Monocyte apoptosis in uremia is normalized with continuous blood purification modalities

Uremia is associated with a state of immune dysfunction. Dysregulation of homeostasis may be directly related to abnormal apoptosis regulation in uremia, which is crucial for the maintenance of the biological system. We demonstrated that plasma from three groups of uremic subjects, i.e. hemodialysis (HD) patients, peritoneal dialysis (PD) patients and patients with predialysis chronic renal failure (CRF), has different apoptotic potential on U937 monocytes. The plasma of HD and CRF subjects when incubated with U937 cells induced higher levels of apoptosis compared with that of PD and control subjects (HD 26.08 +/- 11.39, CRF 24.87 +/- 9.07, PD 12.13 +/- 4.51, controls 11.69 +/- 4.02). Furthermore, the phagocytic ability of U937 cells incubated with the various plasma demonstrated an impaired response in the HD and CRF subjects (HD 27.56 +/- 6.67, CRF 30.24 +/- 9.08, PD 36.55 +/- 9.80, controls 40.04 +/- 6.98). These results suggest that continuous blood purification, such as in PD, may have advantages over intermittent therapies in removing uremic apoptotic molecules and potentially maintaining biological function and homeostasis.