In vitro Characterization of Immunological Responsiveness of Uremic Patients

Abstract

Uremic patients are thought to have deficient immune reactivity. The mechanisms for immunosuppression are not known. Various in vitro immune response parameters in lymphocytes from uremic patients and from healthy controls were studied. Using polyclonal activating substances, it was found that PHA [phytohemagglutinin] and [Escherichia coli lipopolysaccharide] LPS responses were reduced in cells from the patient group compared to the control group (P < 0.05). MLC [mixed lymphocyte culture] responsiveness using pooled stimulator cells and polyclonal antibody secretion induced by Staphylococcus aureus in vitro were reduced in the patients (P < 0.05). No differences with regard to proportions of T/B cells in blood were noted between the 2 groups. No correlation was found between responses of individual cells to different activating substances, with the exception of PHA and Con [concanavalin] A. Low responses to PHA were usually accompanied by a general low responsiveness. Patients were further subdivided into groups according to the type of dialysis treatment, peritoneal dialysis (PD) or hemodialysis (HD), and to the duration of the hemodialysis period (< and > 1 yr). Patients treated with PD showed impaired T cell reactivity with lower PHA responses compared to the HD patients (P < 0.05). Between the HD groups there were no significant differences in mitogen or MLC responses. The differences between PD and HD probably were because the PD patients were older and not in the same nutritional state as the HD patients.