# Molecular Hydrogen Therapy Enhances Immune Markers in Treg, Plasma, Tr1 Cells, and KLRG1 Expression on Tc Cells: A Case of Acute SDH With Midline Shift and Uncal Herniation Post-decompressive Craniectomy.
> 急性硬膜下血腫（正中偏位・鉤ヘルニア）に対する減圧開頭術後における分子状水素投与と免疫マーカー変動：症例報告


## Abstract

Subdural hematoma (SDH) carries substantial mortality and long-term neurological sequelae. This case describes a 24-year-old male presenting with acute SDH accompanied by right-sided midline shift, uncal herniation, and left pupil dilation. Standard neurocritical interventions—decompressive craniectomy, hyperbaric oxygen, therapeutic hypothermia, and stem cell administration—were employed for stabilization. Hydrogen capsules were introduced as an adjunctive measure beginning on the day of admission. Immunological monitoring revealed increases in regulatory T cells (Treg), plasma cells, and Tr1 cells, as well as elevated KLRG1 expression on cytotoxic T cells, without any observed adverse events. Although neurological recovery was attributed primarily to conventional interventions, the immune marker changes observed during hydrogen administration suggest a potential immunomodulatory role. The authors conclude that further controlled investigation is warranted to clarify the contribution of molecular hydrogen in SDH management.

### Mechanism

Molecular hydrogen is proposed to exert neuroprotection by reducing oxidative stress, suppressing inflammatory signaling, inhibiting apoptosis, and preserving mitochondrial function. In this case, immunomodulatory effects were suggested by upregulation of Treg and Tr1 cell activity and increased KLRG1 expression on cytotoxic T cells.

## Bibliographic

- **Authors**: Hsu HF, Hu RY, Lu J, Hueng DY, Ho YJ, Lui SW, et al.
- **Journal**: In Vivo
- **Year**: 2025
- **PMID**: [40010997](https://pubmed.ncbi.nlm.nih.gov/40010997/)
- **DOI**: [10.21873/invivo.13923](https://doi.org/10.21873/invivo.13923)
- **PMC**: [PMC11884442](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11884442/)
- **Study type**: human case report
- **Delivery route**: hydrogen-rich water
- **Effect reported**: mixed

## Delivery context

Hydrogen-rich water is a low-risk delivery route, but the achievable systemic hydrogen dose is bounded. For clinical applications, inhalation is the most efficient route; inhalation, however, carries explosion risk, and concentration matters (empirical LFL of 10% applies to inhalation environments; high-concentration devices are documented in the Consumer Affairs Agency accident database and are not recommended).

## Safety notes

Hydrogen-rich water is a low-risk delivery route, but the achievable systemic hydrogen dose is bounded. For clinical applications, inhalation is the most efficient route; inhalation, however, carries explosion risk, and concentration matters (empirical LFL of 10% applies to inhalation environments; high-concentration devices are documented in the Consumer Affairs Agency accident database and are not recommended).

See also:
- [Inhalation concentration and LFL / UFL](https://h2-papers.org/en/safety-notes/inhalation-concentration)
- [Consumer Affairs Agency accident cases](https://h2-papers.org/en/safety-notes/accident-cases)
- [Inhalation safety threshold lineage](https://h2-papers.org/en/safety-notes/lineage)

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> **Cite as**: H2 Papers — PMID 40010997. https://h2-papers.org/en/papers/40010997
> **Source**: PubMed PMID [40010997](https://pubmed.ncbi.nlm.nih.gov/40010997/)