PROTHROMBOTIC EFFECT OF ERYTHROPOIETIN IN DIALYSIS PATIENTS

Thrombin-antithrombin III complex concentrations (TAT-III) were measured in 18 anaemic haemodialysis patients treated erythropoietin (Epo) and in four haemodialysis patients treated with i.v. iron dextran. There was a significant early increase in thrombin-antithrombin III in erythropoietin-treated patients which appeared to be independent of the response to erythropoietin (Epo responders (n = 14), pretreatment TAT-III median (range) 3.10 (2.70-9.10) mu-g/l; maximum TAT-III 19.48 (11.18-60.00) mu-g/l, P < 0.001, Wilcoxon; Epo non-responders (n = 4), pretreatment TAT-III 3.15 (2.90-4.50) mu-g/l, maximum TAT-III 16.00 (10.31-36.12) mu-g/l, P < 0.001). This was not seen in iron-dextran-treated patients (Pretreatment TAT-III 2.05 (1.90-9.48)-mu-g/l, maximum TAT-III 5.60 (2.10-14.50)-mu-g/l). The change was not related to haemoglobin, erythropoietin dose, or method of administration, and was transient in nature, thrombin-antithrombin III returning to pretreatment values after approximately 6 months in all patients (Epo responders 6.0(4.0-9.0) months, TAT-III 2.47 (1.30-9.23)-mu-g/l; Epo non-responders 7.0 months, TAT-III 5.04 (2.10-7.00)-mu-g/l). Increased thrombin-antithrombin III complex may reflect an effect of erythropoietin on microcirculatory factors, which could be relevant to the occurrence of adverse events during treatment.