Thromboxane B-2 and platelet derived growth factor in essential thrombocythemia under anagrelide treatment.

We present herein studies carried out in 17 patients with essential thrombo cythemia before treatment with anagrelide and on remission. Ten patients ha d symptoms related to thrombocythemia, 8 of them at the time of starting tr eatment. The plasmatic levels of TXB2 and PDGF were measured by ELISA techn ique. Before treatment, PDGF values corrected for the platelet count were l ower than controls, 0.48 ng/10(5) platelets (0.13-1.93) and 0.92 ng/10(5) p latelets (0.33-1.16) respectively (p = 0.02), and they were not different f rom the results obtained during remission. Count-corrected TXB2 levels befo re treatment were higher than the control group, 1.0 ng/10(5) platelets (0. 04-14.4) and 0.25 ng/10(5) platelets (0.13-0.39) respectively (p = 0.04); t hese values decreased during remission 0.86 ng/10(5) platelets (0.07-9.8) ( p = 0.04), although they were still above normal values (p = 0.008). Sympto ms disappeared with the normalization of platelet counts in all cases. Thes e results show that patients with essential thrombocythemia during remissio n have a tendency to normalize the count-corrected TXB2 values.