(HealthDay News) — One dose of convalescent plasma (CP) therapy is well tolerated and can potentially improve clinical symptoms in severe cases with coronavirus disease 2019 (COVID-19), according to a study published online in the Proceedings of the National Academy of Sciences.
Kai Duan, from the China National Biotec Group Company Limited in Beijing, and colleagues prospectively enrolled 10 patients with severe COVID-19 confirmed by real-time viral RNA tests. Patients received a transfusion of one dose of CP derived from recently recovered donors with neutralizing antibody titers above 1:640; patients also received maximal supportive care and antiviral agents. From onset of illness to CP transfusion, there was a median time of 16.5 days.
The researchers found that the level of neutralizing antibody increased rapidly up to 1:640 in 5 cases after CP transfusion; in 4 other cases, the high level was maintained (1:640). Significant improvement was seen in clinical symptoms, with an increase of oxyhemoglobin saturation within 3 days. Compared with pretransfusion, several parameters tended to improve, including increased lymphocyte counts and reduction in C-reactive protein. Varying degrees of absorption of lung lesions were seen within 7 days on radiological examinations. In 7 of the patients who had previous viremia, the viral load was undetectable after transfusion.
“The optimal dose and treatment time point, as well as the definite clinical benefits of CP therapy, need to be further investigated in randomized clinical studies,” the authors write.