Serum erythropoietin and thrombopoietin levels in patients with essential thrombocythaemia

In 40 patients with essential thrombocythaemia (ET) serum erythropoietin (E PO) and thrombopoietin (TPO) concentrations were determined and compared wi th the EPO and TPO values of a healthy control group. The mean EPO serum co ncentration for 24 control patients was 9.4 mU/ml +/- 3.7 (range 2 - 17.9), for 32 untreated ET patients at diagnosis 6.6 mU/ml +/- 7.6 (range 0.5 - 4 4.3) and for 8 ET patients treated with cytoreduction 14.1 mU/ml +/- 8.0 (r ange 4.5 - 26.1). Serum EPO levels in untreated ET patients at diagnosis we re significantly lower compared with serum EPO levels in healthy control pa tients (p=0.002). Serum EPO levels in treated ET patients were not differen t from serum EPO levels in healthy controls (p=0.13) but were significantly higher compared with untreated ET patients (p=0.003). Serum TPO levels wer e determined in 18 of 40 ET patients, the mean TPO serum concentration was 211 pg/ml +/- 109 (range 62,5 - 345). The mean TPO serum concentration for 10 untreated ET patients at diagnosis was 162 pg/ml +/- 87 (range 62,5 - 30 2) and for 8 ET patients who had received cytoreductive treatment 272 pg/ml +/- 106 (range 96 - 345), respectively (p=0.04). Both serum TPO levers for treated and untreated ET patients were significantly higher (p<0.001) comp ared with serum TPO levels for healthy controls. The results of our study s uggest a difference in the regulation of serum EPO and TPO in patients with ET. While the mean serum EPO level is decreased in untreated ET patients, the corresponding mean serum TPO level is increased. Treatment with cytored uction, results in normalisation of the mean serum EPO level, whereas the m ean TPO serum level remains elevated.