Molecular Hydrogen as a Promising Therapy Could Be Linked With Increased Resting Treg Cells or Decreased Fas+ T Cell Subsets in a IgG4-PF-ILD Patient: A Case Report.
IgG4関連進行性線維化間質性肺疾患患者における水素吸入後の制御性T細胞増加およびFas陽性T細胞サブセット減少：症例報告
Abstract
An 85-year-old female with suspected IgG4-related progressive fibrosing interstitial lung disease (PF-ILD) complicated by hospital-acquired pneumonia received molecular hydrogen inhalation. By the fourth day, chest X-ray imaging revealed a reduction in pulmonary infiltrations, and the patient began progressing toward mechanical ventilation weaning. Immune phenotyping conducted before and after hydrogen exposure showed a marked elevation in resting regulatory T cell (Treg) counts alongside a substantial decline in Fas-positive helper T cell and cytotoxic T cell subsets. These immunological shifts suggest that molecular hydrogen may modulate immune responses in PF-ILD through anti-inflammatory and antioxidant mechanisms, warranting further investigation in larger patient cohorts.
Mechanism
Molecular hydrogen is proposed to exert anti-inflammatory and antioxidant effects that upregulate resting regulatory T cells while downregulating Fas-positive helper and cytotoxic T cell subsets, thereby modulating immune-mediated pulmonary fibrosis.
Bibliographic
- Authors
- Lui SW, Lu J, Ho YJ, Tang SE, Ko KH, Hsieh TY, et al.
- Journal
- In Vivo
- Year
- 2024
- PMID
- 38688598
- DOI
- 10.21873/invivo.13600
- PMC
- PMC11059909
Tags
Delivery context
In air, molecular hydrogen is reported to be combustible across approximately **4% (LFL, lower flammability limit) to 75% (UFL, upper flammability limit)**. Among high-concentration hydrogen inhalers, 66% output sits inside this range, and even pure-hydrogen (100%) output forms a 4–75% concentration-gradient layer at the device–air boundary (the UFL 75% paradox). Engineering principle would therefore call for operation below LFL (the classical 4%); that figure, however, was measured under closed, pre-mixed, static conditions. For the open, dynamic inhalation environment, the empirical value reported in the literature is **10%**, which is the figure referenced in practice as the operating ceiling. The 66% / 100% output devices are recorded in the Japanese Consumer Affairs Agency accident-information database, and from these considerations are not recommended.
Safety notes
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