Leucocyte migration inhibition factor (LIF) production by lymphocytes of normal children, newborns, and children with immune deficiency.

The reproducibility of a simplified, sensitive and rapid agarose-cell droplet assay for leucocyte migration inhibition factor (LIF) activity was studied. Removal of T cells with anti-T-cell serum eliminated LIF activity, indicating that in humans it is probably the T cell that produces LIF. Cord blood lymphocytes produce LIF, although spontaneous migration of leucocytes is less than in older children. The cause of this apparently does not reside in the PMN leucocytes. Studies of children with immunodeficiency suggest that the T-cell population in humans is heterogenous. B-cell deficiencies such as hypogammaglobulinaemia, have normal PPD and PHA induced LIF production, whilst some patients with ataxia-telangiectasia have defective PPD LIF activity, their PHA LIF activity being only minimally depressed. On the other hand, Down's syndrome patients with reduced blood T cells have remarkably deficient LIF activity to PHA and relatively good activity to PPD. Children receiving steroid therapy lose much of their ability to produce LIF to the specific antigen PPD, but not to the non-specific mitogen PHA.