On April 6, 2020, the Proceedings of the National Academy of Sciences (US) reported a 10-person study using convalescent plasma (CP) to treat severe COVID-19 patients. Larger randomized trials are needed, but the results appear promising: one dose (200 mL) of CP was well-tolerated with 3 cases discharged and 7 significantly improved and ready for discharge. The controls (no plasma treatment) showed 3 deaths, 6 stabilized, and 1 improved.
The primary purpose of the study was to evaluate the safety of convalescent plasma (CP). Secondary endpoints were improvement of clinical symptoms and laboratory parameters within 3 days after CP transfusion.
Median CP treatment time for the patients was 16.5 days from the start of illness. Median patient age was 52.5 years, and none of the patients had direct exposure to Huanan Wholesale Seafood Market. Seven of the 10 patients presented with fever, cough, and shortness of breath, and before CP treatment 8 of the patients were either mechanically ventilated or received oxygen.
All symptoms in the 10 patients, especially fever, cough, shortness of breath, and chest pain, disappeared or largely improved within 1 day to 3 days upon CP transfusion. These results suggest that CP treatment may alleviate the immune system overreaction and related inflammation characteristic of the severe pneumonia associated with COVID-19.
The optimal dose of CP and its timing should be further investigated in well-controlled trials, as well as the clinical benefit of CP. The researchers noted that all 10 patients also received drugs including antivirals, antibiotics, and glucocorticoids, and the potential of these drugs to contribute to recovery is not known. However, the small study shows promising results for severe COVID-19 cases based on all 10 patients achieving primary and secondary outcomes from treatment with convalescent plasma.
The paper was submitted to PNAS by one of the researchers and went through open peer review.
Featured image credit: Wuhan Medical Treatment Center