Tidow N, Pilz C, Kasper B, Welte K
Department of Pediatric Hematology and Oncology, Hannover Medical School, Germany.
Stem Cells. 1997;15 Suppl 1:113-9; discussion 120. doi: 10.1002/stem.5530150815.
Point mutations in the gene for the G-CSF receptor have been reported previously in a subgroup of patients with severe congenital neutropenia. Here, we investigated the frequency of these specific G-CSF receptor mutations in patients with neutropenic disorders undergoing treatment with recombinant human (r-metHu)G-CSF (Filgrastim). Nucleotides 2306 to 2561, including the critical region (nucleotides 2384-2429) from the intracellular domain of the G-CSF receptor gene, were amplified by reverse transcriptase-polymerase chain reaction, and DNA was sequenced directly and after transformation in E. coli. Four of 30 patients with severe congenital neutropenia displayed a point mutation in the tested cytoplasmic region of the G-CSF receptor gene. Two of the four patients with a mutated G-CSF receptor developed acute myeloid leukemia secondary to congenital neutropenia. G-CSF receptor analyses were performed in myeloid cells taken at different time points in the four patients with the mutated receptor, and no correlation between occurrence of the mutation and time or dose of r-metHuG-CSF treatment was found. No point mutations in the G-CSF receptor critical domain could be detected in cells from the other 26 congenital neutropenia patients. Additionally, no G-CSF receptor point mutations could be seen in neutrophils, blood and bone marrow mononuclear cells from patients with cyclic or idiopathic neutropenia, and bone marrow mononuclear cells from patients suffering from severe aplastic anemia. Similar results were obtained by Touw et al., demonstrating that five out of 25 patients with congenital neutropenia reveal G-CSF receptor mutations. These data show that the point mutations in the critical region of the intracellular part of the G-CSF receptor occur only in a subgroup of severe congenital neutropenia patients. Furthermore, our data suggest that the described G-CSF receptor point mutations are not correlated with the start, duration or doses of r-metHuG-CSF treatment, but might result from genetic instability in the G-CSF receptor gene in severe congenital neutropenia.
先前已有报道称，严重先天性中性粒细胞减少症患者亚组中存在粒细胞集落刺激因子（G-CSF）受体基因的点突变。在此，我们调查了接受重组人（r-metHu）G-CSF（非格司亭）治疗的中性粒细胞减少症患者中这些特定G-CSF受体突变的频率。通过逆转录聚合酶链反应扩增G-CSF受体基因胞内结构域的核苷酸2306至2561，包括关键区域（核苷酸2384 - 2429），并直接对DNA进行测序，以及在大肠杆菌中转化后测序。30例严重先天性中性粒细胞减少症患者中有4例在G-CSF受体基因的检测胞质区域显示出点突变。4例G-CSF受体突变患者中有2例继发于先天性中性粒细胞减少症而发生急性髓系白血病。对4例受体突变患者在不同时间点采集的髓系细胞进行G-CSF受体分析，未发现突变的发生与r-metHuG-CSF治疗的时间或剂量之间存在相关性。在其他26例先天性中性粒细胞减少症患者的细胞中未检测到G-CSF受体关键结构域的点突变。此外，在周期性或特发性中性粒细胞减少症患者的中性粒细胞、血液和骨髓单个核细胞以及严重再生障碍性贫血患者的骨髓单个核细胞中也未发现G-CSF受体点突变。Touw等人也得到了类似结果，表明25例先天性中性粒细胞减少症患者中有5例存在G-CSF受体突变。这些数据表明，G-CSF受体胞内部分关键区域的点突变仅发生在严重先天性中性粒细胞减少症患者的一个亚组中。此外，我们的数据表明，所描述的G-CSF受体点突变与r-metHuG-CSF治疗的开始、持续时间或剂量无关，但可能是由于严重先天性中性粒细胞减少症中G-CSF受体基因的遗传不稳定性所致。
