Prevention of Chronic Rejection of Marginal Kidney Graft by Using a Hydrogen Gas-Containing Preservation Solution and Adequate Immunosuppression in a Miniature Pig Model
Nishi K, Iwai S, Tajima K, Okano S, Sano M, Kobayashi E. · Frontiers in Immunology. 2021;11:626295.
Study at a glance
Preclinical
Four donor and eight recipient microminiature pigs; ischemic kidneys were transplanted across non-matched swine-leukocyte-antigen backgrounds with multidrug immunosuppression.
Donor kidneys were rinsed for ten minutes and stored for 60 or 240 minutes at 4°C in hydrogenated ETK preservation solution before transplantation. · Dissolved H₂ was maintained at at least 1 ppm for four hours. The preparation paragraph prints an internal container-pressure value of '0.06 ppm', which is dimensionally inconsistent and is preserved as a source issue rather than corrected by inference.
Ten-minute rinse, 60 or 240 minutes of cold storage, then follow-up to 100 days or humane endpoint.
Three of four hydrogenated-solution recipients reached 100 days; the fourth had major ureteral obstruction/intervention. All three non-hydrogenated ischemic-kidney recipients were sacrificed on days 3–7 with anuria, thrombosis and worsening kidney function. Long-term H₂ grafts had absent or mild chronic rejection, but the comparison was extremely small and not balanced for all surgical details.
Only four treated and three ischemic controls, one living reference, unknown SLA haplotypes, surgical/ischemic heterogeneity, major ureteral complication, extensive immunosuppression and limited mechanistic tissue assays. Doctors Man funded the work and helped devise the H₂-infusion system; two authors were medical advisers to the company.
What kind of evidence is this?
Preclinical
Controlled donor-after-cardiac-death kidney-transplant study in mature microminiature pigs
Kidney and urinary health
Other forms
Information not yet classified
Some editorial classification fields are still pending. The source-reported outcomes and result are shown below; Hydrogenology does not infer a positive or negative signal from prose automatically.
Methods
Four donor and eight recipient microminiature pigs; ischemic kidneys were transplanted across non-matched swine-leukocyte-antigen backgrounds with multidrug immunosuppression.
12 pigs overall. Recipient groups were hydrogenated preservation solution n=4, non-hydrogenated solution n=3 and one living-donor reference recipient n=1.
Ten-minute rinse, 60 or 240 minutes of cold storage, then follow-up to 100 days or humane endpoint.
Donor kidneys were rinsed for ten minutes and stored for 60 or 240 minutes at 4°C in hydrogenated ETK preservation solution before transplantation.
H₂ dissolved in organ-preservation solution — H₂ only, not Brown's gas and not inhalation.
Dissolved H₂ was maintained at at least 1 ppm for four hours. The preparation paragraph prints an internal container-pressure value of '0.06 ppm', which is dimensionally inconsistent and is preserved as a source issue rather than corrected by inference.
Non-hydrogenated ETK after the same 20-minute donor ischemia, plus one living-donor reference kidney.
Outcomes and reported result
Survival, urine output, BUN/creatinine, renal blood flow and resistive index, CT perfusion, thrombosis, histopathology, chronic rejection/fibrosis and syndecan-1.
Three of four hydrogenated-solution recipients reached 100 days; the fourth had major ureteral obstruction/intervention. All three non-hydrogenated ischemic-kidney recipients were sacrificed on days 3–7 with anuria, thrombosis and worsening kidney function. Long-term H₂ grafts had absent or mild chronic rejection, but the comparison was extremely small and not balanced for all surgical details.
The complete free PMC article, tables and supplement descriptions were checked for donor/recipient counts, preparation concentration, the printed unit inconsistency, storage schedules, survival and graft findings, complications, limitations, commercial funding and conflicts.
A reported association, difference or mechanism is not automatically a clinical benefit.
Limitations and applicability
Only four treated and three ischemic controls, one living reference, unknown SLA haplotypes, surgical/ischemic heterogeneity, major ureteral complication, extensive immunosuppression and limited mechanistic tissue assays. Doctors Man funded the work and helped devise the H₂-infusion system; two authors were medical advisers to the company.
Experimental marginal-kidney transplantation in mature miniature pigs; it does not establish human graft preservation or rejection prevention.
No single-study GRADE certainty rating is assigned. Read how records and evidence assessments are prepared.
Sources and record status
PMID: 33679720 · DOI: 10.3389/fimmu.2020.626295
Free full article in PubMed Central.
Complete PMC article, supplementary descriptions and PubMed metadata; full-text extraction checked 9 August 2026.
10 August 2026
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