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Effectiveness of convalescent plasma therapy in severe COVID-19 patients

Our take —

In a small case series from China, patients received convalescent plasma and showed improvement in clinical symptoms, a reduction in markers of inflammation, a rise in neutralizing antibodies, and reduction in viral load. It is entirely possible all of these findings would have happened regardless of the administration of convalescent plasma. Clinical trial data is needed.

Study design

Case Series

Study population and setting

This was a pilot study in three participating hospitals in China to explore the feasibility of convalescent plasma treatment in 10 severe COVID-19 cases. The study sample consisted of 6 males and 4 females with a median age of 52.5 years (IQR, 45.0 to 59.5 ), and the median time from onset of symptoms to transfusion of 16.5 days (IQR, 11.0 to 19.3 ). Nine patients received arbidol monotherapy or combination therapy with remdesivir, or ribavirin, or peramivir, while one patient received ribavirin monotherapy; 6 received methylprednisolone.

Summary of Main Findings

The authors describe the clinical courses of the patients after receiving convalescent plasma (CP). They report that symptoms in the 10 patients had either disappeared or largely improved within 1-3 days post of transfusion. They also note improvement in lymphopenia ((median: 0.65 × 109 per L vs. 0.76 × 109 per L), as well as laboratory parameters of inflammation, such as C-reactive protein (CRP) (median: 55.98 mg/L vs. 18.13 mg/L), alanine aminotransferase (median: 42.00 U/L vs. 34.30 U/L), and aspartate aminotransferase (median: 38.10 U/L vs. 30.30 U/L). They also noted the neutralizing antibody titers of 5 patients increased after transfusion, and that SARS-CoV-2 RNA was decreased to an undetectable level in three patients on day 2, three patients on day 3, and one patient on day 6 after CP therapy.

Study Strengths

This is one of the first case series to report the use of convalescent plasma in patients with COVID-19.


This is a small case series with no comparator, limiting interpretation of convalescent plasma’s impact on clinical course. Additionally, data on inflammatory markers may be confounded by methylprednisolone administration.

Value added

This article is simply a description of the use of convalescent plasma and should not change clinical practice; rather it adds to the existing small body of literature on the use of convalescent plasma in COVID-19.