AIE, who received either IVIG or PLEX. The secondary objectives were to explore the differences in the duration of hospitalization and levels of disability. Methods Patients who were hospitalized at the King Chulalongkorn Memorial Hospital, Thailand, due to AIE, were aged ≥15 years, and had received either IVIG or PLEX during their hospitalization from January 2015 to December 2020 were included in the study. The modified Rankin scale (mRS) was utilized to evaluate the degree of disability at admission and discharge. Results Among the 44 patients included in the study, 10 (22.7%) received PLEX and 34 (77.3%) received IVIG. Those who received IVIG were significantly less likely to have HAIs (14.7% vs. 50.0%, P = 0.03) and had a significantly shorter duration of hospitalization (median [IQR] 12.0 [6.0 – 23.0] vs. 25.0 [21.0 – 49.0] d, P = 0.01) compared to those who received PLEX. Primary septicemia was the most commonly observed cause of infection in both groups. There were no significant differences in mRS at discharge, changes in mRS between admission and discharge, and the total direct cost of hospitalization between the two groups. Conclusions The utilization of IVIG is associated with a diminished occurrence of nosocomial infections, leading to shorter hospitalization and potential cost benefits. Our findings propose that IVIG may represent a more beneficial therapeutic alternative for AIE patients compared with PLEX.