Aim To determine if cytokine release with a solid phase assay is predictive of adverse responses for a range of therapeutic mAbs.Methods Cytokine ELISAs and a multi-array system were used to compare responses generated by different therapeutic mAbs using a solid phase assay. Flow cytometry was employed to determine the cellular source of those cytokines.Results Only TGN1412 and muromonab-CD3 stimulated CD4+ T-cell mediated cytokine release characterized by significant (all P < 0.0001) IFNγ, TNFα, IL-2, IL-4, IL-5, IL-10, IL-12, IL-13, IL-17 and IL-22 release, comparable with T-cell mitogen. Significantly greater (P < 0.0001) IL-2 release with TGN1412 (2894–6051 pg ml−1) compared with muromonab-CD3 (62–262 pg ml−1) differentiated otherwise comparable cytokine responses. Likewise, TGN1412 stimulated significantly more (P = 0.0001) IL-2 producing CD4+ T-cells than muromonab-CD3 and induced Th1, Th2, Th17 and Th22 subsets that co-release this cytokine. Significant TNFα release was observed with bevacizumab (P = 0.0001), trastuzumab (P = 0.0031) and alemtuzumab (P = 0.0177), but no significant IL-2 release. TGN1412 and muromonab-CD3 caused pro-inflammatory cytokine release despite significantly (both P < 0.0001) increasing numbers of T-cells with a regulatory phenotype.Conclusions The severity of the adverse response to TGN1412 compared with muromonab-CD3 and other therapeutic mAbs correlates with the level of IL-2 release.

Vi capsular polysaccharide (Vi) conjugate vaccines, which can prevent typhoid in infants and young children, are being developed. Comparative immunogenicity studies are facilitated by an International Standard (IS) for human anti-Vi IgG. 16/138, a pool of sera from volunteers which received either Vi conjugate vaccine or plain Vi vaccine, was assessed as an IS alongside U.S. reference reagent Vi-IgGR1, 2011. Samples were tested in a commercial ELISA (n = 7), a standardised ELISA based on biotinylated Vi (n = 7) and in-house ELISAs (n = 7). Valid estimates were obtained for the potency of all samples in the commercial ELISA, and the commutability of 16/138 and Vi-IgGR1, 2011 was evident for the commercial ELISA and in-house ELISAs based on a coating of Vi and protein. The WHO Expert Committee on Biological Standardization established 16/138 as the first IS for anti-Vi IgG with 100 IU per ampoule and assigned 163 IU per vial of Vi-IgGR1, 2011.

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As the latest addition to the sub-strain specific WHO Reference Reagents of BCG vaccine, an international collaborative study was completed to evaluate the suitability of a candidate BCG Moreau-RJ sub-strain as a WHO Reference Reagent of BCG vaccine. This follows the recent replacement of the WHO 1st International Reference Preparation for BCG vaccine, by three sub-strain specific WHO Reference Reagents of BCG vaccine (Danish 1331, Tokyo 172-1 and Russian BCG-I) in order to complete the coverage of most predominant sub-strains used for BCG vaccine production and distribution for use worldwide. The study used cultural viable count and modified ATP assays to quantify the preparation and multiplex PCR to confirm the identity of the sub-strain. The establishment of this WHO Reference Reagent of BCG vaccine of Moreau-RJ sub-strain was approved by the WHO Expert Committee on Biological Standardization meeting in October 2012. This preparation is available for distribution by NIBSC-MHRA, UK. The data from real-time stability monitoring demonstrated that these Reference Reagents of BCG vaccine are very stable in storage condition at −20 °C. They serve as the valuable source of BCG Reference Reagents for use as comparators (1) for viability assays (such as cultural viable count and modified ATP assays); (2) for in vivo assays (such as the absence of virulent mycobacteria, dermal reactivity and protection assays) in the evaluation of candidate TB vaccines in non-clinical models; (3) for identity assays using molecular biology techniques.