The effect of uremia and hemodialysis on caspase-1 and caspase-3 activity in neutrophils.

Background: Neutrophils in uremia maintain chronic inflammation, which contributes to malnutrition and immunity disorders. The influence of hemodialysis on the life span of neutrophils is unclear, although many authors postulate its apoptotic effect. Erythropoietin (EPO) is an antiapoptotic factor for various cells. We investigated factors possibly interfering in apoptosis of neutrophils in hemodialysis (HD) patients, such as HD session, parathormone (PTH), dose of EPO, inflammation and nutrition.

Subjects And Methods: Twenty HD patients and ten healthy controls were donors of neutrophils. We evaluated caspase-1 and caspase-3 activities, related to apoptosis of neutrophils, before and after a 4-hour HD session with cuprophane or polysulphone dialyzer. We measured serum concentrations of C-reactive protein, cholesterol, albumin, prealbumin and transferrin. Time of dialysis treatment, PTH level and dose of EPO were also evaluated.

Results: We observed a significant increase in caspase-1 activity and decrease in caspase-3 activity in neutrophils after HD with cuprophane, but not with polysulphone. Caspase-1 activity correlated positively with EPO dose and negatively with PTH level. Caspase-3 correlated negatively with the time of dialysis treatment. No correlation between caspase activity and markers of inflammation or nutrition was noticed.

Conclusions: The results suggest that HD with bioincompatible cuprophane may prolong the life span of neutrophils due to the intense inflammatory reaction and high activity of caspase-1. Time of dialysis treatment, PTH level and EPO dose potentially influence the life span of neutrophils. PTH seems to have a proapoptotic effect of neutrophils, while EPO is an antiapoptotic factor.