Liu Fang, Feys Hendrik B, Dong Ning-zheng, Bai Xia, Vanhoorelbeke Karen, Deckmyn Hans, Ruan Chang-geng
Jiangsu Institute of Hematology, First Affiliated Hospital of Soochow University, Suzhou 215006, China.
Zhonghua Xue Ye Xue Za Zhi. 2006 Mar;27(3):154-7.
To investigate the antigen levels and activity of von Willebrand factor cleaving protease ADAMTS13 in thrombotic thrombocytopenic purpura (TTP) patients and carriers.
28 samples from 13 TTP patients and 10 samples from the carriers were examined. The activity of ADAMTS13 was measured by residue collagen binding assay, and antigen by a newly developed sandwich ELISA.
The mean ADAMTS13 level in Chinese normal controls (CN) was (600.93 +/- 145.36) mU/ml (n = 26) comparable to the level (1000 mU/ml) in pooled normal Caucasian plasma, and the activity was (74.79 +/- 11.81)%. Both the antigen level and activity of ADAMTS13 in congenital TTP patients either before plasma exchange (pre-PE) or interval relapse were quite lower than those in normal control, but were increased after PE (post-PE). The antigen was (331.40 +/- 109.85) mU/ml (P < 0.01, n = 10), and activity was (66.79 +/- 12.82)% (P > 0.05). The ADAMTS13 levels pre-PE in idiopathic TTP was (98.7 +/- 82.08) mU/ml (n = 11, P < 0.01), and that post-PE was up to (449.4 +/- 232.33) mU/ml (P < 0.01, n = 10). The activity of ADAMTS13 in patients pre-PE and post-PE were (22.23 +/- 19.07)% (P < 0.01) and (60.92 +/- 22.33)% (P > 0.05) respectively. In a secondary TTP patient the ADAMTS13 antigen was much higher than that in CN, and the activity was 6.00%.
The antigen and activity of ADAMTS13 in most TTP patients pre-PE are deficient, and these two indices in most TTP patients are paralleled. The reason for ADAMTS13 deficiency is congenital shortage or clearance by immune system, but it is unknown that why in some patients the ADAMTS13 antigen is extremely high but its activity is quite low.
研究血栓性血小板减少性紫癜（TTP）患者及携带者中血管性血友病因子裂解蛋白酶ADAMTS13的抗原水平及活性。
检测了13例TTP患者的28份样本及携带者的10份样本。采用残余胶原结合试验检测ADAMTS13的活性，采用新开发的夹心ELISA法检测抗原。
中国正常对照（CN）中ADAMTS13的平均水平为（600.93±145.36）mU/ml（n = 26），与正常高加索人混合血浆中的水平（1000 mU/ml）相当，活性为（74.79±11.81）%。先天性TTP患者在血浆置换前（PE前）或间歇复发时ADAMTS13的抗原水平和活性均显著低于正常对照，但血浆置换后（PE后）升高。抗原为（331.40±109.85）mU/ml（P < 0.01，n = 10），活性为（66.79±12.82）%（P > 0.05）。特发性TTP患者PE前ADAMTS13水平为（98.7±82.08）mU/ml（n = 11，P < 0.01），PE后高达（449.4±232.33）mU/ml（P < 0.01，n = 10）。患者PE前和PE后ADAMTS13的活性分别为（22.23±19.07）%（P < 0.01）和（60.92±22.33）%（P > 0.05）。1例继发性TTP患者的ADAMTS13抗原远高于CN，活性为6.00%。
大多数TTP患者PE前ADAMTS13的抗原和活性均缺乏，且这两个指标在大多数TTP患者中呈平行关系。ADAMTS13缺乏的原因是先天性不足或免疫系统清除，但部分患者ADAMTS13抗原极高而活性极低的原因尚不清楚。
