多发性骨髓瘤患者外周血中TCR Vβ亚家族nave T细胞水平变化

目的： 检测多发性骨髓瘤（MM）患者外周血中23个TCR Vβ亚家族的T细胞受体删除DNA环（sjTRECs）的存在特点，从而了解MM患者相应Vβ亚家族nave T细胞的近期胸腺输出情况。方法: 利用半巢式PCR分别扩增12例MM患者每5×104个外周血单个核细胞（PBMCs）中的23个Vβ亚家族sjTRECs，10例正常人外周血作为对照。结果: 在5×104个PBMCs中，检测到MM患者sjTRECs的Vβ亚家族数量约为（5.00±2.45）个，与正常人的（9.60±5.48）个相比，检出的亚家族数量明显减少（P<0.05）；23个Vβ亚家族sjTRECs在正常人中均可以检测到，而在MM患者仅检测到部分；并且Vβ2、Vβ10、Vβ16、Vβ17和Vβ21等5个亚家族sjTRECs的检出率明显低于正常水平。12例MM患者检出的亚家族数量（2-9个）不等，患者的年龄与检出的亚家族数量存在负相关（r=-0.892；P<0.01）。结论: MM患者胸腺近期输出的23个Vβ亚家族nave T细胞存在不同程度的缺失或水平降低，表明患者存在不同程度的细胞免疫功能缺陷以及T细胞谱系重建的能力和潜能受损。

Changes in TCR Vβ subfamily nave T cells in peripheral blood of patients with multiple myeloma

AIM: To detect the existence of signal joint T-cell receptor excision DNA circles (sjTRECs) of 23 TCR Vβ subfamilies in mononuclear cells of patients with multiple myeloma (MM), and to evaluate the recent thymic emigrants of corresponding Vβ subfamily nave T cells in MM patients. METHODS: 23 TCR Vβ subfamily sjTRECs were amplified in genomic DNA from 5×104 PBMCs of 12 cases in MM patients by using semi-nest PCR.10 normal individuals served as controls. RESULTS: The number of detectable Vβ subfamily sjTRECs was 5.00±2.45 from MM patients, as compared with 9.60±5.48 from normal individuals, the difference was significant (P<0.05). The frequencies of Vβ2-, Vβ10-, Vβ16-, Vβ17-, and Vβ21-Dβ1 sjTRECs were significantly lower than those from normal individuals. 2-9 Vβ subfamily sjTRECs were detected from 12 cases of MM patients. It was negative correlation between age and the number of detectable Vβ subfamily sjTRECs in MM patients (r=-0.892; P<0.01). CONCLUSION: It has been found that some of 23 Vβ subfamily nave T cells are absent or lower level of recent thymic output function in MM patients, suggesting that MM patients have severe cellular immunodeficiency and the capacity and potential of long-term TCR Vβ repertoire reconstitution are dramatically lowered.