Supplementary Material for: Microinflammation in Hemodialysis Patients Is Associated with Increased CD14⁺CD16⁺ Pro-Inflammatory Monocytes: Possible Modification by On-Line Hemodiafiltration

Background: An increased percentage of pro-inflammatory CD14⁺CD16⁺ monocytes might contribute to inflammation in hemodialysis (HD) patients. The purpose of the study was to evaluate the possible contribution of pro-inflammatory monocytes to inflammation in HD patients and also to evaluate the effect of on-line hemodiafiltration (HDF). Methods: Flow cytometric detection of monocytes in patients undergoing HD, on-line HDF and healthy controls as well as plasma cytokines and cytokine mRNA measurement were performed. Results: Percent pro-inflammatory monocytes, plasma cytokines and cytokine mRNA significantly increased in HD patients. Intracellular cytokine staining showed pro-inflammatory monocytes were the predominant source of tumor necrosis factor-α. Percent pro-inflammatory monocytes positively correlated with plasma inflammatory cytokines. Percent pro-inflammatory monocytes, plasma cytokines and cytokine mRNA significantly decreased in on-line HDF patients. Conclusion: Increased pro-inflammatory monocytes are likely to contribute to inflammation in HD patients, and beneficial effect of on-line HDF might be partially mediated by modulating the inflammatory response.