Effects of serum and plasma from hemodialysis patients on the lymphoproliferative response

The effect of serum and plasma from hemodialysis patients on the immune response was investigated in vitro using phytohemagglutinin(PHA)-, concanavalin A(Con A)-, and staphage lysate(SPL)-induced and spontaneous blastogenesis of peripheral lymphocytes from a healthy person. An immunosuppressive substance(s) was found to exist in these samples and markedly increased in activity after hemodialysis. This substances(s) was heat-labile (56 degrees C, 30 min) and had a molecular weight of 50,000 daltons or more. It was not related to heparin. The appearance of this substance(s) was not influenced by the patients' sex or age or by the duration of hemodialysis.