Leukocyte overshoot: a new sign of bioincompatibility in fast hemodialysis.

A high blood flow of 400 ml/min induces leukocytosis after 2 hr of dialysis with leukocyte concentrations of 110-150% of predialysis values. The leukocytosis occurs with both low and high biocompatible membranes, such as Cuprophan, Hemophan, and Polyamide. Cuprophan induces the most profound leukopenia, and also induces the most pronounced leukocytosis. For treatments with a given membrane there was, however, no correlation between leukopenia and leukocytosis. Leukopenia was independent of blood flow, while leukocytosis was strongly influenced by this factor. These observations indicate that different factors cause leukopenia and leukocytosis. Although a larger area induced more leukopenia, the effect was small. Membrane area had no effect on leukocytosis. There were no acute clinical side effects during dialysis that could be related to the leukocyte overshoot. The cause and chronic clinical consequences of leukocyte overshoot are unknown.