1. Systemic T-cell activation and interferon-γ activity in indeterminate severe hepatitis (iSH) are reminiscent of hemophagocytic lymphohistiocytosis (HLH): Implications for T-cell and interferon-γ directed therapies.
- Author
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Nguyen TH, Satwani P, Kumar D, Kapoor U, Malik S, Prince C, Montminy T, Smiley K, Martinez M, Goldner D, Marsh R, Remotti HE, Fazlollahi L, Rytting HB, Romero R, and Chandrakasan S
- Abstract
Background: Severe hepatitis cases in children are increasingly recognized, however, the exact etiology remains unknown in a significant proportion of patients. Cases of indeterminate severe hepatitis (iSH) may progress to indeterminate pediatric acute liver failure (iPALF), hence understanding the immunobiology is critical to preventing disease progression. Hemophagocytic lymphohistiocytosis (HLH) is a systemic hyperinflammatory disorder associated with T-cell and macrophage activation with liver injury., Objectives: We hypothesized a high proportion of patients with iSH demonstrate systemic T-cell activation similar to HLH prior to developing iPALF and that the degree of T-cell activation in iSH might correlate with outcomes., Methods: From 2019-2022, 14 patients with iSH and 7 patients with PALF of known, non-immune etiology were prospectively enrolled. We compared immune signatures of iSH, HLH, known PALF, and healthy controls., Results: We found that patients with iSH have increased CD8
+ T-cell activation and high interferon-γ activity similar to HLH. The amplitude of CD8+ T-cell activation was predictive of iSH progression to iPALF. We also found that in patients with iSH, ferritin had only modest elevation. However, age-normalized plasma soluble interleukin-2 receptor (sIL-2R) to ferritin level ratio can distinguish iSH from known PALF and HLH. As a proof of concept, we report that in three patients with steroid refractory iSH, emapalumab, an IFN-γ blocking antibody used in combination with steroids, improved liver function and may have prevented progression to PALF., Conclusions: Our data suggests flow-based T-cell activation markers could help in early identification and risk stratification for targeted intervention in patients with iSH., (Copyright © 2024. Published by Elsevier Inc.)- Published
- 2024
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