Intestinal Graft Research Articles

Late graft loss after intestinal transplantation.

Despite improvement in short-term outcomes after intestinal transplantation in the last 20 years, long-term rates of graft attrition and patient survival remain unchanged, with worse outcomes compared with other solid organ transplants. This review investigates the multiple causes of late graft loss, including chronic rejection, infection, graft-versus-host disease, posttransplant lymphoproliferative disorder and postsurgical complications. New insights into immunology of the intestine and evolution of immunosuppression, as well as review of current persistent causes of late graft loss, shed light on findings that may help improve long-term intestinal allograft survival. Although intestinal transplantation remains a life-saving intervention with significant advancements since its inception, further understanding of mechanisms of injury is needed to improve long-term outcomes and prevent late intestinal graft loss.

Donor-specific antibody and sensitized patients in intestinal transplantation.

It has been well established that antibody to donor HLA pretransplant and the development of anti-human leukocyte antigen (HLA) antibodies posttransplant contribute to inferior graft survival outcomes. This article serves to review the current status of the management of pretransplant sensitized intestinal transplant candidate as well as to review posttransplant care of patients that harbor antidonor HLA antibodies. The intestinal transplant candidate oftentimes presents for transplant listing with high levels of anti-HLA antibodies that necessitate a careful preoperative strategy to avoid a donor-recipient pair that would result in a positive crossmatch. In the end, donor intestine offer acceptance is based on a balance between recipient clinical needs and allowable immunologic risk tolerance. The use of virtual crossmatching (VXM) enables the transplant center to effectively gauge the immunologic risk of each potential donor-recipient pair far in advance of allocating resources toward pursuing a donor organ. In those candidates with high levels of preformed donor anti-HLA antibodies, desensitization with a novel technique of donor splenic perfusion has been described as well as a single-center experience with a conventional desensitizing protocol. Posttransplant, with the use of a denovo donor-specific antibody (dnDSA) monitoring and treatment protocol, the well known deleterious effects of dnDSA can potentially be ameliorated, thus improving outcome. Efforts to establish a formal histologic criteria for antibody-mediated rejection (ABMR) in the intestinal graft continues to evolve with recent findings describing the relationship between DSA and histopathologic findings. Techniques such as the use of VXM, novel desensitization methods and protocols, monitoring and eradicating dnDSA, along with establishing new criteria for ABMR have all contributed to improving the outcomes in transplanting the immunologically challenging intestine.

Luminal polyethylene glycol solution delays the onset of preservation injury in the human intestine.

The organ damage incurred during the cold storage (CS) of intestinal grafts has short and long-term consequences. Animal studies suggest that additional luminal preservation (LP) with polyethylene glycol (PEG) may alleviate this damage. This study aims to validate these findings using human intestines. Ileal segments, perfused intravascularly with IGL-1 solution, were procured from 32 multiorgan donors and divided into two parts: one containing a PEG 3350-based solution introduced luminally (LP group) and another one without luminal treatment (control). Sampling was performed after 4h, 8h, 14h, and 24h of CS. Histology was assessed using the Chiu/Park score. Tight junctions (TJ), several inflammatory markers, and transcription factors were examined by immunofluorescence, ddPCR, and western blot. Tissue water content (edema) was also measured. Apoptotic activity was assessed with caspase -2, -3, and -9 assays. LP significantly lowered mucosal injury at all time points. Redistribution of TJ proteins occurred earlier and more severely in the control group. After 24h of CS, LP intestines showed an emerging unfolding protein response. Increased caspase-3 and -9 activity was found in the control group. The current results indicate that luminal PEG is safe and effective in reducing damage to the intestinal epithelium during CS.

Successful use of porcine small intestinal submucosa grafts for the treatment of a deep melting corneal ulcer in a foal

Successful use of porcine small intestinal submucosa grafts for the treatment of a deep melting corneal ulcer in a foal

Kinetics of Torque Teno virus DNA in stools may predict occurrence of acute intestinal graft versus host disease early after allogeneic hematopoietic stem cell transplantation.

Torque Teno virus (TTV) DNA load in blood may act as a marker of immune competence after allogeneic hematopoietic stem cell transplant recipients (allo-HSCT). Conflicting data have been reported as to the value of this biomarker for anticipating acute Graft versus host disease (aGvHD) occurrence. Here, we hypothesized that quantitation of TTV DNA load in stool specimens early after allo-HSCT could be used to identify patients at high risk of acute intestinal graft versus host disease (aIGvHD). In this prospective two-center study, we recruited a total of 83 nonconsecutive adult patients undergoing allo-HSCT. The study period comprised the first 120days after allo-HSCT. TTV DNA was quantitated in paired stool samples collected at a median of 2days prior to cell infusion and at a median of 14days after allo-HSCT by real-time PCR. Thirty-seven patients developed aGVHD, of whom 25 had aIGVHD (diagnosed at a median of 42days after allo-HSCT). Median TTV DNA load values in posttransplant stools specimens were comparable (P=.34) in patients with or without subsequent aIGvHD; nevertheless, a falling trajectory (decrease in TTV DNA load >0.5 log10 copies/0.1g) in paired pretransplant and posttransplant specimens was independently associated with the occurrence of aIGvHD (OR, 5.2; 95% CI, 1.3-21.3; P=.02). Notably, displaying a rising trajectory had a negative predictive value of 87.5% for aIGvHD. In summary, in this hypothesis-generating study, we suggest that the decrease in TTV DNA load from baseline in stool specimens may identify patients at risk of aIGVHD.

Multiple rare‐earth magnet bead ingestion in a pediatric liver‐small bowel‐pancreas transplant recipient: A case report and lessons learned

Ingestion of rare-earth magnet beads in children has been a public health concern. The potential risk of swallowing multiple magnets is related to magnet attraction to each other, resulting in serious gastrointestinal complications, such as entero-enteric fistula formation, peritonitis, bowel ischemia or necrosis, bowel perforation, and potentially death. We describe the clinical outcome of a 10-year-old child with a liver-small bowel-pancreas transplant who swallowed 26 rare-earth magnetic beads. The patient presented with fever and abdominal pain. Due to difficulty locating the magnets and post-surgical anatomy changes, only 25 magnets were removed endoscopically. After the procedure, she continued to have abdominal distention and fever, leading to further investigation and subsequently an exploratory laparotomy, which confirmed a walled-off perforation. She was treated conservatively with bowel rest and antibiotics, without the need for small bowel graft resection. She recovered well and was eventually discharged on her home enteral feeding regimen. This case emphasizes the importance of taking a good history and having a high index of suspicion to diagnose this dangerous clinical condition, especially in children with an associated predisposing condition for foreign body ingestion, such as developmental delay. Early diagnosis of multiple magnet bead ingestion and prompt detection of its complications in pediatric intestinal transplant recipients could help initiate appropriate intervention and prevent intestinal graft loss.

Immunosuppression in Visceral Transplantation: Current Trends and Future Perspectives.

Visceral transplant represents an immunologic challenge due to high intestinal graft immunogenicity. Over the last 20 years, significant advances in immunosuppression regimens have resulted in excellent short-term outcomes. Currently, visceral transplant is the standard of care for patients with gut failure having life-threatening complications and complex abdominal pathology. In this review, we describe immunosuppressive strategies in the visceral transplant field.

GRAFTED COLON IN INTESTINAL TRANSPLANTATION: DOES IT MAKE A DIFFERENCE IN PATIENTS OUTCOME?

Introduction: To include the colon as part of an intestinal or multivisceral graft is still a matter of debate. While some groups consider that it might be important for water absorption and residue breakdown without posing risks to patients, others state that its inclusion could result in an increase in infectious complications. Our aim was to analyze if the presence of the grafted colon in our patients has meant differences in their outcome. Methods: Retrospective review of our historical series of intestinal and multivisceral transplants comparing patients that received a colon as part of the graft to those that didn’t. A total of 107 patients received an intestinal or multivisceral graft between 1999-2018. Main indications were short gut syndromes (60 patients, 56.1%), motility disorders (16 patients, 15%) and untreatable diarrheas (14 patients, 13.1%). It was used a graft without colon in 61[group no colon(33 M, 28 F)] and with colon in 46 [group colon (27 M, 19 F)].We compared the appearance of complications (such as rejection or infections) and survival curves adjusted by treatment protocol. A p-value below 0.05 was considered statistically significant. Results: Average ages and weights at transplant were similar in both groups, with 67.5 months (6-361) and 17.2 Kg (4-52.7) in patients without a grafted colon and 64 months (6-216) and 16 Kg (3-59.2) in patients with colon. One hundred and two patients had a small bowel stoma. Timing of stoma take-down was similar in no colon group compared to colon group, with a median of 9.5 (1-125) months and 8 (1-50) months respectively. Rates of acute and chronic rejection were similar in both groups (39%/10% no colon vs35%/4%colon).Rates of GVHD (15% no colon vs15% colon) and PTLD (20% no colon vs13% colon)were also similar. Median of septic episodes was 2 in both [no colon (0-8),colon (0-6)].Among the multiple infectious agents analyzed, only clostridium showed a statistically significant higher rate of infection in colon group (2% no colon vs15% colon). Patient and graft survival, adjusted by immunosuppression protocols, did not show differences. Conclusion: Colon inclusion as part of the intestinal graft does not produce a higher rejection, GVHD or PTLD rates, nor a survival decrease. Even though the infection rate is also similar, there are differences in the infectious agents between the groups.

THE HISTOLOGIC AND MOLECULAR ALTERATIONS DURING THE COLD STORAGE OF HUMAN RIGHT COLON

Introduction: Colon transplantation is being increasingly performed together with the small intestine and other viscera due to increased water absorption and improved renal function. The small intestine is particularly sensitive to ischemia/preservation-reperfusion injury to ischemia yet the colon alterations incurred by cold storage (CS) are basically unknown. We set out to study the histological and molecular changes developing during the preservation of the human colon. Materials and methods: Following aortic perfusion with IGL-1 solution, the right colon was obtained from nine multiorgan deceased brain-dead donors. No evacuation of the luminal content was performed. Samples were taken after 8h, 14h and 24 hours of cold preservation and histology (Hematoxillin-eosin), goblet cells (Alcian blue staining) and apoptosis (active caspase-3 staining) were evaluated. Tight junction protein zonula-occludens (ZO)-1 and claudin-1 (cldn-1) were also studied using immunofluorescence and Western blot. Results and Discussion: During the first 8h of CS the colonic mucosa revealed minimal alterations, with the epithelium tightly adherent to the underlying lamina propria. The Goblet cells were abundant and fully repleted with mucins. After 14h the overall mucosal architecture was well maintained but a discrete detachment (edema) was noted extending under the epithelium in the luminal half of the crypts. Both the epithelial continuity and Goblet cells were well maintained. After 24h the epithelial layer detached further from the lamina propria. Enterocyte apoptosis (active caspase-3) was not observed. Immediately after retrieval the colon revealed strong, reticular staining around the apical pole (ZO-1) and basolateral membrane (cldn-1) from the lumen down to the crypt bottom. Eight hours of CS induced minimal molecular changes but after 14h we found maintained but weaker ZO-1 staining at the mucosal surface and broader cldn-1 staining pattern along the crypts. After 24h, ZO-1 was maintained as a continuous, although weaker line along the apex of the colonic cells (possibly degradation) whereas cldn-1 sizeable cytoplasmic staining suggesting internalization. Taken together, these findings suggest a certain ischemic resilience of the human colon and should partly relieve the concerns over the mucosal barrier injury when this intestinal segment is transplanted as part of a composite intestinal graft. However, the molecular alterations may imply that fluid and electrolyte transport may be impaired. Conclusions: The human colon tolerates very well up to 14h of CS, with minimal cellular and molecular changes. The small intestine remains the most sensitive part of a visceral graft.

THE EFFECT OF A PAK-2 INHIBITOR ON MACROPHAGE DIFFERENTIATION/POLARIZATION IN A RAT SMALL INTESTINAL TRANSPLANTATION MODEL

Introduction: PQA-18 (prenylquinoline carboxy derivative 18) is a novel immunosuppressant that inhibits PAK-2 and suppresses cytokine production and macrophage (Mφ) differentiation/proliferation. The effect of PQA-18 was evaluated using a rat small intestine transplant model. Methods: Male Dark Agouti (DA) (RT-1a) and Lewis (RT-1l) rats, 7 to 9 weeks old, were used as donors and recipients, respectively. An approximately 15 cm ileal grafts from the donor was heterotopically transplanted to the recipient rats. Recipients were administered PQA-18 (4 mg/kg/day) intraperitoneal injection from post-operative day1 (POD1) for two weeks. (1) The survival time of the graft was compared between the non-administration group (ITx-g) and the PQA administered group (PQA-g). The rejection was manifested by progressive stoma ischemia, necrosis and the development of an abdominal mass, based on our previous studies. (2) At POD6, CD3 + T cells were separated from recipient mesenteric lymph nodes and mixed lymphocyte reaction (MLR) was performed. (3) Further, the % of Mφ in the graft mesenteric lymph node (gMLN) and graft Peyer’s patch (gPP) was measured by FACS. (4) Bone marrow stem cells of Lewis rat were cultured with G-CSF for 4 days, with or without PQA-18, and the differentiation/proliferation of Mφ was also measured by FACS. Results: (1) The graft survival time was prolonged from 7.0 ± 0.77 days in ITx-g (n = 9) to 10.7 ± 1.26 days in PQA-g (n = 10) (p <0.001). However, there was no difference between the two groups in serum creatinine and BUN on POD10 and POD14, measured for the evaluation of renal function. (2) MLR showed a suppression of T cell proliferation in PQA-g compared with ITx-g: 9.44 ± 1.21 vs 4.71 ± 0.55 (n = 4) (p <0.05), respectively. (3) The % of Mφ in the graft was 60.55 ± 2.18% (ITx-g) vs 45.20 ± 3.20% (PQA-g)(n = 6) (p <0.01) for gMLN and 42.42 ± 3.61% (ITx-g) vs 29.8% ± 3.21% (PQA-g) (n = 6) for gPP (p <0.05). In addition, the decreation of Mφ was observed in all cases of PQA-g. (4) The % of Mφ differentiation was reduced in the dose dependent manner. The group with 20μM of PQA-18 showed 5.01 ± 2.09% (n = 6), vs 14.45 ± 2.40% (control) (p <0.05). Conclusion: PQA-18 significantly prolonged the survival of rat small intestinal grafts by suppressing the Mφ infiltration in the grafts and lymph nodes. JSPS KAKENHI Grant Number JP17K17001.

Oral nutritional support to adult patients with acute intestinal Graft Versus Host Disease (GVHD): A proposal for dietary intervention as a model to clinical trials

Acute Graft Versus Host Disease (GVHD) affects about 20%-80% of the patients after the hematopoietic stem cell transplant (HSCT) and it is amongst the main causes of morbidity and mortality both in children and adults. The intestine is one of the most affected organs by GVHD causing important alterations in the nutritional status and quality of life, considering that the dysfunctional intestine could decrease food intake as well as an inappropriate dietary plan could worsen the clinical condition. In addition to GVHD, chemotherapy conditioning regimen suppresses the immune system, promotes mucositis and increases the risk of infectious complications. Taking the above into consideration, when per oral diet is possible; the food choices should be carefully planned and monitored to promote nutritional support and avoid worsening the intestinal function and clinical condition. This work was aimed to present a practice guideline proposal, to be validated, based on literature review, regarding to oral dietary recommendations for acute intestinal GVHD after HTSC. Two research phases were defined: Phase one: evidence-based literature review; Phase 2: Practice Guideline Proposal. 1: Evidence based literature review SEARCH METHODS: A literature review (1997-2019) was performed including PubMed, in English, and Lilacs, in Portuguese electronic database to address the subject of dietary intervention for intestinal GVHD related to the HSCT, with children and adults, whose receiving oral or tube feeding nutrition therapy. The study selection was based on the PRISMA method. Controlled clinical trials were searched. Randomization was not possible considering the rare condition. Two independent authors assessed the abstracts of the selected studies to determine the articles feasible to compose the review as the base to elaborate the practice guideline proposal protocol, object of the present study. To determine the level of evidence of the selected article, GRADE criteria were used. One controlled clinical trial study was included. The study was developed in Japan with a total of 35 patients. The dietary plan was characterized by gradual increasing food consistency/density. They found better nutritional parameters in the treated group, however, following GRADE criteria, we rated the quality of evidence as very low. We could not demonstrate confidence in the effect estimate based on the selected study. However, considering the lack of literature information and the relevance of the topic, we decided to proceed and propose a practice guideline for an oral diet protocol for acute intestinal GVHD as a reference to be a starting point to validate protocols in future clinical trials. 2: Practice Guideline Proposal The criteria to elaborate the protocol were based on the RIGHT Statement. In addition to the literate information about diet and intestinal health, recommendations already adopted in the Service of Bone Marrow Transplant in the Complex Hospital of Clinics of Curitiba, in the state of Paraná, Brazil, were also considered.

Human Small Intestine Transplantation: Segmental Susceptibility to Ischemia Using Different Preservation Solutions and Conditions

Background and AimsAmong all transplanted abdominal organs, the small intestine is one of the most ischemia sensitive. Appropriate graft selection, procurement, and preservation are crucial for optimum graft and patient survival. We evaluated ischemic damage in human small intestine grafts under different hypothermic preservation conditions (cold static and continuous perfusion) and solutions: histidine-tryptophan-ketoglutarate (HTK) and University of Wisconsin (UW). MethodsFourteen small intestinal grafts were procured from deceased donors. HTK and UW were used for the vascular perfusion at the cross clamp, and UW, HTK, or Ringer Lactate were used for the luminal flush at the back table. Therefore, part of the same harvested intestine was stored in cold static storage and in continuous perfusion preservation (with intestinal perfusion unit) simultaneously. Histological samples were collected from the jejunum and ileum at different time points and different preservation conditions. The samples were collected before the initiation of cold storage (T0), after 8 hours of cold static (ST8), or after 8 hours of continuous perfusion preservation (PT8) (n = 161 samples). Blinded histological evaluation was conducted and ischemic damage was determined using the Park/Chiu scale. ResultsThe ileum had less ischemic damage than the jejunum, regardless of using static or continuous perfusion preservation. There was no significantly ischemic damage difference between intestinal grafts flushed and perfused with UW or HTK. ConclusionThe jejunum is more susceptible to ischemic injury than the ileum. UW and HTK are equivalent to preserve intestinal graft. This suggests that selective transplantation of ileum could reduce ischemia-related postoperative complications.

Onlay Repair Technique for the Management of Ureteral Strictures: A Comprehensive Review

Ureteroplasty using onlay grafts or flaps emerged as an innovative procedure for the management of proximal and midureteral strictures. Autologous grafts or flaps used commonly in ureteroplasty include the oral mucosae, bladder mucosae, ileal mucosae, and appendiceal mucosae. Oral mucosa grafts, especially buccal mucosa grafts (BMGs), have gained wide acceptance as a graft choice for ureteroplasty. The reported length of BMG ureteroplasty ranged from 1.5 to 11 cm with success rates of 71.4%-100%. However, several studies have demonstrated that ureteroplasty using lingual mucosa grafts yields better recipient site outcomes and fewer donor site complications than that using BMGs. In addition, there is no essential difference in the efficacy and complication rates of BMG ureteroplasty using an anterior approach or a posterior approach. Intestinal graft or flap ureteroplasty was also reported. And the reported length of ileal or appendiceal flap ureteroplasty ranged from 1 to 8 cm with success rates of 75%-100%. Moreover, the bladder mucosa, renal pelvis wall, and penile/preputial skin have also been reported to be used for ureteroplasty and have achieved satisfactory outcomes, but each graft or flap has unique advantages and potential problems. Tissue engineering-based ureteroplasty through the implantation of patched scaffolds, such as the small intestine submucosa, with or without cell seeding, has induced successful ureteral regeneration structurally close to that of the native ureter and has resulted in good functional outcomes in animal models.

Factors Associated With 5- and 10-Year Survival After Intestinal Transplantation in Infants and Children.

Intestinal transplantation is an option for permanent intestinal failure with parenteral nutrition intolerance. We sought to determine long-term intestinal graft survival in pediatric patients at our center and to identify factors influencing survival. Retrospective chart review of 86 patients transplanted between 2003 and 2013, targeting potential explanatory variables related to demographics, perioperative factors, and postoperative complications. Intestinal graft survival was 71% and 65% after 5 and 10 years, respectively. Five-year graft survival was attained in 79% of patients with a history of anatomic intestinal failure compared with 45% with functional intestinal failure (P = 0.0055). Compared with nonsurvival, 5-year graft survival was also associated with reduced incidences of graft-versus-host disease (2% vs 16%, P = 0.0237), post-transplant lymphoproliferative disorder (3% vs 24%, P = 0.0067), and de novo donor-specific antibodies (19% vs 57%, P = 0.0451) plus a lower donor-recipient weight ratio (median 0.727 vs 0.923, P = 0.0316). Factors not associated with 5-year intestinal graft survival included graft rejection of any severity and inclusion of a liver graft. Factors associated with graft survival at 10 years were similar to those at 5 years. In our experience, outcomes in pediatric intestinal transplantation have improved substantially for anatomic but not functional intestinal failure. Graft survival depends on avoidance of severe infectious and immunological complications including GVHD, whereas inclusion of a liver graft provides no obvious survival benefit. Reduced success with functional intestinal failure may reflect inherently increased susceptibility to complications in this group.

Type 3 innate lymphoid cells are associated with a successful intestinal transplant.

Although innate lymphoid cells (ILCs) play fundamental roles in mucosal barrier functionality and tissue homeostasis, ILC-related mechanisms underlying intestinal barrier function, homeostatic regulation, and graft rejection in intestinal transplantation (ITx) patients have yet to be thoroughly defined. We found protective type 3 NKp44+ ILCs (ILC3s) to be significantly diminished in newly transplanted allografts, compared to allografts at 6months, whereas proinflammatory type 1 NKp44- ILCs (ILC1s) were higher. Moreover, serial immunomonitoring revealed that in healthy allografts, protective ILC3s repopulate by 2-4weeks postoperatively, but in rejecting allografts they remain diminished. Intracellular cytokine staining confirmed that NKp44+ ILC3 produced protective interleukin-22 (IL-22), whereas ILC1s produced proinflammatory interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α). Our findings about the paucity of protective ILC3s immediately following transplant and their repopulation in healthy allografts during the first month following transplant were confirmed by RNA-sequencing analyses of serial ITx biopsies. Overall, our findings show that ILCs may play a key role in regulating ITx graft homeostasis and could serve as sentinels for early recognition of allograft rejection and be targets for future therapies.

Challenges and Pitfalls in the Engineering of Human Interleukin 22 (hIL-22) Secreting Lactobacillus reuteri.

Engineered microbes for the delivery of intestinally directed therapeutics is a promising avenue for the treatment of various intestinal diseases including inflammatory bowel disease (IBD) and intestinal graft vs. host disease (GVHD). This modality of treatment would allow for the targeted delivery of therapeutics to the site of inflammation or disease while minimizing the systemic side effects that often accompany treatment of these pathologies. Here, we show the challenges encountered and overcome in successfully engineering Lactobacillus reuteri to secrete high levels of biologically active human interleukin 22 (hIL-22). Initial hIL-22 constructs secreted high levels of hIL-22, however we found the majority of hIL-22 was cleaved and not biologically active. Several strategies were explored to improve the production of intact hIL-22, with the optimization of the signal sequence for peptide secretion having the most impact of production of intact hIL-22. This resulted in L. reuteri secreting high concentrations (up to 700 ng/mL) of hIL-22. Bioactivity of hIL-22 was confirmed by the secretion of interleukin 10 (IL-10) from the colon cancer derived epithelial cell line Colo205 and the secretion of Regenerating islet-derived protein 3 alpha (Reg3α) from human jejunal enteroids. The secretion of bioactive hIL-22 imposed a significant cost for L. reuteri as bacterial growth was significantly impaired upon induction. Future challenges and optimization strategies for the delivery of hIL-22 to the human intestinal tract are discussed.

P1704POST-TRANSPLANTATION LYPMHOPROLIFERATIVE DISORDER (PTLD) RISK AND PROGNOSTIC FACTORS IN KIDNEY AND LIVER TRANSPLANT RECIPIENTS

Abstract Background and Aims Post-transplantation lymphoprolipherative disorder [PTLD] is a serious, potentially fatal complication of transplantation [Tx], pathogenesis of which remains to be fully understood. Due to the intrinsic difficulty of assembling a large cohort of rare disease patients, most research papers have investigated PTLD in the general graft recipient population. They report however, that the relative risk of disease development significantly varies in relation to the type of transplanted organ, with multiorgan and intestinal graft recipients possessing the highest risk (RR=239.5), liver (RR=29.9) and the lowest for kidney transplant recipients (RR=12.6). The aim of this study was to investigate the factors contributing to the development, course, treatment and outcomes of PTLD and compare their impact on the populations of liver [LTR] and kidney [KTR] transplant recipients. Method In this retrospective cohort study we have included all KTRs and LTRs diagnosed with PTLD at our centres between 2002 and 2017. The following data were collected from the patients’ medical records: immunosuppression (IS), viral infections, PTLD type, treatment and outcomes. Mann-Whitney U-test was used to assess the differences in group composition, and the Log-rank test was used to compare Kaplan-Meier curves. Statistical analysis was performed in R version 3.2.3., p-values below .05 were considered statistically significant. Results We have identified 23 LTR and 16 KTR who matched our inclusion criteria. The mean age was 40.69 years. 61.5% of the patients were male, 38.5% female. Analysis of Kaplan-Meier curves revealed that PTLD occurred earlier in: LTRs (p&amp;lt;.001); patients above the median age of 45 years at Tx (p=.002); patients whose IS regimens at the time of PTLD diagnosis contained tacrolimus [TAC] (p&amp;lt;.001) or did not contain cyclosporin [CsA]. Among KTRs PTLD was diagnosed earlier in males (p&amp;lt;0.05), patients over 45 years at Tx (p&amp;lt;0.05), and those receiving TAC-containing IS regimens at PTLD diagnosis (p&amp;lt;0.05). These factors were not statistically significant for LTRs, among whom PTLD development was affected by the presence of MMF in IS regimens at diagnosis (p&amp;lt;0.05). Survival time was longer for patients receiving MMF-containing IS regimens (p&amp;lt;0.05). LTRs were more likely than KTRs to achieve complete remission in response to treatment (p&amp;lt;0.05). Conclusion Our results indicate, that in comparable KTR and LTR populations, the course of PLTD and response to treatment vary significantly. Factors such as patients’ age at transplantation, sex, type of maintenance IS have a different impact depending on graft type. In our opinion these findings, when applied to further research, could enhance our ability to identify patients at risk and potentially lead to the formation of more personalised guidelines to the diagnosis and treatment of PTLD.

Normothermic extracorporeal membrane oxygenation support: Improving the function of intestinal grafts obtained from cardiac death donors.

Extracorporeal membrane oxygenation (ECMO) could ameliorate the energy status and viability of bowel grafts from cardiac death donors. However, the function of these grafts after transplantation is not clear. The purpose of the study was to evaluate the early function of intestinal grafts after transplantation from expected cardiac death donors supported with normothermic extracorporeal support using a porcine allogeneic orthotopic segmental small bowel transplantation model. Eighteen domestic crossbred donor pigs were assigned to living donation (LD), donation after cardiac death (DCD), and ECMO groups. In the LD group, small bowels were harvested and preserved immediately in cold storage. In the other two groups, the donor pigs received conventional rapid recovery treatment or 1-hour normothermic extracorporeal support after 10-minutes expected cardiac arrest. Subsequently, the small bowels were removed and preserved in cold storage. After 5-6hours of preservation, small bowel grafts were transplanted into the recipient pigs that underwent enterectomy. The pathology and electron microscopy results, cell apoptosis rate, tight junction protein expression level in the intestinal mucosa, and plasma endotoxin level were evaluated after transplantation. All grafts functioned on the basis of the maltose absorption test results at day 7 after transplantation. There were no significant differences in the morphological changes in the intestinal mucosa among the three groups at day 7 after transplantation. The cell apoptosis rate and plasma endotoxin level in the ECMO group did not differ significantly than those in the LD group, but were evidently lower than those in the DCD group (P<.001). The intestinal absorptive function improved significantly in the ECMO group in contrast with that in the DCD group (P<.001). Short-term ECMO intervention can alleviate ischemia-reperfusion injuries in intestinal grafts and improve intestinal absorptive function in the early stage after transplantation. Reducing caspase-3 protein expression and cell apoptosis in the intestinal mucosa may be one of the protective mechanisms of ECMO intervention.

A novel histidine-tryptophan-ketoglutarate formulation ameliorates intestinal injury in a cold storage and ex vivo warm oxygenated reperfusion model in rats.

The present study aims to evaluate protective effects of a novel histidine-tryptophan-ketoglutarate solution (HTK-N) and to investigate positive impacts of an additional luminal preservation route in cold storage-induced injury on rat small bowels. Male Lewis rats were utilized as donors of small bowel grafts. Vascular or vascular plus luminal preservation were conducted with HTK or HTK-N and grafts were stored at 4°C for 8 h followed by ex vivo warm oxygenated reperfusion with Krebs-Henseleit buffer for 30 min. Afterwards, intestinal tissue and portal vein effluent samples were collected for evaluation of morphological alterations, mucosal permeability and graft vitality. The novel HTK-N decreased ultrastructural alterations but otherwise presented limited effect on protecting small bowel from ischemia-reperfusion injury in vascular route. However, the additional luminal preservation led to positive impacts on the integrity of intestinal mucosa and vitality of goblet cells. In addition, vascular plus luminal preservation route with HTK significantly protected the intestinal tissue from edema. HTK-N protected the intestinal mucosal structure and graft vitality as a luminal preservation solution. Additional luminal preservation route in cold storage was shown to be promising.

Beyond 10years, with or without an intestinal graft: Present and future?

Long-term outcomes in children undergoing intestinal transplantation remain unclear. Seventy-one children underwent intestinal transplantation in our center from 1989 to 2007. We report on 10-year posttransplant outcomes with (group 1, n=26) and without (group 2, n=9) a functional graft. Ten-year patient and graft survival rates were 53% and 36%, respectively. Most patients were studying or working, one third having psychiatric disorders. All patients in group 1 were weaned off parenteral nutrition with mostly normal physical growth and subnormal energy absorption. Graft histology from 15 late biopsies showed minimal abnormality. However, micronutrient deficiencies and fat malabsorption were frequent; biliary complications occurred in 4 patients among the 17 who underwent liver transplantation; median renal clearance was 87mL/min/1.73m2 . Four patients in group 1 experienced late acute rejection. Among the 9 patients in group 2, 4 died after 10years and 2 developed significant liver fibrosis. Liver transplantation and the use of a 3-drug regimen including sirolimus or mycophenolate mofetil were associated with improved graft survival. Therefore, intestinal transplantation may enable a satisfactory digestive function in the long term. The prognosis of graft removal without retransplantation is better than expected. Regular monitoring of micronutrients, early psychological assessment, and use of sirolimus are recommended.