Abstract
The treatment of human CMV infection in transplant recipients by intravenous or intramuscular administration with high doses of hyperimmune or normal Ig showed inconsistent results. In fact, all hyperimmune Ig preparations were produced from high anti-CMV Ab titer plasma selected either by ELISA, complement fixation, or indirect hemagglutination test. These tests may not investigate the neutralizing activity of antibodies (Ab). We, therefore compared the ELISA titers with the neutralizing Ab titers in various normal Ig preparations from plasma or placenta and for intramuscular or intravenous use. Hyperimmune plasmatic Igs were also included. All the preparations were tested at a 5% dilution. We report the following data: (1) There is a poor correlation between ELISA and neutralization test. (2) The Igs of placental origin have significantly higher ELISA anti-CMV Ab titers than plasmatic normal Igs. They show the same neutralizing activity. (3) When compared with the normal intravenous Ig, normal intramuscular Igs show significantly higher titers with both techniques (P less than .0001). (4) Normal intramuscular Igs from placenta offer similar ELISA Ab titers and similar or higher neutralizing activity than hyperimmune Igs purified from plasma. It would be worth using Igs with high neutralizing activity in CMV prophylaxis in order to correlate in vitro tests and in vivo protection. In this respect, normal intramuscular Igs from placenta might be challenged in a clinical trial.