The latest medical research on Transplant

The cost and complexity associated with animal testing are significantly reduced by using mock circulatory loops prior. Novel mock circulatory loops allow us to test biomedical devices preclinically due to their flexibility, scalability, and cost-effectiveness. The presented work describes the development of a hardware-in-the-loop platform to emulate human physiology for the Istanbul Heart (iHeart-II) LVAD.

A closed-loop system is developed whereby the effect of the LVAD on the heart and vice versa can be studied. An acausal model of the cardiovascular system is calibrated to emulate advanced-stage heart failure. A new prototype of the iHeart-II LVAD is connected between two air-actuated chambers emulating the left ventricle and aortic chambers with PID controllers tracking numerically modeled pressures from the in silico model. A lead-lag compensator is used to maintain fluid level. Controllers are tuned using nonlinear Hammerstein-Weiner models identified using open-loop data. The iHeart-II LVAD is operated at various speeds in its operational range, and the resulting hemodynamics are visualized in real time.

Hemodynamic variables, such as LVAD flow rate, aortic, left ventricular, and pulse pressure, demonstrate trends similar to clinical observations. The iHeart-II LVAD achieves hemodynamic normalization at ~3500 rpm for the emulated condition.

A novel evaluation methodology is adopted to study the performance of the iHeart LVAD under advanced-stage heart failure emulation. The models and controllers used in the platform are readily replicable to facilitate VAD research, pedagogy, design, and development.

The interleukin 1 (IL-1) cytokine group plays a key role in sterile inflammation and may be an important target for transplant-related renal injury. This study examined the effects of anakinra, a non-specific IL-1 receptor antagonist, administered during normothermic machine perfusion (NMP) of porcine kidneys.

Paired porcine kidneys (n = 5 pairs) underwent 15 min of warm ischemia plus 2 h of static cold storage in ice. Kidneys were then perfused with autologous whole blood using an ex vivo NMP platform. Kidneys were randomly allocated to receive anakinra or vehicle administered at the start of NMP. Cortical biopsies were collected at baseline before ischemic injury and at the end of NMP. Functional parameters were recorded and calculated, and inflammatory markers were measured by qPCR and ELISA techniques.

During NMP, there were no statistically significant differences in renal blood flow, urine output, creatinine clearance or fractional excretion of sodium in the anakinra and control groups. The administration of anakinra significantly downregulated transcriptional expression of IL-6, Fas ligand and intercellular adhesion molecule 1 (p = 0.029, 0.029, 0.028, respectively).

Anakinra, an IL-1 receptor blocker, successfully attenuated the downstream inflammatory and immune-mediated response within the kidney during NMP.

Tracheal decellularization is one of the main processes to provide tracheal substitutes for tracheal replacement. Recently, studies have been held for agents and combinations of processes for tracheal decellularization with different outcomes. This study aimed to evaluate the efficacy of tracheal decellularization by the immunogenic cellular elements using residual deoxyribonucleic acid (DNA) contents (ng/mg) and the preservation of biomechanical integrity by glycosaminoglycan (GAG) content (μg/mg), modulus tensile strength (MPa), ultimate tensile strength (MPa), and stress loading of 50% deformation (N).

We conducted a meta-analysis based on PRISMA criteria. Data from experimental studies in MEDLINE, Scopus, and ScienceDirect from inception to August 21, 2023, were sought and computed using RevMan 5.4. The outcomes of tracheal decellularization were evaluated through effect size estimates based on pooled Standardized Mean Difference (SMD) with 95% CI.

Tracheal decellularization has significantly reduced the DNA and GAG content after the process (SMD: -11.77, 95% CI [-13.92, -8.62], p < 0.00001; SMD: -6.70, 95% CI [-9.55, -3.85], p < 0.00001). No significant outcomes were observed in modulus and ultimate tensile strength result (SMD: -0.14, 95% CI [-0.64, 0.36], p = 0.58; SMD: 0.11, 95% CI [-0.57, 0.80], p = 0.75). The stress loading of 50% deformation was observed to significantly lower (SMD: -1.61, 95% CI [-2.49, -0.72], p = 0.0004).

Tracheal decellularization has been proven to effectively remove immunogenic cells. However, extracellular matrix integrity and biomechanical properties vary among different decellularization techniques, indicating a need for further refinement to achieve better preservation.

Adenovirus (ADV) infection can lead to significant morbidity and mortality in immunocompromised patients, particularly in those with hematopoietic stem cells or solid organ transplants. The incidence of ADV infection in kidney transplant (KT) is not well-defined as ADV is often asymptomatic and not routinely checked.

This retrospective case-series study included KT and simultaneous pancreas-KT (SPKT) recipients from January 1, 2008, to January 31, 2024, across three Mayo Clinic sites (Arizona, Florida, and Minnesota) with symptomatic adenovirus polymerase chain reaction cases. The primary outcomes were allograft function at various intervals post-ADV infection, allograft, and patient survival.

We report one of the largest multi-site case series regarding outcomes of ADV in KT with 17 patients. The median time to ADV infection was 30 weeks (5-74). Five patients (29%) developed disseminated infection. Nine patients (53%) of the entire cohort experienced graft loss within a median of 35 (4-168) weeks, with four (44%) of graft loss attributed to ADV. Nine patients (53%) developed rejections post-ADV infection with a median of 4 (2-8) weeks after resolution. One patient died from acute hypoxic respiratory failure from ADV infection.

ADV should be considered in KT/SPKT patients with renal dysfunction, hematuria, and with or without fever. Despite the low mortality rate, there is a significant risk of graft loss and rejection after ADV infection. It is crucial to screen for ADV and develop intervention strategies for treatment. Further multicenter studies are needed to better define, stage, and manage ADV infection.