COVID-19 Convalescent Plasma Transfusion Shows Decreased Mortality for Immunocompromised Patients With COVID-19

A transfusion of plasma from a recently recovered individual who had COVID-19 was found to be associated with decreased mortality in immunocompromised patients with COVID-19, according to authors who published a study in JAMA Network Open. When administered within 72 hours of symptom onset, this antibody-based therapy has also been associated with decreased hospitalizations and disease progression for patients with severe COVID-19.

“Individuals who are immunocompromised are generally unable to mount strong antibody or inflammatory responses and often cannot clear SARS-CoV-2,” said study authors in the article.

“[However] antibody-based therapies may retain efficacy late into the course of disease [for patients who are immunocompromised].”

Early admission and sufficient dosage are imperative for the efficacy of antibody-based therapies. Fortunately, patients who treated in a later stage of disease progression showed mortality benefits.

One of the first therapies to combat COVID-19 at the start of the pandemic was a transfusion of COVID-19 convalescent plasma, which contained anti-SARS-CoV-2 neutralizing antibodies, into immunocompromised patients with severe COVID-19; these patients naturally have a greater risk of morbidly and mortality from COVID-19 than patients who are not immunocompromised.

“There has been a renewed interest in the clinical use of COVID-19 convalescent plasma, particularly for patients who are immunocompromised, who are not able to mount a sufficiently protective antibody response against the virus, and who have contraindications or adverse effects from small molecule antivirals,” study authors wrote.

Investigators conducted a systematic review and meta-analysis following Preferred Reporting Items for Systematic Reviews and Meta-analyses reporting guidelines of 8 clinical trials. The investigators aimed to assess the impact of COVID-19 convalescent plasma on mortality in patients with primary or secondary immunosuppression. Primary immunosuppression is defined as inheritable and secondary is related to cancers, autoimmune disorders, or transplants.

Of the 8 clinical trials assessed in the meta-analysis, 3 were randomized clinical trials and 5 were controlled studies. Based on their analysis of these trials, the investigators found that COVID-19 convalescent plasma was associated with reduced occurrence of mortality.

Specifically, individual-level data showed that mortality was reduced with convalescent plasma. Although 7 patients died in one of the studies, the comparative mortality was not significant compared to those who survived.

Investigators also found that COVID-19 convalescent plasma is superior to other classes of immunoglobulin G (IgG). Further, the efficacy of this treatment leads researchers to suggest that the treatment does not cause irreversible parenchymal damage.

Investigators are now conducting studies assessing the efficacy of COVID-19 convalescent plasma from vaccinated donors (called Vax-Plasma), which has higher neutralizing antibody efficacy against many COVID-19 variants.

The study includes limitations, the first being that the analyses contain uncontrolled case reports, which cannot provide definitive results. Additionally, the study was limited by access to patient-level data, preventing the use of a more complex statistical model. Finally, it was limited by a single outcome of all-cause mortality.

“Although these summary findings are encouraging for the use of therapeutic convalescent plasma in COVID-19 patients with primary or secondary immunosuppression, there remains a paucity of well-controlled, published data in these important patient populations,” study authors wrote. “The clinical use of COVID-19 convalescent plasma and Vax-Plasma in patients who are immunocompromised and have COVID-19 may warrant further investigation.”

Reference

Senefeld J, Franchini M, Mengoli C, et al. COVID-19 Convalescent Plasma for the Treatment of Immunocompromised Patients: A Systematic Review and Meta-analysis. JAMA Netw Open. 2023;6(1):e2250647. doi:10.1001/jamanetworkopen.2022.50647