Improvement of impaired mitogen-induced interferon-gamma release of peripheral blood mononuclear cells derived from tumor patients by Factor AF2.

Factor AF2, a now standardized extract from liver and spleen of newborn lambs, showed myeloprotective capacity on platelet- and erythrocyte-count as well as on hemoglobinconcentration in patients undergoing aggressive chemotherapy. In addition, a possible influence on prolonged remission duration in patients with mammary carcinoma had been claimed. In this study, the effect of Factor AF2 on mitogen-induced interferon-gamma release by PBMC was tested in 23 healthy humans and in 23 tumor patients. All patients were prior to surgery and had not yet received radio- or chemotherapy at the time of examination. The interferon-gamma concentration of the supernatants was measured using an enzyme-linked immunosorbent assay (ELISA). The cells were stimulated with PHA at 7.5 micrograms/ml. In the reference group, interferon-gamma concentration rose to 26 units/ml and to 15.5 units/ml in the tumor patients. In the reference persons, an addition of Factor AF2 at concentrations from 10(1) micrograms/ml to 10(3) micrograms/ml resulted in a small non-significant decrease of interferon-gamma release. At 10(4) micrograms/ml, neither test group showed measurable interferon-gamma concentration. In the tumor patients, cocultivation with Factor AF2 until concentration of 10(2) micrograms/ml resulted in a dose-dependent increase of interferon-gamma release, where 20.5 units/ml interferon-gamma were reached. At 10(3) micrograms/ml, Factor AF2 showed no effect on interferon-gamma release compared with the stimulation with mitogen alone. Flow-cytometry analysis of CD3, CD4, CD8, CD16, CD19, CD56, and HLA-DR expression of the PBMC deriving either from reference persons or from patients revealed an almost identical distribution. A slight difference in CD16-positive and HLA-DR positive cells, respectively, was not significant.