Hydrogen Gas Fails to Protect Kidneys from Transplant Damage in Pig Study
- Authors
- Sarah A. Hosgood, Tom Moore, Maria Qurashi, Tom Adams, Michael L. Nicholson
- Journal
- Artificial Organs
- Year
- 2018
- DOI
- 10.1111/aor.13118
- Study Type
- Pig
- Outcome
- Neutral
- Peer Reviewed
- Yes
- Country
- United Kingdom
- Health Condition
- Kidney Transplant Rejection
- Body System
- Renal
TL;DR
Adding hydrogen gas to the blood used to reperfuse damaged kidneys in a pig model did not improve kidney function or decrease damage and inflammation.
Key Finding
Hydrogen gas administered during reperfusion did not improve kidney function, reduce oxidative damage, or decrease inflammation in pig kidneys recovering from ischemia reperfusion injury.
Summary
Researchers tested whether hydrogen gas could protect pig kidneys from damage that occurs when blood flow is cut off and then restored—a common problem in kidney transplants. Kidneys were deprived of oxygen for extended periods, then reperfused (blood flow restored) with or without hydrogen gas added to the blood supply. Despite hydrogen's known ability to reduce inflammation and oxidative stress (cellular damage from unstable molecules), the hydrogen treatment did not improve kidney function, reduce markers of damage, or lower inflammatory chemicals compared to the control group.
Practical Takeaway
This preclinical study in pigs found no benefit of hydrogen gas for protecting transplanted kidneys from ischemia reperfusion injury, which contradicts the theoretical promise of hydrogen's antioxidant properties. However, this is a single animal study with a small sample size, so it does not rule out hydrogen's potential in other contexts or in human transplantation. More research would be needed to understand why hydrogen did not work in this specific model.
Abstract
In renal transplantation, ischemia reperfusion injury impairs early graft function and can reduce long term graft survival. Hydrogen has antioxidant and anti‐inflammatory properties that can reduce the effects of ischemic injury. The aim of this study was to examine the effects of hydrogen gas administered during reperfusion in a preclinical model of kidney ischemia reperfusion injury. Porcine kidneys underwent 15 min of warm ischemia followed by 22 h of cold ischemia. They were then reperfused for 6 h with whole autologous blood on an ex vivo reperfusion circuit. Paired kidneys were randomized to control (n = 6) (25% oxygen, 5% carbon dioxide, 70% nitrogen) or hydrogen (n = 6) (2% hydrogen, 25% oxygen, 5% carbon dioxide, 68% nitrogen) groups. Tissue, urine, and blood samples were collected at baseline and hourly throughout the reperfusion period. Baseline measurements were similar across groups. Following perfusion, there was no significant difference between control and hydrogen groups in urine output (693 mL vs. 608 mL, P = 0.86), renal blood flow (105.9 vs. 108 mL/min/100g, P = 0.89), acid‐base homeostasis, or creatinine clearance. There was a significant increase in cytokine levels from baseline to 6 h in both groups (IL‐1β P = 0.002; IL‐6 P = 0.004; IL‐8 P = 0.002). However, there were no significant differences in levels of inflammatory cytokines (IL1β, IL‐6, and IL‐8) between the groups. The administration of hydrogen gas did not improve renal function, reduce oxidative damage, or inflammation during the reperfusion of ischemically damaged kidneys.