ABSTRACT
Background: COVID-19-Convalescent Plasma (CCP) showed beneficial effects when given early in the treatment course or when it contains high-titre of neutralizing antibodies. Here we present a long-term follow up of patients of the multicentric national randomized CAPSID trial that investigated the effect of CCP in hospitalized COVID-19 patients. CCP donors were also included in the follow up and severed as a control group of patients with mild to moderate disease. Method(s): Patients and donors were invited to participate in the long-term follow up. Data on long-term overall survival (OS) were available for n=52 patients (control group: n=22, high titre CCP: n=16, low-titre CCP: n=14) and n=113 donors. Structured interview and a quality of life (QoL) assessment by questionnaires (FACIT fatigue, FACIT dyspnea and EQ-ED- 5DL) were performed. Visits took place online or on site. Laboratory tests included neutralizing antibody testing by PRNT and inflammation markers. Data are given as median with IQR. Medical events were assessed and graded according to CTCAE. For donors the median follow up time was 517 (483-553) days after the first plasmapheresis and for patients 395 (371-417) days after randomization. Result(s): Medical events during follow up were reported in 27% of donors and 16% of patients (p=0.164) with grade 3 or higher in 9% of donors and 22% of patients. More patients than donors reported a decrease in their socioeconomic status and reported more frequently about GI, pulmonal, pain symptoms or alopecia (p<0.02), but no difference in neurologic symptoms including anosmia was observed. Post COVID-Scale was worse in patients with a trend for better outcome in the CCP group (p=0.089). The trend for better OS in the CCP group became more pronounced during the long-term follow up (p=0.08) and OS remained significantly better in the high dose CCP group (p=0.01). All QoL scores showed a consistent trend towards better outcomes of the CCP group. Conclusion(s): To our knowledge, this is the first long-term follow up from a randomized trial of CCP. CCP-donors with mild to moderate COVID- 19 had a significant smaller long-term disease burden than patients with severe disease. The addition of CCP added to standard treatment in severe COVID-19 showed a trend to better OS and QoL. We had previously reported significant better outcomes in the high-titre CCP subgroup (until day 60). This was even more pronounced during the long-term follow up (> 1 year).