Purification of severe acute respiratory syndrome hyperimmune globulins for intravenous injection from convalescent plasma

BACKGROUND: Severe acute respiratory syndrome (SARS) is a new infectious disease caused by the SARS virus. Current first-line treatments are experimental, and their effectiveness remains open to question. For more effective treatment and prevention of SARS, human SARS hyperimmune globulins for intravenous (IV) injection were purified in this study. STUDY DESIGN AND METHODS: A combination of cold ethanol precipitation and ion-exchange chromatography was used to process pooled SARS convalescent plasma samples. Virus inactivation and removal approaches were taken to ensure safety. RESULTS: The purified hyperimmune globulins were formulated as a 5 percent solution, with an antibody titer specifically against the SARS virus of 1:83, 1:1600, and 1:200, as determined by enzyme-linked immunosorbent assay, immunofluorescence assay, and neutralizing antibody test, respectively. The purity of the SARS hyperimmune globulins was 99.0 percent, and the monomer and dimer content was 100 percent. Other variables analyzed met the Chinese Requirements of Biologics for IV immune globulin. The SARS hyperimmune globulins prepared were subsequently approved for clinical evaluation by the Chinese National Institute for the Control of Pharmaceutical & Biological Products. CONCLUSION: IV-injectable, purified, and concentrated human SARS hyperimmune globulins were prepared from pooled convalescent plasma samples, which are ready to be further evaluated.