Thiele J, Kvasnicka H M, Schmitt-Gräff A
Zentrum für Pathologie, Universität zu Köln, Joseph-Stelzmann-Strasse 9, 50924 Köln, Germany.
Pathologe. 2002 Nov;23(6):426-32. doi: 10.1007/s00292-002-0584-7. Epub 2002 Oct 16.
Thrombocythemia in the course of chronic myeloproliferative disorders like chronic idiopathic myelofibrosis (cIMF) and of course essential thrombocythemia (ET), are characterized by life-threatening complications. In a number of clinical trials the recently introduced drug Agrylin((R)) has proven to be very effective. The normalization of the platelet count was related to an interference with megakaryocyte maturation leading to a left-shifting of this cell lineage and/or a reduced proliferation. However, until now no systematic study has been performed on the relationship between development of megakaryopoiesis and proliferative activity. In this investigation we included 10 patients with cIMF and 5 patients with ET that had received Agrylin((R)) for a period ranging between 6 and 70 months. Following therapy this cohort revealed a decrease in the platelet count from 1,104x10(9)/l at diagnosis to 485x10(9)/l. In this context we focused on an immunohistochemical and morphometric analysis of the CD61(+) megakaryopoiesis involving also endomitotic reduplication, by applying a double-immune incubation technique with the proliferating cell nuclear antigen (PCNA). Moreover, we determined the changes of fiber density during observation time. According to our results, the thrombocytopenic effect of Agrylin((R)) is based on an arrest in the dynamics of megakaryocyte maturation towards large (mature) platelet-shedding (polyploid) cells. This pathomechanism causes a significant increase in the number of promegakaryoblasts and megakaryoblasts. On the other hand, the total amount of CD61(+) megakaryocytic cells is not increased. Related to the peculiar cell biology of endomitotic reduplication during the maturation process and its different periods alloted to each single step, PCNA activity (late G1- and S-phase of the cell cycle) is found to be enhanced in the megakaryocyte precursors. Finally, no significant influence of Agrylin((R)) on the evolution of myelofibrosis is detectable and there is a general improvement of hematological data especially in cIMF.
在慢性骨髓增殖性疾病如慢性特发性骨髓纤维化（cIMF）以及原发性血小板增多症（ET）过程中出现的血小板增多症，其特征为具有危及生命的并发症。在多项临床试验中，最近引入的药物阿那格雷（Agrylin((R))）已被证明非常有效。血小板计数的正常化与对巨核细胞成熟的干扰有关，导致该细胞谱系向左偏移和/或增殖减少。然而，到目前为止，尚未对巨核细胞生成的发展与增殖活性之间的关系进行系统研究。在本研究中，我们纳入了10例接受阿那格雷（Agrylin((R))）治疗6至70个月的cIMF患者和5例ET患者。治疗后，该队列的血小板计数从诊断时的1104×10⁹/L降至485×10⁹/L。在此背景下，我们通过应用增殖细胞核抗原（PCNA）的双重免疫孵育技术，对涉及核内复制再复制的CD61(+)巨核细胞生成进行了免疫组织化学和形态计量分析。此外，我们还确定了观察期内纤维密度的变化。根据我们的结果，阿那格雷（Agrylin((R))）的血小板减少作用基于巨核细胞成熟向大（成熟）血小板释放（多倍体）细胞的动态停滞。这种发病机制导致早幼巨核细胞和巨核母细胞数量显著增加。另一方面，CD61(+)巨核细胞的总数并未增加。与成熟过程中核内复制再复制的特殊细胞生物学及其分配给每个步骤的不同时期相关，发现巨核细胞前体中的PCNA活性（细胞周期的G1晚期和S期）增强。最后，未检测到阿那格雷（Agrylin((R))）对骨髓纤维化演变有显著影响，并且血液学数据总体有所改善，尤其是在cIMF患者中。
