Establishment and Clinical Application of Flow Cytometric Immunobead Array in Detecting Plasma von Willebrand Factor Antigen / 中国实验血液学杂志

ABSTRACT

OBJECTIVE@#To establish a novel flow cytometric immunobead array (FCIA) for detecting plasma von Willebrand factor antigen (vWFAg), and to analyze the clinical value of FCIA in predicting the prognosis of patients with ischemic stroke (IS).@*METHODS@#Anti-human vWF monoclonal antibody SZ29 IgG was coated on microspheres overnight, the diluted plasma was added after blocking, then incubated with FITC-conjugated sheep-anti-human vWF IgG polyclonal antibody, and finally detected by flow cytometry. The plasma vWF in 21 case of von Willebrand disease (vWD) and 105 controls (CTL) were detected by FCIA and ELISA, so as to carry out methodological assessment. Plasma vWFAg of 61 IS patients was detected by FCIA and the data of prognosis followed-up for 2-year were collected.@*RESULTS@#The linear fitting of FCIA was good (R2=0.99) without significant difference between FCIA and ELISA. The Bland-Altman bias was 1.12% with 95% limits of agreement that spanned from -45.06% to 47.30%, and the slope of the linear regression was 0.97 (r=0.86, P＜0.01). Importantly, the FCIA method was faster than ELISA, and superior to the ELISA in the detection of low levels of vWFAg. The levels of vWFAg, vWFGPIbR and vWFCB in IS patients were significantly higher than those in healthy controls (Z=8.36, 8.71, 6.22, respectively, P＜0.01).@*CONCLUSION@#The FCIA for detecting plasma vWFAg is not only an effective supplement to ELISA, but also the efficiency is faster and more sensitive, thus improves the diagnosis of type 3 vWD. Elevated levels of vWF Ag in IS patients indicate the poor recovery of daily activities and prognosis.