Therapeutic plasma exchange decreases plasma anti‐SARS‐CoV‐2 spike IgG without increasing the proximate incidence of COVID‐19

Abstract

AbstractBackgroundTherapeutic plasma exchange (TPE) removes both pathologic and protective immunoglobulins (Ig). SARS‐CoV‐2 immunity is partially mediated by anti‐SARS‐CoV‐2 spike antibodies (SAb), which impair viral host‐cell invasion. Nonetheless, the systematic effect of TPE on SAb concentration and SARS‐CoV‐2 immunity is unknown.MethodsPaired plasma waste specimens from the first (first‐TPE) and last (last‐TPE) TPE treatment were collected from 9 patients between July 21, 2021 and March 1, 2022. The effects of TPE on Ig levels were assessed by quantitatively comparing the SAb, total IgG, and total IgM levels first‐/last‐TPE treatment. Complementary qualitative assessment for these changes was achieved via protein electrophoresis (PEP) and immunofixation (IFE). A retrospective review was performed to investigate the incidence of new SARS‐CoV‐2 infections following TPE v. other treatment at the same outpatient apheresis/infusion center during the same time frame.ResultsMedian SAb levels between the first‐ and last‐TPE waste specimens decreased significantly from 424.6 AU/mL to 17.0 AU/mL (P = 0.004). Concordantly, PEP and IFE analysis demonstrated broad Ig decreases. Cumulative incidence of subsequent COVID‐19 diagnosis at 30, 90, and 180 days post‐procedure did not differ between the TPE v. other treatment groups (n = 709 total patients).ConclusionsTPE significantly reduced SAb levels, a marker of SARS‐CoV‐2 immunity, but did not appear to provoke increased incidence of COVID‐19 infections. Further investigation of the kinetics of TPE‐mediated SAb decrease and post‐TPE recovery are warranted.