COVID-19 patients treated with convalescent plasma.

Background: In Norway, treatment with COVID-19 convalescent plasma has been given through the NORPLASMA project. The treatment was initially offered to critically ill patients after an individual assessment, but from December 2020, the indication was limited to critically ill, immunocompromised patients. In this article we describe clinical characteristics, comorbidity and mortality in patients who received convalescent plasma in these two periods.
Material and Method: From 22 April 2020 to 30 March 2022, a total of 79 patients were included in the observational studies NORPLASMA MONITOR and the Norwegian SARS-CoV-2 study. The patients had received a total of 193 units of convalescent plasma at 15 Norwegian hospitals/nursing homes; 62 in South-Eastern Norway Regional Health Authority, 8 in Western Norway Regional Health Authority and 9 in Central Norway Regional Health Authority. Information on immune status, comorbidity and course of infection was retrieved from the patient records after informed written consent was obtained.
Results: Of 79 patients with a median age of 65 years (interquartile range 51-⁠73) who were treated with convalescent plasma, 31 (39 %) died during hospitalisation. A total of 59 patients were immunocompromised, and of these, 20 died in hospital compared to 11 of 20 who were assumed to be immunocompetent. Median number of comorbidities was 2 (interquartile range 1-4). The patients received a median of two plasma units (min.-max. 1-21). Two of the patients developed mild allergic skin reactions.
Interpretation: Convalescent plasma was well tolerated by patients with COVID-19. Immunocompromised patients may have benefitted from the treatment, with lower mortality than for those assumed to be immunocompetent.