Development and validation of an ELISA-based assay for detecting anti-idursulfase beta IgE antibodies in human serum using a conjugated IgG-IgE positive control antibody.

Mutations in the Iduronate 2-sulfatase (IDS) gene cause Hunter syndrome (also known as mucopolysaccharidosis type II, or MPS II), a rare genetic condition that causes glycosaminoglycans (GAGs) to accumulate. Although enzyme replacement therapy (ERT) is the usual course of treatment, it can cause immunological reactions, such as the generation of IgE antibodies specific to the drug, which can result in hypersensitivity reactions. In this study, an ELISA-based test for characterizing anti-idursulfase beta IgE antibodies in human serum was developed and its analytical feasibility was validated. The complex challenges of generating antibodies against the IgE isotype using conventional methods make it difficult to generate an appropriate positive control antibody for IgE-specific tests. In order to overcome this difficulty, Anti-IDS IgG and Human IgE antibodies were chemically linked to generate IgG-IgE conjugate antibodies. Using this conjugated IgG-IgE positive control antibody, we developed the assay and validated it following immunogenicity guidelines, assessing validation parameters such as cut point, sensitivity, specificity, selectivity, precision, drug tolerance, and stability. The results demonstrate the methodological suitability of this assay for IgE isotype characterization.