Scientific report 2024 of the Inborn Errors Working Party (IEWP)

The year 2024 has been another pivotal year for the Inborn Errors Working Party (IEWP) of the EBMT, marked by groundbreaking studies and collaborative achievements in the field of hematopoietic stem cell transplantation (HSCT) for Inborn Error of Immunity (IEI) and non-malignant genetic disorders.

Several key studies have been published. The retrospective analysis of HLA-mismatched HSCT with TCRαβ/CD19 depletion or post-transplant cyclophosphamide (Blood) provides valuable insights into these approaches applied to IEI. Other studies investigated HSCT outcomes for CTLA-4 insufficiency (J Allergy Clin Immunol), ICF syndrome (J Clin Immunol), JAGN1 severe congenital neutropenia (Blood Advances) and C1q deficiency (J Clin Immunol)) and have significantly expanded the understanding of transplant strategies in these rare conditions. Another notable publication, in Blood Advances, focused on permissible HLA mismatches in 9/10 HLA-matched pediatric HSCT using the HLA-EMMA approach, paving the way for improved donor selection practices in pediatric patients.

Moreover, important ongoing studies continue to shape the landscape of HSCT for inborn errors of immunity, including research on FHL2 and FHL3, and long-term outcomes in Chediak-Higashi syndrome, and osteopetrosis. 

In terms of educational initiatives, the second IEWP Spring School on HSCT in Inborn Errors of Immunity, held in Montserrat, Spain in June 2024, brought together over 30 international experts and attendees to deepen knowledge and share expertise on cellular therapies in these disorders. This event follows the success of the inaugural edition in 2023 at Frauenchiemsee, Germany.

The IEWP continues to push the boundaries of scientific knowledge and clinical practice, fostering collaboration across Europe and intercontinental to improve patient outcomes and refine transplant protocols.