Comparison of the neutralizing and ELISA antibody titres to human cytomegalovirus (HCMV) in human sera and in gamma globulin preparations.

Administration of anti-cytomegalovirus gamma globulin has been reported to prevent acute human cytomegalovirus (HCMV) infection in immunocompromised patients. Most likely the gamma globulin acts by its neutralizing activity. However, the antibody titer to HCMV in hyperimmune gamma globulin is usually detected by an enzyme immunoassay (ELISA). We, therefore, compared the ELISA titres with the neutralizing antibody titres in the sera of blood donors and in hyperimmune gamma globulins. A poor correlation between both titres was found. Gamma globulin preparations with identical ELISA titres clearly differed in the neutralizing titre. If neutralization is the important mechanism by which the hyperimmune gamma globulins work, our results would favour a routine testing of the neutralizing antibody titre in HCMV hyperimmune gamma globulins.