Lymphocytopenia in donors undergoing regular platelet apheresis with cell separators

The effect of regular platelet apheresis on lymphocyte count was investigated in 142 platelet donors who donated up to 113 times on Haemonetics Model 30 and Fenwal Model CS-3000 cell separators. Lymphocytopenia (lymphocyte count less than 0.9 X 10(9)/l) was found in 21 out of 113 (18.6%) donors who donated solely on the Haemonetics Model 30 compared with 2 out of 100 (2%) whole blood donors and none of 100 plasmapheresis donors (P less than 0.002). Lymphocyte count was inversely related to the total number of platelet donations (r = 0.51, P less than 0.001) and total estimated lymphocyte loss (r = 0.49, P less than 0.001) suggesting a cumulative effect. T4 and T8 lymphocyte subsets were found to be reduced in each of 13 lymphocytopenic platelet donors tested but T4/T8 ratios were similar to those of controls (2.51 +/- 0.79 and 2.33 +/- 0.58 respectively). No adverse effects on platelet donor health were observed but it is suggested that platelet apheresis protocols should be designed to minimize lymphocyte loss.