Assessment of CD38brightHLA-DR+ T cells using a rapid flow cytometry-based assay to aid in the diagnosis of hemophagocytic lymphohistiocytosis and immune regulatory disorders in adult subjects

• Published in: Clinical immunology communications Vol. 8; pp. 1 - 5
• Main Authors: Khanolkar, Aaruni, Weyers, Erin, Sompallae, Ramakrishna, Krasowski, Matthew D.
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.12.2025; Elsevier
• Subjects: Adult-subjects; Ferritin; Flow cytometry; HLH; sIL-2R alpha; T cells; Flow cytometry; sIL-2R alpha; Adult-subjects; T cells; HLH; Ferritin
• ISSN: 2772-6134; 2772-6134
• DOI: 10.1016/j.clicom.2025.05.004

•There is a growing need to establish clinically-validated, rapid flow cytometry assays to aid in the diagnosis and management of hyperinflammatory disorders such as hemophagocytic lymphohistiocytosis (HLH).•The publications on this front have so far focused on pediatric age group patients.•In this study we evaluated the performance of a rapid, clinical flow cytometry test in adult and elderly patients suspected of suffering from HLH, against the gold standard measurements of soluble IL-2 receptor alpha (sIL-2Rα) and plasma ferritin.•Published evidence stretching back over three decades demonstrates that the CD38brightHLA-DR+ signature associated with activated T cells is not specific for HLH and/or disorders of immuneregulation.•Additional studies are needed to identify more specific markers in adult, elderly and pediatric subjects suspected of suffering from hyperinflammatory disorders such as HLH. Rapid and accurate diagnosis of patients suspected of suffering from hyperinflammatory conditions such as hemophagocytic lymphohistiocytosis (HLH) is a critical aspect of timely management for such disorders. Soluble IL-2Rα (sIL-2Rα) and plasma ferritin constitute the mainstay of frontline laboratory investigations performed to establish a clinical diagnosis for these patients. However, there is a paucity of clinical laboratories that perform the sIL-2Rα measurement as a stat test which can delay the diagnosis and management of these patients. Consequently, rapid flow cytometry-based tests that measure T cell activation are currently being evaluated. Previous studies have examined the utility of flow-cytometry based testing in pediatric subjects with HLH and immune dysregulation disorders. In this report, we assessed the utility of our flow-cytometry based test in adult patients suspected of HLH and discuss its performance in relation to what has been reported previously in the literature for pediatric patients.