血友病乙基因治疗临床研究

CLINICAL STUDIES ON GENE THERAPY FOR HEMOPHILIA B

用逆转录病毒载体将人ＩＸ因子ｃＤＮＡ转入血友病乙患者皮肤成纤维细胞，体外培养扩增后与胶原混合皮下注射，作了２例临床基因治疗。注射细胞总数分别为１１．４×１０￣８和６×１０￣８，结果患者血浆ＩＸ：Ａｇ和ＩＸ：Ｃ均升高，例１ＩＸ：Ａｇ由８４．２ｎｇ／ｍｌ升至２５１．０ｎｇ／ｍｌ，ＩＸ：Ｃ由２．１９％升至５．９２％。例２ＩＸ：Ａｇ由９８．５ｎｇ／ｍｌ升至１９９．１ｍｇ／ｍｌ，ＩＸ：Ｃ由２．４０％上升至４．１３％。已持续表达逾５００天，临床出血倾向有所改善，至今未发现与基因治疗相关的毒副反应。

kin fibroblasts from two patients with hemophilia B,LD and LW,were transfected with retroviral vectorscontaining human clotting factor IX cDNA,XL-IX andN2CMVIX.The transfected cells of LD and LW pro-duced in vitro 400ng and 300ng/10￣6 cells. 24h of factorIX protein (IX:Ag)respectively. The autologous factorIX secreting fibroblasts(total number:11.4×10￣8 for LD and 6 ×10￣8 for LW)were then mixed with collagenand injected subcutaneously into the respective patient.The plasma concentration of IX:Ag in LD was elevatedfrom 84. 2±16.4ng/ml to 251.0±21.2ng/ml,and theclotting activity IX:C from 2.19±0.31% to 5.92±0.31%. The IX :Ag level in LW was increased from98.5±30.8ng/ml to 199.1±39.8ng/ml,and the IX:Cfrom 2.4%to 4.13%. The gene corrected cells havebeen producing factor IX in both patients for over 16months. The hemorrhagic tendencies of the patientshave been alleviated and no side-effects related to thegene therapy were observed up to now.