再生障碍性贫血患者端粒及端粒酶活性的变化

目的观察再生障碍性贫血（aplasticanemia，从）患者外周血单个核细胞（peripheralbloodmononuclearcell，PBMC）端粒长度及端粒酶活性的变化，探讨AA的发病机制及治疗的新靶点。方法选取2010—09／2013—03月5所医院血液科确诊的71例AA患者，男性36例，女性35例，年龄12-82（39．48±18．78）岁，根据2009年英国再生障碍性贫血诊疗指南分组，其中非重型再生障碍性贫血（non-severeaplasticanemia，NSAA）组35例，重型再生障碍性贫血（severeaplasticanemia，SAA）组26例，极重型再生障碍性贫血（verysevereaplasiaanemia，VSAA）组10例。同时选取性别、年龄与之匹配的34例门诊健康体检者作为正常对照组，其中男性17例，女性17例，年龄10-73（40．68±19．00）岁。于初诊时留取外周血标本3ml。分别采用流式荧光原位杂交法（flow-fluorescenceinsituhybridization，Flow-FISH）检测PBMC端粒长度，端粒重复序列扩增技术（telomeraserepeatamplificationprotocol，TRAP）一多聚酶链式反应（poly—merasechainreaction，PCR）-酶联免疫吸附剂测定（enzyme-linkedimmunosorbentassay，ELISA）法检测其端粒酶活性。结果①不同性别者外周血端粒长度无明显差别（t=0．548，P=0．585）。②外周血端粒长度与年龄呈负相关（b=-0．387，P=0．001），不同组间比较，正常对照组端粒长度随年龄增长下降幅度要稍大于NSAA和SAA＋VSAA组，NSAA、SAA＋VSAA组端粒随年龄的变化趋势一致。③控制年龄对外周血端粒长度的影响，多重比较发现NSAA、SAA＋VSAA组外周血端粒长度均显著短于正常对照组（P均〈0．001）。④随机选取NSAA组23例，SAA＋VsAA组28例，性别年龄与之匹配的34例正常对照组检测端粒酶活性，34例正常对照组中阳性6例（17．6％），23例NSAA组中阳性11例（47．8％），28例SAA＋VSAA组中阳性21例（75．O％）。3诊断组外周血酶活性阳性率有统计学差别（x^2=20．555，P〈O．001）。⑤各诊断组年龄和性别对端粒酶活性无明显影响，多重比较示SAA＋VSAA组（P〈0．001）、NSAA组（P=0．002）端粒酶活性均显著高于正常对照组。结论再生障碍性贫血患者PBMC端粒长度缩短，端粒酶活性增高，端粒及端粒酶可能成为再障治疗的新靶点。

Changes of Telomere and Telomerase Activity in Patients with aplastic Anemia

Objective To Observe the change of telomere length and telomerase activity of the peripheral blood mononuclear cell （PBMC） in patients with aplastic anemia （AA）, explore the pathogenesis and provide new therapy tar- gets. Methods A total of 71 AA patients diagnosed between September 2010 and March 2013 in 5 hospitals were studied with 36 males and 35 females, 12-82 （39. 48 ± 18. 78） years old. They were divided into non-severe aplastic anemia （NSAA） group （35 cases）, severe aplastic anemia （SAA） group （26 cases） and very severe aplasia anemia （VSAA） group （10 cases） according to the Guidelines for the diagnosis and management of aplastic anaemia in 2009. Thirty-four healthy volunteers with matched age and sex were selected as normal control, 17 males and 17 females, 10-73 （40. 68 ± 19. 00） years old. 3 ml peripheral blood specimens were collected at their first clinic. The relative telomere length was detected by flow-fluorescence in situ hybridization （Flow-FISH）. The telomerase activity was detected by telomerase repeat amplification protocol-polymerase chain reaction- enzyme-linked immunosorbent assay （TRAP-PCR-ELISA） method. Results （1） The telomere length in peripheral blood had no significant difference between different genders （t = 0. 548, P = 0. 585）. （2） Telomere length and age had negative correlation （b = - 0. 387,P = 0. 001） in control group, NSAA group and SAA ＋ VSAA group. The decreased magnitude of telomere length with the growth of age was larger in control group than that in NSAA and SAA ＋ VSAA groups. NSAA and SAA ＋ VSAA groups had the same trends of telomere length with age. （3） After the correction of the effect of age, the telomere length in NSAA and SAA ＋ VSAA groups was significantly shorter than that in the control group （P〈0. 001）. （4） Telomerase activity was tested in randomly selected 23 cases in NSAA group, 28 cases in SAA ＋ VSAA group, and 34 healthy volunteers with matched gender and age. Six positive cases in control group （17. 6 %, 6/34）, 11 positive cases in NSAA group （47. 8%, 11/23）, and 21 positive cases in SAA ＋ VSAA group （75.0%, 21/28） were found. The positive rates were significantly different among three groups （x^22 = 20. 555, P〈0. 001）. （5） Age and gender had no significant effect on the telomerase activity. The multiple comparison indicated the telomerase activity in SAA ＋ VSAA group （P〈0. 001） and NSAA group （P = 0. 002） was significantly higher than that in the control group. Conclusion Telomere length of PBMC in AA patients is shortened, and the telomerase activity is increased. Telomere and telomerase may become the new treatment targets of AA.