[In vitro production of specific antibodies: preliminary results]

In vitro production of specific antibodies or IVPA is a technique that involves isolating mononuclear cells from blood, placing them in culture, and detecting antibodies in the culture supernatant. The presence of antibodies confirms active production by B lymphocytes and is proof of ongoing infection. To validate this technique for routine laboratory use, we tested 16 subjects: 11 for toxoplasmosis and cytomegalovirus and 5 for viral hepatitis type A or B. The results obtained using IVPA were compared with those obtained using conventional serologic methods. IVPA documented IgM for cytomegalovirus in the only subject in whom serology showed IgM for that virus. The test was also positive in 2 subjects undergoing vaccination for viral hepatitis type B and suffering from acute viral hepatitis type A. These concordant results demonstrate that IVPA is a valuable adjuvant technique for diagnosis of ongoing infection especially insofar as it avoids the need for antibody kinetic studies or isolation of the virus. It also provides a simpler and less expensive alternative to gene amplification and cell culture.