Cytokine activity after allogeneic bone marrow transplantation. IV. Production of mRNA for IL-3 and GM-CSF by mitogen-stimulated circulating mononuclear cells.

The ability of circulating mononuclear cells from recipients of HLA identical sibling marrow transplants to generate messenger (m) RNA for the haemopoietic growth factors interleukin-3 (IL-3) and granulocyte-macrophage colony-stimulating factor (GM-CSF) upon mitogen stimulation was investigated. The amount of IL-3 mRNA per ml of blood and IL-3 mRNA per 10(7) mononuclear cells as well as the amount of GM-CSF mRNA per ml of blood was significantly lower in transplant recipients than in normal volunteers. Lower values for mRNA expression for both IL-3 and GM-CSF were associated with the use of immunosuppressive therapy post transplant. No correlation was found between the expression of message for either cytokine, or the presence or absence of acute graft-versus-host disease at the time of testing. While there was no correlation between the quantity of GM-CSF message produced and time elapsed post transplant, IL-3 message expression increased slightly with increasing time post transplant. These defects of haemopoietic regulators constitute another parameter of impaired cellular immunity occurring after allogeneic marrow transplantation.