NATURAL AND THERAPY-INDUCED ANTI-GM-CSF AND ANTI-G-CSF ANTIBODIES IN HUMAN SERUM

Serum samples were obtained from patients with lymphoid and plasma cel l malignancies who received after chemotherapy human recombinant GM-CS F or G-CSF. Sera from some patients revealed the presence of anti-cyto kine antibodies, particularly after repetitive cytokine injections. An tibody Fab binding in a saturable manner by ELISA and Western immune-b lotting confirmed antibody specificity. Anti-cytokine antibodies were detected before the exogenous cytokine injections in some patients, bu t increasing antibody levels were found after one or subsequent treatm ents. Low levels of anti-GM-CSF and anti-G-CSF antibodies were also de tected in a relatively large proportion (about 10-30%) of normal sera from different adult healthy volunteers who had never been treated bef ore with exologous cytokines as well as from cord blood. EBV-immortali zed cord blood derived B-cell cultures were also found to produce anti GM-CSF and/or anti-G-CSF antibodies with high frequency.