Background and objectives: We previously found that interferon-gamma (IFN-gamma) antibodies in intravenous immunoglobulins (IVIG) can block not only IFN-gamma production and tumor necrosis factor-alpha secretion, but also T-cell proliferation. Since the presence of IFN-gamma antibodies has been attributed to previous viral infection, we hypothesized that the viral status of the plasma donors used for IVIG pools might be a decisive factor in controlling the immunosuppressive capacity of IVIG.
Materials and methods: We tested three different pooled, human IVIG preparations for the presence of IFN-gamma antibodies by ELISA.
Results: Comparison of the immunomodulatory activity of polyvalent IVIG with that of specific CMV and HBs IVIG showed that the latter-had higher levels of IFN-gamma antibodies and an increased capacity to block mixed lymphocyte reaction and cytokine production.
Conclusion: We propose that these in vitro assays constitute a basis for the selection of plasma intended for manufacturing IVIG aimed at immunosuppression in the transplant setting.