Dialysis-induced eosinophilia.

Blood eosinophils were counted by the counting-chamber method in 21 regular hemodialysis patients. Before dialysis, eosinophil counts were within the normal range in all patients (mean 98 cells/mm3, range 6-350). After the first 15 min of hemodialysis, with not reused coils or hollow-fiber dialysers, a significant drop in eosinophil counts was noted in all patients. The mean drop was 37.5% of the initial value (range 28-100%). At the end of the 5-hour dialysis, the eosinophil counts rose significantly in all patients but 1. The mean rise was 521% of the initial counts (range 22.3-1576%). Simultaneous neutrophil counts showed the already described drop at 15 min with a return to predialysis levels at 5 h. Predialysis IgE serum concentrations were lower than normal (mean 24.8, range 4.5-58 units/ml), and did not change at the end of the dialysis. It seems that pulmonary sequestration is responsible for both neutropenia and eosinopenia early in dialysis. The marked eosinophilia at 5 h may be the result of a release of eosinophilotactic substances induced by the dialysis procedure itself.