Prchal J T
Division of Hematology/Oncology, Baylor College of Medicine, Houston, Texas 77030, USA.
Intern Med. 2001 Aug;40(8):681-7. doi: 10.2169/internalmedicine.40.681.
Polycythemia is literally translated as "many cells in the blood". Only erythrocytosis (an alternative term for these disorders) produces polycythemia since leukocytes and platelets are present in blood in far smaller proportions. Polycythemia may be due to increased proliferation or decreased apoptosis of erythroid progenitors, or to delayed erythroid differentiation with an increased number of progenitor cell divisions. Prolonged red cell survival, another theoretical cause of polycythemia, has not yet been described and with intact regulatory mechanisms is unlikely to occur. Primary polycythemias result from abnormalities expressed in hematopoietic progenitors. In contrast, circulating factors cause secondary polycythemia (1). There are acquired and congenital causes of both primary and secondary polycythemia (1).
真性红细胞增多症字面意思是“血液中细胞过多”。只有红细胞增多症（这些病症的另一种说法）会导致真性红细胞增多症，因为白细胞和血小板在血液中的占比要小得多。真性红细胞增多症可能是由于红系祖细胞增殖增加或凋亡减少，或者是由于红系分化延迟且祖细胞分裂数量增加。红细胞存活时间延长是真性红细胞增多症的另一个理论原因，但尚未有相关描述，并且在调节机制完好的情况下不太可能发生。原发性真性红细胞增多症是由造血祖细胞中表达的异常引起的。相比之下，循环因子会导致继发性真性红细胞增多症（1）。原发性和继发性真性红细胞增多症都有后天性和先天性病因（1）。
