301 - Examining Hospitalization Rates in Trisomy 21: Who, What, and When Should Prompt Immune Evaluation

Publication Number: 2291.301

Emily M. Downs, Medical University of South Carolina College of Medicine, Charleston, SC, United States; Anna Grace Chang, Medical University of South Carolina College of Medicine, Charleston, SC, United States; Natalie Eidson, University of Virginia, Charlottesville, VA, United States; Macoy Pitts, Medical University of South Carolina College of Medicine, Charleston, SC, United States; Emily Campbell, Medical University of South Carolina College of Medicine, Charleston, SC, United States; Kelli W. Williams, Medical University of South Carolina College of Medicine, Charleston, SC, United States

Background: Patients with Trisomy 21 (T21) have higher rates of both infections and immune deficiency. While not all children with T21 will have immune deficiency, prompt recognition and referral for immune evaluation may decrease morbidity and mortality, decrease healthcare utilization, and improve quality of life.

Objective: Describe hospitalization rates in children with T21 with and without immunodeficiency and assess if there is a hospitalization count at which an immune evaluation should be initiated.

Design/Methods: Retrospective chart review of patients ≤ 18 years of age with T21 at a single quaternary academic center was conducted from August 2023-November 2024. Patients with T21 were identified in the electronic medical record. Demographic, laboratory and hospitalization details were collected. Hospitalizations were categorized based on reason for admission and stratified between those with and without confirmed immunodeficiency. Descriptive statistics were calculated, and t-tests were used to assess variables with significance set at p < 0.05. Sensitivity, specificity, and predictive values were calculated for various variables and cutoffs to assess for predictors of immunodeficiency.

Results: 399 patients with T21 had a cumulative 1445 admissions and 5,386 cumulative days of admission. 14 patients (3.5%) had confirmed immunodeficiency, including anti-pneumococcal polysaccharide antibody deficiency (50%), multiple immune abnormalities (36%), and IgM deficiency (14%). Individuals with T21 and immunodeficiency had significantly more admissions (mean of 12.1 vs. 3.3, p=0.006) and more cumulative days admitted (mean 35.8 days vs. 12.7 days, p=0.10 ) compared to their counterparts without confirmed immunodeficiency. Those with immunodeficiency also had a higher percentage of respiratory-related admissions (19.4% versus 18.1%, p=0.049). More than 8 hospital admissions yielded a positive predictive value for immunodeficiency of 22.6%, with 50% sensitivity and 93.8% specificity. More than 3 admissions for respiratory concerns also yielded a positive predictive value of 21.1% with sensitivity of 28.6% and specificity of 96.1%. Number of ICU admissions, total hospitalization days, and total respiratory-related hospitalization days were comparable between groups.

Conclusion(s): Patients with T21 with immunodeficiency are hospitalized more frequently overall and specifically for respiratory conditions. As such, pediatric providers, especially hospitalists, should have a low threshold for immunology referral in patients with T21.