530 - Standard Clinical Laboratory Measurements in Children with and without Long COVID: RECOVER Pediatric Cohort Study

Publication Number: 4518.530

Melissa Stockwell, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, United States; Heqiong Wang, Emory University School of Medicine, decatur, GA, United States; Stephanie W. Waldrop, Pennington Biomedical Research Center, Baton Rouge, LA, United States; Rachel S. Gross, New York University Grossman School of Medicine, New York, NY, United States; Laura Covington, RECOVER Representative, Fredericksburg, VA, United States; Alexia Debrosse, RTI, Rochester, MN, United States; Lia Evans, NIH RECOVER Long COVID Initiative, Los Angeles, CA, United States; Lydia Lerma, Hassenfeld Children's Hospital at NYU Langone, Fort Collins, CO, United States; Christine Maughan, RECOVER, Logan, UT, United States; Tsungirirai Maramba, Emory University School of Medicine, Atlanta, GA, United States; Katherine Irby, Arkansas Children's Research Institute/ UAMS, Little Rock, AR, United States; Lawrence C. Kleinman, Rutgers RWJMS, New Brunswick, NJ, United States; Kyung E.. Rhee, UC San Diego School of Medicine, LA JOLLA, CA, United States; Kelan Tantisira, Rady Children's Hospital San Diego, San Diego, CA, United States; Amy L. Salisbury, Virginia Commonwealth University, Richmond, VA, United States; Patricia Kinser, Virginia Commonwealth University School of Nursing, Richmond, VA, United States; John Wood, Childrens Hospital Los Angeles, Los Angeles, CA, United States; Thomas J. Connors, Columbia University Medical Center, New York, NY, United States; Qian Yang, Emory University, Atlanta, GA, United States; Jasmine Berry, Emory University School of Medicine, ATLANTA, GA, United States; Cyra Christina Mehta, Emory University, Atlanta, GA, United States; Sindhu Mohandas, Children's Hospital Los Angeles, Los Angeles, CA, United States

Background: Pediatric Long COVID (LC) is a chronic condition that may develop after SARS-CoV-2 infection. Symptoms can affect almost every organ, making diagnosis challenging. LC symptoms can emerge, persist, improve, or relapse over time. No validated clinical biomarkers exist to help with diagnosis; it remains unclear whether any standard clinical laboratory tests differ between children with and without LC.

Objective: Characterize clinical laboratory values by LC: 1) presence; 2) symptom trajectory (persistent, improved or incident/relapsing); 3) phenotypic symptom clusters.

Design/Methods: We conducted a prospective longitudinal analysis of school-age children (6-11) and adolescents (12-17 years) participating in the NIH-funded RECOVER national pediatric observational cohort. At enrollment and 6-month follow-up, families completed an extensive symptom survey to determine LC status using the published age-specific Pediatrics LC Research Index (LCRI), which differentiated those with and without LC from those never infected, as well as LC phenotypic clusters (e.g., predominated by GI symptoms). LC trajectories from enrollment to 6-month follow-up were categorized as persistent (LC at both timepoints), improved (LC at enrollment only) and incident/relapsing (LC at 6 months only). Outcomes included 39 clinical laboratory tests at 6-month follow-up (Table 1). Stratifying by age group doubly robust estimation method and propensity score were applied for each laboratory measurement to evaluate between-group differences in average effect by LC status, trajectory and phenotypic cluster.

Results: Overall, 1101 participants were analyzed, 327 who had LC at enrollment)(Table 2). LC trajectory from enrollment to 6 month-visit varied (209 persistent, 118 improved, 86 incident/relapsing, and 573 without LC at both timepoints). Those with LC were distributed across different phenotypic clusters at 6-month follow-up: multisystem (21 school-age; 108 adolescents), pain/fatigue (26 school-age; 63 adolescents), neurocognitive (44 school-age only), GI (19 school-age only), and loss taste/smell (14 adolescents only). No difference in any laboratory value was associated with LC status, trajectory, or phenotypic cluster.

Conclusion(s): No clinical laboratory test assessed was associated with or indicative of pediatric LC. While clinicians may use tests to assess other conditions that could mimic or co-occur with LC, LC remains a symptom-based diagnosis and cannot be confirmed using current standard clinical laboratory tests. Future studies should focus on identifying novel biomarkers beyond routine laboratory tests (e.g., proteomics).

Clinical Laboratory Measurements Assessed


Table 2: Study Population Characteristics