- PMID: 30382050
Abstract
      
      It has been reported that PD-1-expressing CD8+ T cells in the 
peripheral blood of cancer patients are associated with poor cancer 
prognosis. In addition, these cells are in a state of energy shortage 
caused by mitochondrial dysfunction with a low level of PGC-1a. 
Recently, hydrogen gas was reported to activate PGC-1a, leading to the 
enhancement of mitochondrial activity. In the present study, we 
investigated whether hydrogen gas influences the proportion of PD-1+ 
CD8+ T cells in the peripheral blood of 55 Stage IV colorectal carcinoma
 patients. We found that the proportion of terminal PD-1+ CD8+ T cells 
was an independent factor for poor prognosis. We also found that the 
proportion of terminal PD-1+ CD8+ T cells was reduced in 35 out of 55 
patients(63.6%)and was increased in 39 out of 55 patients(70.9%)after 
treatment with hydrogen gas. The ratio of the terminal PD-1+ CD8+ T 
cells after hydrogen gas treatment to that before hydrogen gas 
treatment(terminal PD-1+ CD8+ T cell ratio)was found to be an 
independent factor predicting PFS and OS. Out of another 26 patients 
treated with nivolumab, 14 patients treated with a combined therapy of 
hydrogen gas and nivolumab showed a significantly longer OS than the 
remaining 12 patients who were treated with nivolumab alone. These 
results suggest that hydrogen gas improves the prognosis of cancer 
patients by reducing the proportion of terminal PD-1+ CD8+ T cells.
Source: https://pubmed.ncbi.nlm.nih.gov/30382050/