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【Objective】 To establish a method for determinating the antigen-dependent cell-mediated cytotoxicity (ADCC) of human immunoglobulin (pH4)for intravenous injection (IVIG) on luciferase reporter gene-modified cell assay. 【Methods】 As effector cells, Jurkat-NFAT-Luc-CD16 cells were used in the assay, and PLC/PRF/5 cells were used as target cells. After incubation of effector cells and target cells with IVIG, the method for determinating ADCC biological activity of IVIG was established by detecting luciferase released by activated T nuclear factor after binding of IVIG Fc fragment to effector cells. Meanwhile, the experimental assay conditions were optimized, and the methodology was verified subsequently. 【Results】 IVIG had a dose-response relationship in this method, which was consistent with four parameter logistic model. And the PLC/PRF/5 cells were finally determined as the target cells. The initial dilution concentration of antibody was 20 mg/mL, and the ratio dilution was 1∶2, and the effector to target ratio was 1∶3, and co-incubation time of two cells and IVIG was 24 hours. Within-run and between-run analysis including three independent tests, initial working concentration relative light unit (RLU) and the relative standard deviation (RSD) of the concentration for 50% of maximal effect(EC50) were less than 11%. The relative titers of the recovery samples of the two different dilution groups were (23.50±1.69)% and (49.30±2.97)%, respectively, and the corresponding recovery rates were (93.50±6.30)% and (96.24±5.43)%, respectively, with RSD less than 11%. 【Conclusion】 The method for determinating ADCC biological activity of IVIG based on luciferase reporter gene-modified cell assay was successfully established. It could be applied in determinating the ADCC biological activity of IVIG, and has the advantages of satisfactory linearity, accuracy, precision and specificity.
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@#Objective To evaluate the stability of human immunoglobulin(pH 4)for intravenous injection(IGIV)after process optimization.Methods A filter plate and B filter membrane were used to filter the protein components in different separation stages to reduce the residue of immunoglobulin A(IgA)in the product in multi-batch large-scale production. The finished product was examined for the physical properties(appearance,visible foreign body,insoluble particle examination and thermal stability test)and the chemical properties[protein content,purity,molecular size distribution,titers of antiHBs,diphtheria antibody,prokallikrein activator(PKA),anti-complement activity(ACA),anti-A and anti-B hemagglutinin,and IgA residue]. The accelerated and long-term stability tests were performed.Results There was no significant difference in the key quality indicators between IGIV batches produced by the optimized process and the normal process,while the IgA residue decreased significantly(t = 3. 992 and 11. 215 respectively,each P < 0. 05). In the accelerated stability and long-term stability tests,all the test results of IGIV after process optimization were qualified,which met the relevant regulations in the third part of Chinese Pharmacopoeia(2020 edition).Conclusion IGIV after process optimization can effectively reduce IgA residue with good stability,which is of great significance for blood product manufacturers to improve the quality of IGIV products.
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【Objective】 To research the effect of the Fc, Fab and F(ab′)2 fragments of immunoglobulin G, the main components of Human Immunoglobulin(pH4) for Intravenous Injection(IVIG), on the phagocytic function of macrophages derived from THP-1 cells. 【Methods】 First of all, IVIG was digested with papain and pepsin to obtain Fc, Fab and F(ab′)2, and these components were then identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Afterwards, propylene glycol monomethyl ether acetate (PMA) was used to induce THP-1 cells to differentiate into M0 macrophages. Finally, the sensitized erythrocytes were labeled with carboxy fluorescein succinimidyl ester (CFSE), and the effect of the above components on the phagocytic ability of M0 macrophages to engulf sensitized erythrocytes was detected by flow cytometry. 【Results】 The identification results of SDS-PAGE showed that the prepared IgG fragments met the requirements of subsequent experiments. Flow cytometry performs showed that the phagocytosis model of M0 macrophages had been successfully established. When the concentration of Fc increased from 0.1μg/ mL to 10μg/ mL, the phagocytosis rate of erythrocytes sensitized by M0 macrophages decreased from (24.21±0.58) % to (12.27±0.19) %. When the concentration of IVIG protein increased from 0.1 μg/ml to 10 μg/ml, the phagocytosis rate decreased from (20.57±0.39) % to (0.20±0.03) %. Meanwhile, at the same protein concentration (10 μg/ml), the inhibitory effect of Fc on phagocytosis was only half that of IVIG. In addition, Fab, F(ab′)2, and human serum albumin could not inhibit phagocytosis of M0 macrophages. 【Conclusion】 IVIG can effectively inhibit the phagocytosis of THP-1 derived M0 macrophages, which is mainly dependent on the Fc, but not related to the Fab of IgG and F (ab′)2.
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OBJECTIVE:To observe the efficacy and safety of prednisone combined with human immunoglobulin(pH4)for intra-venous injection in the treatment of idiopathic thrombocytopenic purpura. METHODS:85 patients with idiopathic thrombocytopenic purpura were divided into control group(42 cases)and observation group(43 cases). Control group received 1.6 mg/(kg·d)Predni-sone tablet,orally,for continuous 4 weeks;observation group received 400 mg/(kg·d)human immunoglobulin(pH4)for intravenous injection,intravenous injection,for continuous 5 d,then 1.6 mg/(kg·d)Prednisone tablet,orally,for continuous 4 weeks. All pa-tients were given Adrenal color hydrazone tablet,Vitamin C tablet and other conventional treatment. Clinical efficacy,platelet number, T lymphocyte subsets(CD3+,CD3+CD4+,CD3+CD8+,CD19+),TNF-α,IL-6 before and after treatment,time of platelet number reached normal and reached peak value,peak value of platelet number and the incidence of adverse reactions in 2 groups were ob-served. RESULTS:The total effective rate and peak value of platelet number in observation group were significantly higher than control group,time of platelet number reached normal and reached peak value were significantly shorter than control group,the differences were statistically significant(P0.05);after treatment,platelet number,CD3+and CD3+CD4+in 2 groups were significant-ly higher than before,and observation group was higher than control group,IL-6,TNF-αlevel,CD3+CD8+and CD19+were signifi-cantly lower than before,and observation group was lower than control group,the differences were statistically significant(P0.05). CONCLUSIONS:Prednisone com-bined with human immunoglobulin(pH4) for intravenous injection shows better efficacy than prednisone alone in the treatment of idio-pathic thrombocytopenic purpura,it can increase platelet number,adjust immune function,and do not increase the incidence of ad-verse reactions.