Release of granulocyte proteinases during hemodialysis

Neutral proteinases of neutrophilic polymorphonuclear leukocytes were followed up cytochemically in blood smears of 12 patients submitted to regular hemodialysis treatment (RDT). Halo formation (ring-shaped area around each neutrophil due to protein degradation) was reduced in all patients with end-stage renal disease under RDT. Concomitant to the development of leukopenia, a maximal increase of the plasma levels of the granulocytic elastase in complex with alpha 1-proteinase inhibitor was observed 3 h after starting hemodialysis (+409%; p less than 0.001). On the other hand, the proteolytic activity of the plasma samples against azocasein as substrate, being significantly higher (+244%; p less than 0.001) in RDT patients compared with healthy controls, decreased permanently during therapy (-71%; p less than 0.001; 3 h after initiation of the treatment). The mechanisms of release as well as of elimination of proteolytic activity due to RDT are discussed.