Convalescent plasma for persistent symptomatic COVID-19 infection in immune-suppressed patients - a case series.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection progresses from an initial direct viral cell injury to an immune-mediated response. In most cases, the immune response results in viral clearance and recovery after a mild disease. Severe infections seem to result mainly from uncontrolled immune-mediated damage. Accordingly, initial treatment involves an antiviral strategy, while late severe infection is treated with anti-inflammatory medication. Immunocompromised patients have reduced vaccine efficacy and reduced ability to mount an appropriate immune response to SARS-CoV-2 infection, making them extremely susceptible to prolonged and severe infections. For these patients, standard treatment protocols need further investigation. In this retrospective case series, we investigated the effect of convalescent plasma and late antiviral treatment in twenty-three immunosuppressed patients, mostly pre-vaccinated (91%), presenting with symptomatic prolonged SARS-CoV-2 infection. All patients received initial antiviral treatment at the time of the first confirmed SARS-CoV-2 infection but continued to have symptoms. Convalescent plasma in addition to other treatments, including antivirals, resulted in significant improvement in 22 patients. Statistically significant improvement was detected in oxygen supplementation requirement (69.5% vs. 48%, p = 0.025), fever (61% ± 0.96 vs. 4% ± 0.42, p = 0.001), and C-reactive protein (9.6 ± 7.64 vs. 5.05 ± 5.05, p = 0.007). Interestingly, increases in white blood cell counts were found to be good predictors of improvement in this population. Our data suggest that CCP and antiviral treatment in the later phases of coronavirus disease 2019 may be necessary for immunosuppressed individuals with prolonged disease.