Leukopenia, hypoxemia, and complement activation during a single hemoperfusion.

White blood cell count, acid-base balance, PO2, and complement function in five uremic patients undergoing a single hemoperfusion employing activated charcoal coated with methacrylate were studied. After 20 min on hemoperfusion, a marked leukopenia [ranging from 6,080 +/- 526 to 3,740 +/- 1,124 (p less than 0.02)] and hypoxemia [ranging from 106 +/- 13.8 to 80.2 +/- 11.9 mm Hg (p less than 0.02)] were observed. At the same time, total hemolytic complement decreased from 135 +/- 15.7 to 123 +/- 14.7 U/ml (p less than 0.001) and alternative pathway activity from 38.1 +/- 5.1 to 33.1 +/- 6.7 U/ml (p less than 0.005). C3 and B cleavage fragments were detected in the samples tested, thus demonstrating the activation of the complement alternative pathway. After 60 min, the different parameters tended to increase but did not reach the baseline levels. A direct correlation between the degree of leukopenia and the reduction of PO2 throughout the hemoperfusion period was found. pH PCO2, and HCO-3 did not change throughout the hemoperfusion period. The results demonstrate that complement activation, leukopenia, and hypoxemia occur during hemoperfusion.