Gans, Melissa D.

Down syndrome (DS), the genetic condition caused by trisomy 21 (T21), is characterized by lifelong immune dysregulation leading to high rates of autoimmune disorders, elevated risk of complications from infections, immune hypersensitivity, and a unique form of immunodeficiency. It is now appreciated that DS shares key hallmarks with interferonopathies, with vast remodeling of all branches of the immune system, hypercytokinemia, and widespread autoantibody production. Here within, we review the existing literature with an emphasis on clinical considerations toward monitoring, management, and therapeutic opportunities. We highlight recent research advances that illuminate diagnostic approaches to evaluate immune dysregulation in DS. We also discuss the evidence supporting specific immunomodulatory strategies that could have multidimensional benefits in this population, including JAK inhibitors, intravenous immunoglobulin, and B cell–depleting agents.

Introduction Individuals with inborn errors of immunity (IEI) are increasingly reaching reproductive age, yet guidance on fertility preservation, genetic counseling, medication adjustments in pregnancy and breastfeeding, monitoring for complications, and multidisciplinary coordination is lacking. This joint effort between two committees of the Clinical Immunology Society (CIS), the Women of the Clinical Immunology Society (WCIS) and the Adult Immune Deficiency Committee (AID) survey aimed to characterize current reproductive care practices for IEI patients. Methods A survey was disseminated to 809 CIS members. The response rate was 6.43% (52 respondents). The 24-item questionnaire addressed management of pregnancy in IEI, medications adjustment, participation in hematopoietic stem cell transplant (HSCT) care and fertility preservation, and maternal/neonatal outcomes. Results Because survey items were optional, the number of respondents varies by question. Forty-two participants completed core items: 64% (27/42) allergists/immunologists, 71% (30/42) practicing at academic centers, and 48% (20/42) with >50% immunology-focused practices. Most respondents (78%, 41/52) currently or previously cared for pregnant/planning IEI patients. Preconception counseling was common (90%, 37/41), yet only 2% (1/41) have access to a formal reproductive multidisciplinary team. Among clinicians involved in HSCT care, 45% (13/29) referred patients for fertility preservation. More than half, 52% (22/42), observed reduced fertility in IEI patients, and 56% (20/36) observed adverse maternal outcomes. Medication management varied: 61% (24/39) discontinued known teratogenic medications, and 64% (25/39) adjusted dosing during pregnancy. Regarding immunoglobulin replacement therapy, 79% adjusted dosing based on IgG levels and 42% increased dosing by trimester. Conclusions This CIS survey reveals practice variability and notable gaps in reproductive health support for individuals with IEIs. Due to the relatively low response rate, generalizability across providers and practice settings is challenging. However, the results of this survey suggest that although most clinicians provide preconception counseling and manage IgG and immunomodulatory therapy during pregnancy, formal multidisciplinary structures are rare. High rates of reported fertility concerns and maternal complications underscore the need for enhanced collaboration with obstetrics/gynecology and the development of structured, evidence-based, multidisciplinary guidelines for reproductive care in IEI. Tabular data are included as downloadable supplement files.