Human Antibodies - Volume 20, issue 1-2

Authors: Roye-Green, K. | Frederick, J. | Wharfe, G. | Choo- Kang, E. | DaCosta, V. | Fletcher, H. | Smikle, M.

Article Type: Research Article

Abstract: Blood samples from 50~women who had had recurrent spontaneous abortions and 135 healthy multiparous women were investigated for anticardiolipin (aCL) antibodies and anti-β2 Glycoprotein 1 (anti-β2 GP1) dependent aCL antibodies by enzyme-linked immunosorbent assays (ELISA), lupus anticoagulant activity was measured by activated partial thromboplastin time, antinuclear antibodies, rheumatoid factors and thyroid antibodies using standard techniques. Serological tests for syphilis were performed on all sera and thyroid function was evaluated. There was no significant difference in the prevalence of autoantibodies in habitual aborters and control subjects (60% and 44%, respectively). Habitual aborters differed from controls only in the prevalence …of positive aCL antibody tests (15/50, 30% vs. 15/135, 11%; χ2 = 8.5, P= 0.01); medium/high concentrations of aCL antibodies (9/50, 18% vs. 9/135, 7%; χ2 4.3, P= 0.05); aCL antibodies of the IgM isotype (8/50, 16% vs. 7/135, 5%; χ2 = 4.5, P= 0.05) and anti-β2- GPI antibodies (7/50, 14% vs. 3/135, 2%; χ2 = 6.1, P= 0.05). We recommend aCL antibody screening in habitual aborters and the performance of the anti-β2 GP1 antibody tests to identify those most at risk. Show more

DOI: 10.3233/HAB-2011-0236

Citation: Human Antibodies, vol. 20, no. 1-2, pp. 1-5, 2011

Authors: Tran, L. | Vogel, W.V. | Sinaasappel, M. | Muller, S. | Baars, J.W. | van Rijswijk, M. | Dinant, H.J. | Beijnen, J.H. | Huitema, A.D.R.

Article Type: Research Article

Abstract: Rheumatoid arthritis is a destructive inflammatory joint disorder. Pre- and mature B-cells, characterized by CD20 antigen expression, play an important role in the inflammatory process. Rituximab, a chimeric monoclonal antibody against the CD20 antigen, has been approved since 2006 for the treatment of patients with rheumatoid arthritis. However, not all patients benefit from this treatment. Persistent activity of the disease has been reported despite treatment with rituximab. Imaging of radiolabeled rituximab can be used to monitor the biodistribution of rituximab, and potentially to predict the efficacy of the treatment. In this study, rituximab was radiolabeled with 124 Iodine for positron …emission tomography (PET) imaging. The aim of this study was to investigate the pharmacokinetics and biodistribution of 124 I-rituximab in patients with rheumatoid arthritis, to establish the optimal procedure for PET imaging. Eligible patients received 50 MBq 124 I-rituximab, corresponding to approximately 1.5 mg rituximab. Wholebody PET/CT imaging was performed at 10 min, 24 hrs, and 48 hrs post injection. The total body activity, radioactivity in whole blood, and rituximab serum levels were determined. 124 I-rituximab has favorable pharmacokinetics for targeting of (pathological) B cells and imaging over several days, but only after pre-treatment with unlabeled rituximab. In addition, protection of the thyroid is recommended to prevent uptake of released 124 I. Show more

Keywords: Rituximab, rheumatoid arthritis, PET imaging, pharmacokinetics, biodistribution

DOI: 10.3233/HAB-2011-0237

Citation: Human Antibodies, vol. 20, no. 1-2, pp. 7-14, 2011

Authors: Hof, Danielle | Cooksley-Decasper, Seraina | Moergeli, Sandra | von Eckardstein, Arnold

Article Type: Research Article

Abstract: Nitrotyrosine is a posttranslational protein modification that occurs under oxidative and nitrosative stress, and plays an important role in numerous pathological conditions. To analyse nitrotyrosine formation several commercial monoclonal and polyclonal antibodies reacting with 3-nitrotyrosine have been developed which however do not work properly in all required assays. Here, antibody phage display was used to select recombinant antibodies that specifically react with nitrotyrosine in various protein contexts. Nine initial selections were carried out, using synthetic peptides, peroxynitrite-modified proteins and conjugated proteins as antigens. Four antibodies were isolated that each exhibited a characteristic binding reactivity that greatly depended on the antigens …that were used for their selections. In general, the selections using small, synthetic and biotinylated peptides were the most successful approach. Subsequently, antibody 11B1 was affinity matured by error prone mutagenesis, resulting in the isolation of two antibodies, designated 47A7 and 47B1. Competition ELISA and immunoblotting after treatment with sodium dithionite further demonstrated the specificity of antibody 47B1 for nitrotyrosine. The results presented here demonstrate that antibody phage display is a useful method to isolate antibodies against posttranslational modifications, which are powerful tools in the proteomic era. Show more

Keywords: Antibody phage display, scFv, nitrotyrosine, oxidative stress

DOI: 10.3233/HAB-2011-0238

Citation: Human Antibodies, vol. 20, no. 1-2, pp. 15-27, 2011

Authors: Tran, L. | Huitema, A.D.R. | van Rijswijk, M.H. | Dinant, H.J. | Baars, J.W. | Beijnen, J.H. | Vogel, W.V.

Article Type: Research Article

Abstract: Introduction: Visualization of the CD20-antigen expression could provide a tool to localize sites of inflammation and could be of additive value in the diagnosis, and subsequently, in the treatment follow-up of patients with rheumatoid arthritis. In this study, an anti-CD20 monoclonal antibody, rituximab (Mabthera® ), was radiolabeled with 124 Iodine. We report the first results of 124 I-rituximab PET/CT in patients with rheumatoid arthritis. Methods: Eligible patients received 50 MBq 124 I-rituximab. Wholebody PET/CT imaging was performed at 10 min, 24 h, 48 h and 72–96 h post injection. Images were evaluated primarily on a visual basis and …were correlated with disease activity as determined by physical examination and clinical measures. Results: Joints with visually detectable targeting of 124 I-rituximab were observed in 4 out of 5 evaluable patients. Only the images at 24 h and later showed accumulation in joints, indicating that the visualized signal represented active targeting of rituximab to the CD20 antigen. Several images showed CD20 positive B-cell infiltration in joints which were clinically normal, while a few clinically diagnosed arthritis localizations were not visualized. This discrepancy suggests that infiltration of CD20 positive B-cells in synovium is a phenomenon that is at least partially independent of clinical inflammation. The level of uptake in joints was generally low, representing less than 0.5% of the injected dose. Conclusion: We have shown the feasibility of CD20 antigen imaging using 124 I-rituximab in patients with rheumatoid arthritis. Further research is needed to elucidate the clinical significance of demonstrated B-cell infiltration in rheumatic joints. Show more

DOI: 10.3233/HAB-2011-0239

Citation: Human Antibodies, vol. 20, no. 1-2, pp. 29-35, 2011

Authors: Tran, L. | Baars, J.W. | de Boer, J.P. | Hoefnagel, C.A. | Beijnen, J.H. | Huitema, A.D.R.

Article Type: Research Article

Abstract: Purpose: To report the pharmacokinetics of 131 I-rituximab a patient with a CD20 positive non-Hodgkin Lymphoma who has received 131 I-rituximab as consolidation treatment after remission induction and to evaluate the effect of radioiodination on the biological properties of rituximab. Results: The patient was a 65-year-old male with a relapsed CD20 positive follicular non-Hodgkin Lymphoma. After induction therapy the patient was in partial remission. Following administration of a diagnostic dose of 185 MBq 131 I-rituximab, remaining lesions were identified on the wholebody scans. The patient then received a therapeutic dose of 1000 MBq 131 I-rituximab. The uptake by …the tumor in the right axilla was 0.17–0.21% of the injected dose. The calculated biological half-life of 131 I-rituximab was 684 hrs. This biological half-life corresponded well with the half-life of unlabeled rituximab which was approximately 720 hrs. Discussion and conclusion: Even though radioiodination of rituximab results in a reduced binding capacity, whole body scans demonstrated localization of 131 I-rituximab in the tumor area. This observation supports the specific targeting of 131 I-rituximab. The half-life of 131 I-rituximab corresponded to the half-life of unlabeled rituximab. Hence, the pharmacokinetics of 131 I-rituximab was not relevantly affected by the radioiodination process. Show more

DOI: 10.3233/HAB-2011-0240

Citation: Human Antibodies, vol. 20, no. 1-2, pp. 37-40, 2011