[Human monoclonal anti-cytomegalovirus antibodies]

Specific human monoclonal anti-CMV antibodies have been isolated and characterized. The first patient had a chronic T cell lymphocytic leukaemia and a subclinical CMV infection developed at the same time as a monoclonal peak of kappa IgG3. The purified F (ab')2 fragment of the IgG3 had an intense anti-CMV activity. A second monoclonal antibody, also a kappa IgG3, was isolated in a non-immunodepressed patient with a primary CMV infection (chronic pyrexia and hepatitis). The immunotransfer showed that the anti-CMV IgM and IgG of the patient's serum reacted particularly with the p51 protein of virus capsid. The monoclonal IgG3 was specific for the same p51. The third monoclonal anti-CMV Ig studied was synthesized in vitro by the B lymphocytes of a renal transplant patient immortalized by the Epstein-Barr virus. This kappa IgM produced continuously reacted strongly with the nucleus of the cells infected by the CMV. Human monoclonal anti-CMV antibodies could be used for the early detection of viral antigens by immunofluorescence and might also be used to treat severe cases of CMV infection.