Clinical outcomes in immunocompromised adults with COVID-19, based on anti-spike IgG serostatus and monoclonal antibody therapy: a retrospective cohort study in the Omicron period.

BACKGROUND: Immunocompromised adults may experience severe COVID-19 outcomes, necessitating a multifaceted treatment approach. Studies from the Delta period showed benefit from monoclonal antibody (mAb) therapy that was most pronounced among anti-spike IgG seronegative individuals. With widespread vaccination and shifting SARS-CoV-2 variants in the Omicron period, clinical predictors of anti-spike IgG seronegativity, and impacts on clinical outcomes, remain incompletely characterized. OBJECTIVES: We describe outcomes from a cohort of immunocompromised adults with COVID-19 stratified by anti-spike IgG serostatus and receipt of mAb therapy during the Omicron period to evaluate clinical impact. DESIGN: This was a retrospective study of immunocompromised adults with mild-moderate COVID-19 presenting between December 2021 and October 2022. METHODS: Charts were reviewed to assess anti-spike IgG serostatus, receipt of mAb therapy, and 28-day outcomes including conventional oxygen use, high-flow oxygen use, mechanical ventilation, and death. RESULTS: A total of 276 individuals were included, of whom 252 (91%) were partially or fully vaccinated, 190 (69%) were anti-spike IgG seropositive, and 225 (82%) received mAb therapy. A majority were solid organ transplant recipients (169, 61%), with anti-spike IgG seronegatively significantly associated with mycophenolate-based immunosuppression or comorbid chronic kidney disease. Conventional oxygen use among seropositive patients receiving mAb, seronegative patients receiving mAb, seropositive patients not receiving mAb, and seronegative patients not receiving mAb were 2/154 (1%), 5/71 (7%), 6/36 (17%), and 4/15 (27%), respectively. Across the cohort, high-flow oxygen use, mechanical ventilation, and death occurred in 6 (2%), 4 (3%), and 3 (1%) individuals, respectively. CONCLUSION: Clinical outcomes in a predominantly vaccinated, immunocompromised cohort with mild-moderate COVID-19 during the Omicron period appeared to vary with anti-spike IgG serostatus and receipt of mAb therapy. Observed trends would benefit from prospective studies during future iterations of COVID-19 therapeutics to inform treatment decisions for immunocompromised adults.