title: [Detection of alloantibodies against Factor VIII in plasma of patients with hemophilia A and its relationship with Factor VIIIC domain].
abstract: This study was purposed to detect the alloantibodies against Factor VIII (FVIII) by ELISA for estimating the incidence of the alloantibodies against Factor VIII (FVIII) in patients with hemophilia A, and to investigate the relationship between factor VIIIC domain and alloantibodies. Total of 140 patients with hemophilia A and 80 normal controls were enrolled in this study, among them plasma FVIII level of 84 patients was less than 1%, plasma FVIII level of 34 patients was between 1% and 5%, and plasma FVIII level of 22 patients was more than 5%. All patients were treated with plasma-derived FVIII concentrate or plasma before. The ELISA plate was coated with McAb (SZ-132) against FVIII prepared in our laboratory, then human recombinant FVIII concentrates were applied. After incubation in room temperature for 2 hours, diluted plasma samples and HRP-conjugated goat anti-human IgG were added successively, finally A490 was recorded. The threshold of alloantibody of patient plasma was set as mean value>3 SD more than control. The plate was coated with antibody against His, then human recombinant FVIII-C1C2 prepared in our laboratory was added. After incubation in room temperature for 2 hours, diluted plasma samples and HRP-conjugated goat anti-human IgG were added successively, finally A490 were recorded. The threshold was set as the mean value>3 SD more than control. The results showed that the alloantibodies against FVIII were found in 56 patients (40%) by ELISA, and 82.1% (46/56) of this kind of alloantibody could interact with the C domain of FVIII. It is concluded that C domain of FVIII is one of the primary binding sites for the alloantibodies against FVIII in Chinese patients with hemophilia A.
authors.affiliation: Department of Hematology, Taihe Hospital Affiliated to Hubei Medical University, Shiyan 442000, Hubei province, China; Key Laboratory of Thrombosis and Hemostasis of Ministry of Health, Jiangsu Institute of Hematology, The First Affiliated Hospital of Soochow University, Suzhou 215006, Jiangsu Province, China.
authors.forename: Lu-Lu
authors.initials: LL
authors.lastname: Zhang
authors.forename: Zi-Qiang
authors.initials: ZQ
authors.lastname: Yu
authors.forename: Chu-Cheng
authors.initials: CC
authors.lastname: Wan
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Zheng-Hua
authors.initials: ZH
authors.lastname: Zhang
authors.forename: Chang-Geng
authors.initials: CG
authors.lastname: Ruan
mesh_terms: D000293:Adolescent; D000328:Adult; D001666:Binding Sites, Antibody; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005169:Factor VIII / Q000276:immunology*; D006467:Hemophilia A / Q000097:blood* / Q000276:immunology*; D006801:Humans; D007223:Infant; D007518:Isoantibodies / Q000097:blood*; D008297:Male; D008875:Middle Aged; D054730:Protein Interaction Domains and Motifs; D055815:Young Adult
chemical_list: D007518:Isoantibodies; D005169:Factor VIII