The activity of the leucocyte inhibitory factor (LIF) stimulated with Concanavalin A was examined in chronic uraemic, haemodialysed patients. It was found that the LIF activity decreased in chronic uraemic patients as compared with the normal controls.
The absolute T lymphocyte count and active E rosette formation also decreased. In
in vitro experiments the authors have also examined the inhibitory effect of the socalled
middle-sized molecule
(MSM) on uraemic materials separated from the serum and the haemofiltrate. They observed that the materials with a molecular weight of 1000–1500 isolated both from the serum and the haemofiltrate significantly inhibited the Con A stimulated LIF production of normal lymphocytes and decreased the ratio of the active E rosette-forming T lymphocytes.
On the basis of their exeeriments the MSM uraemic materials are considered responsible for the decreased immune reactivity of uraemic patients. These uraemic toxins can be dialysed.