OrganLife Laboratory, Department of Visceral, Transplant and Thoracic Surgery, Medical University of Innsbruck, Innsbruck, Austria.
Institute of Pathology, Neuropathology and Molecular Pathology, Medical University of Innsbruck, Innsbruck, Austria.
Transpl Int. 2024 May 23;37:12787. doi: 10.3389/ti.2024.12787. eCollection 2024.
Organ quality can be assessed prior to transplantation, during normothermic machine perfusion (NMP) of the liver. Evaluation of mitochondrial function by high-resolution respirometry (HRR) may serve as a viability assessment concept in this setting. Freshly collected tissue is considered as optimal sample for HRR, but due to technical and personnel requirements, more flexible and schedulable measurements are needed. However, the impact of cold storage following NMP before processing biopsy samples for mitochondrial analysis remains unknown. We aimed at establishing an appropriate storage protocol of liver biopsies for HRR. Wedge biopsies of 5 human livers during NMP were obtained and assessed by HRR. Analysis was performed after 0, 4, 8, and 12 h of hypothermic storage (HTS) in HTK organ preservation solution at 4°C. With HTS up to 4 h, mitochondrial performance did not decrease in HTS samples compared with 0 h (OXPHOS, 44.62 [34.75-60.15] pmol·s·mg wet mass vs 43.73 [40.69-57.71], median [IQR], > 0.999). However, at HTS beyond 4 h, mitochondrial respiration decreased. We conclude that HTS can be safely applied for extending the biopsy measurement window for up to 4 h to determine organ quality, but also that human liver respiration degrades beyond 4 h HTS following NMP.
在常温机器灌注（NMP）期间，可以在移植前评估器官质量。高分辨率呼吸测定法（HRR）评估线粒体功能可作为该环境下的生存能力评估概念。新鲜采集的组织被认为是 HRR 的最佳样本，但由于技术和人员要求，需要更灵活和可安排的测量。然而，在处理用于线粒体分析的活检样本之前，NMP 后的冷储存对其的影响尚不清楚。我们旨在为 HRR 建立肝活检的适当储存方案。在 NMP 期间，从 5 个人肝中获得楔形活检，并通过 HRR 进行评估。在 4°C 的 HTK 器官保存液中进行 4、8 和 12 小时的低温储存（HTS）后，对其进行分析。在 HTS 至 4 小时内，HTS 样本中的线粒体性能与 0 小时相比没有下降（OXPHOS，44.62 [34.75-60.15] pmol·s·mg 湿重与 43.73 [40.69-57.71]，中位数 [IQR]， > 0.999）。然而，在 HTS 超过 4 小时后，线粒体呼吸减少。我们得出结论，HTS 可安全地用于将活检测量窗口扩展至 4 小时，以确定器官质量，但 NMP 后，HTS 超过 4 小时也会导致人类肝脏呼吸功能下降。
