Elevated levels of tumor necrosis factor alpha in postdialysis fatigue

Postdialysis fatigue (PDF) has been ascribed to excessive ultrafiltration and decline in osmolality during hemodialysis. We evaluated the potential role for the sommogenic cytokines, interleukin-1 beta (IL-1beta) and tumor necrosis factor alpha (TNFalpha), in the genesis of PDF Patients dialyzing with cuprophane membrane were assigned to PDF (N=25) and non-PDF (N=25) groups based on a fatigue index questionnaire. Pre- and postdialysis samples were obtained from 3 consecutive treatments and later assayed for serum levels of IL-1beta and TNFalpha by ELISA. Our results show significant intradialytic elevation of TNFalpha in both non-PDF groups (non-PDF: pre- 3.36+/-0.80 pg/ml to post 3.75+/-0.88 pg/ml, p<0.04; PDF: pre- 5.95+/-0.80 pg/ml to post- 8.66-/+1.35 pg/ml, p<0.02). The degree of intradialytic augmentation was significantly greater for TNFalpha in the PDF group (46+/-18% vs 11+/-5%; p<0.03). There were no significant intradialytic changes in serum levels of IL-1beta in either the PDF or non-PDF groups. There also were no significant differences in dialysis-related body weights, systolic blood pressures, or osmolalities. These findings suggest that TNFalpha may be involved in the pathogenesis of PDF.