The monoclonal antibody (mouse IgG1-isotype) was produced in hybridoma cells by standard techniques

The monoclonal antibody (mouse IgG1-isotype) was produced in hybridoma cells by standard techniques. 4.1. ferric carboxymaltose, as well as isomaltoside 1000, the isolated carbohydrate component of iron isomaltoside 1000. Low molecular weight iron dextran, as MC-976 well as dextran-based ferumoxytol and iron isomaltoside 1000, reacted MC-976 with 5E7H3, whereas ferric carboxymaltose, iron sucrose, sodium ferric gluconate, and isolated isomaltoside 1000 did not. Consistent results were obtained with reverse single radial immunodiffusion assay. The results strongly support the hypothesis that, while the carbohydrate alone (isomaltoside 1000) does not form immune complexes with anti-dextran antibodies, iron isomaltoside 1000 complex reacts with anti-dextran antibodies by forming multivalent immune complexes. Moreover, non-dextran based preparations, such as iron sucrose and ferric carboxymaltose, do not react with anti-dextran antibodies. This assay allows to assess the theoretical possibility of a material to induce antibody-mediated DIARs. Nevertheless, as this is only one possible mechanism that may cause a hypersensitivity reaction, a broader set of assays will be required to get an understanding of the mechanisms that may lead to intravenous iron-induced hypersensitivity reactions. strong class=”kwd-title” Keywords: anaphylaxis, antidextran, intravenous iron 1. Introduction Iron is an essential component of the body. However, when present in excess, iron is usually toxic [1] and has the potential to induce oxidative stress [2]. Thus, iron levels are under tight control: Iron uptake via the duodenum is usually strictly regulated, resulting in only small amounts of iron to be assimilated daily [3]. Intravenous (IV) iron therapy is used to treat iron deficiency (ID) and iron deficiency anemia (IDA), when there is a need for fast replenishment or when oral iron is ineffective or not tolerated [4]. Because IV administration bypasses the strictly regulated iron absorption in the gut, it is critical that IV iron preparations are engineered to deliver high doses of iron in a stable, non-reactive and non-toxic form. All preparations for IV iron therapy are composed of carbohydrate-stabilized polynuclear iron(III)-oxyhydroxide/oxide nanoparticles formulated as colloidal solutions. Thus, they are non-biological complex drugs (NBCDs) [5,6]. The carbohydrate shell is unique for each preparation. In addition to stabilizing the iron core in a ligand-specific way, the shell is the key component regulating the stability, size, shape and surface charge of the iron-carbohydrate Rabbit Polyclonal to ADA2L complex [2]. Thus, upon IV administration, the carbohydrate shell determines the metabolic pathway of the complexes, affecting their pharmacokinetics and pharmacodynamics, as well as their conversation with the innate immune system and, thus, side effects [2]. Current IV iron preparations on the market in Europe and/or in the US include iron sucrose (Is usually), ferric carboxymaltose (FCM), sodium ferric gluconate (SFG), iron isomaltoside 1000 (IIM), ferumoxytol (FMX), and low molecular weight iron dextran (LMWID). Depending on the type of the carbohydrate shell, these preparations can be classified as (a) non-dextran-based and (b) dextran/dextran-based complexes [7]. Non-dextran-based complexes exhibit a correlation between molecular weight distribution and complex stability, i.e., complexes with higher molecular weight are more stable and have lower labile iron content than complexes with lower molecular weight [8,9]. In contrast, dextran/dextran-based complexes are all very stable impartial of their molecular weight [1,8,9]. A previous reverse single radial immunodiffusion assay exhibited that MC-976 LMWID, FMX and IIM reacted with an anti-dextran antibody, whereas Is usually, SFG and FCM did not [10]. However, as this methodology was criticized [11], a new monoclonal anti-dextran antibody (mouse IgG-isotype) and an enzyme-linked immunosorbent assay (ELISA) were developed [12]. As intravenous dextran can cause severe, antibody-mediated dextran-induced anaphylactic reactions (DIARs), the purpose of this study was to assess the overall possibility of a complex formation with anti-dextran antibodies of the different non-dextran-based or dextran/dextran-based IV iron preparations as well as of the isolated carbohydrate components. The results strongly support the hypothesis that, while the carbohydrate alone (isomaltoside 1000, IM1000) does not form immune complexes with anti-dextran antibodies, iron isomaltoside 1000 complex reacts with anti-dextran antibodies by forming multivalent immune complexes. Moreover, non-dextran based preparations, such as iron sucrose and ferric carboxymaltose, do not react with anti-dextran antibodies. 2. Results In the newly developed ELISA assay, a positive result was defined as A450 ratio (sample/blank) 2.1. The results against the antigen used for antibody production (dextran 50,000) resulted in a titer of 1:81,000, i.e., 12.3 ng/mL gave a positive reaction. Two individual ELISA experiments were carried out. In the first, the six different IV iron preparations were assessed and in the second, IIM was reassessed together with its carbohydrate component IM1000. MC-976 Positive reactions against 5E7H3 were observed for FMX, IIM, LMWID, and dextran 5000 (positive control) (Table 1 and.