New primary immunodeficiencies 2023 update

Purpose of review Primary immunodeficiency diseases (PIDs), also called inborn errors of immunity (IEI), are genetic disorders characterized by increased susceptibility to infection and/or aberrant regulation of immunological pathways. This review summarizes and highlights the new IEI disorders in the International Union of Immunological Societies (IUIS) 2022 report and current trends among new PIDs. Recent findings Since the 2019 IUIS report and the 2021 IUIS interim update, the IUIS IEI classification now includes 485 validated IEIs. Increasing utilization of genetic testing and advances in the strategic evaluation of genetic variants has continued to drive the identification of, not only novel IEI disorders, but additional genetic etiologies for known IEI disorders and phenotypes. Summary The recognition of new IEIs continues to advance at a rapid pace, which is due in part to increased performance and application of genetic modalities as well as expansion of the underlying science that is applied to convincingly establish causality. These disorders, as a whole, continue to emphasize the specificity of immunity, complexity of immune mechanisms, and the fine balance that defines immune homeostasis.