Franchini, Massimo

ABSTRACT Anti‐Spike monoclonal antibodies (mAbs) progressively lost efficacy during the COVID‐19 pandemic due to the emergence and predominance of resistant SARS‐CoV‐2 variants. By contrast, high‐titre COVID‐19 convalescent plasma (CCP) collected from vaccinated donors recently recovered from infection provides a polyclonal source of antibodies that remains effective in clearing SARS‐CoV‐2 in immunosuppressed patients, unable to mount an adequate immune response against the virus. We conducted a systematic review and individual participant data meta‐analysis to examine the effect of CCP in immunocompromised patients persistently positive for SARS‐CoV‐2 viraemia following mAb therapy, and to evaluate possible biological factors associated with a favourable outcome. Electronic databases were searched for studies published from January 2020 to January 2026. All studies including eligible cases were considered in the systematic review. Unpublished cases were also collected from investigators of the selected studies. The protocol was registered at PROSPERO (CRD420251142891). Forty‐seven cases (30 cases from 12 published studies and 17 unpublished cases) were included. In 33 out of 47 patients (70.2%) with a mAb‐resistant infection, SARS‐CoV‐2 clearance occurred following CCP transfusion, with a mean of 2.7 CCP units administered. In logistic regression, total CCP volume transfused was positively associated with SARS‐CoV‐2 clearance. In conclusion, CCP transfusion was associated with SARS‐CoV‐2 clearance in persistently positive immunocompromised patients following failure of anti‐Spike mAb therapy.

Plasma collected from people recovered from COVID-19 (COVID-19 convalescent plasma, CCP) was the first antibody-based therapy employed to fight the pandemic. CCP was, however, often employed in combination with other drugs, such as the antiviral remdesivir and glucocorticoids. The possible effect of such interaction has never been investigated systematically. To assess the safety and efficacy of CCP combined with other agents for treatment of patients hospitalized for COVID-19, a systematic literature search using appropriate Medical Subject Heading (MeSH) terms was performed through PubMed, EMBASE, Cochrane central, medRxiv and bioRxiv. The main outcomes considered were mortality and safety of CCP combined with other treatments versus CCP alone. This review was carried out in accordance with Cochrane methodology including risk of bias assessment and grading of the quality of evidence. Measure of treatment effect was the risk ratio (RR) together with 95% confidence intervals (CIs). A total of 11 studies (8 randomized controlled trials [RCTs] and 3 observational) were included in the systematic review, 4 studies with CCP combined with remdesivir and 6 studies with CCP combined with corticosteroids, all involving hospitalized patients. One RCT reported information on both remdesivir and steroids use with CCP. The use of CCP combined with remdesivir was associated with a significantly reduced risk of death (RR 0.74; 95% CI 0.56–0.97; p = 0.03; moderate certainty of evidence), while the use of steroids with CCP did not modify the mortality risk (RR 0.72; 95% CI 0.34–1.51; p = 0.38; very low certainty of evidence). Not enough safety data were retrieved form the systematic literature analysis. The current evidence from the literature suggests a potential beneficial effect on mortality of combined CCP plus remdesivir compared to CCP alone in hospitalized COVID-19 patients. No significant clinical interaction was found between CCP and steroids.

Since December 2019, SARS-CoV-2 is ravaging the globe, currently accounting for over 660 million infected people and more than 6 [...]

AbstractCOVID‐19 convalescent plasma (CCP) was among the few frontline therapies used to treat COVID‐19. After large randomized controlled trials (RCTs) relying on late use in hospitalized patients and/or low antibody titres failed to meet their predefined primary endpoint, the infectious disease community reduced usage of CCP in favour of monoclonal antibodies. Consequently, there are CCP stocks at most transfusion centres worldwide, although scattered usage continues. Further, better designed RCTs are also being launched. The urgent question here is: should we use CCP units collected months before given the largely changed viral variant landscape? We review here in vitro evidence that discourages usage of such CCP units against Delta and other variants of concern. CCP collections should be continued in order to update the armamentarium of therapeutics against vaccine breakthrough infections or in unvaccinated patients and is especially relevant in next‐generation RCTs.

COVID-19 convalescent plasma (CCP) is currently under investigation for both treatment and post-exposure prophylaxis. The active component of CCP mediating improved outcome is commonly reported as specific antibodies, particularly neutralizing antibodies, with clinical efficacy characterized according to the level or antibody affinity. In this review, we highlight the potential role of additional factors in CCP that can be either beneficial (e.g., AT-III, alpha-1 AT, ACE2+ extracellular vesicles) or detrimental (e.g., anti-ADAMTS13, anti-MDA5 or anti-interferon autoantibodies, pro-coagulant extracellular vesicles). Variations in these factors in CCP may contribute to varied outcomes in patients with COVID-19 and undergoing CCP therapy. We advise careful, retrospective investigation of such co-factors in randomized clinical trials that use fresh frozen plasma in control arms. Nevertheless, it might be difficult to establish a causal link between these components and outcome, given that CCP is generally safe and neutralizing antibody effects may predominate.