Rapid and transient lymphocytopenia after i.v. administration of high doses of human recombinant erythropoietin.

The effect of administration of human recombinant erythropoietin on leukocytic cells has been evaluated. In humans the administration of 20,000 U i.v. of rHuEPO caused a rapid and transitory leukopenia that seemed to be caused by a preferential reduction of lymphocytes (2715 +/- 513 mm3 t 0; 1898 +/- 506 t 60', p < 0.002). Pretreatment with imidazole-2-hydroxybenzoate, a drug capable of inhibiting the synthesis of prostaglandins, caused a less marked and later reduction of lymphocytes (2242 +/- 477 t 0; 1560 +/- 318 t 180 minutes, p < 0.001). A less marked and later lymphocytopenia was also shown in subjects affected by chronic renal insufficiency (2907 +/- 726 t 0; 1944 +/- 512 t 180 minutes, p < 0.005).