Neuropsychological and biopsychosocial evolution, therapeutic adherence and unmet care needs during paediatric transplantation: study protocol of a mixed-methods design (observational cohort study and focus groups) - the TransplantKIDS mental health project.

The present article describes the protocol of a mixed-methods study (an observational cohort design and focus groups), aimed to examine neuropsychological functioning and other biopsychosocial outcomes, therapeutic adherence and unmet care needs in paediatric population undergoing solid organ or allogeneic hematopoietic transplant during the pre- and post-transplant phases. Following a multi-method/multi-source approach, neuropsychological domains will be comprehensively measured with objective tests (SDMT, K-CPT 2/CPT 3, TAVECI/TAVEC, WISC-V/WAIS-IV Vocabulary and Digit Span subtests, Verbal Fluency tests, Stroop, ROCF, and TONI-4); ecological executive functioning, affective and behavioral domains, pain intensity/interference, sleep quality and therapeutic adherence will be assessed through questionnaires (parent/legal guardians-reported: BRIEF-2 and BASC-3; and self-reported: BASC-3, BPI, PROMIS, AIQ and SMAQ); and blood levels of prescribed drugs will be taken from each patient's medical history. These outcomes will be measured at pre-transplant and at 4-weeks and 6-months post-transplant phases. The estimated sample size was 60 patients (any type of transplant, solid organ, or hematopoietic) from La Paz University Hospital (Madrid, Spain). Finally, three focus group sessions will be organized with patients, parents/guardians, and transplant clinicians (n = 15, with 5 participants per group), in order to qualitatively identify unmet care needs during the pre-, and post-transplant stages of the process. The study protocol was registered at ClinicalTrials.gov (NCT05441436).

The Role of Indocyanine Green in Pediatric Gastrointestinal Surgery: Systematic Review.

The use of near-infrared fluorescence imaging with indocyanine green (ICG) is actually considered as a very useful tool in decision-making strategy during challenging surgical procedures with a growing evidence in the literature. Our aim is to perform a systematic review focusing on ICG applications in gastrointestinal surgery. We conducted a systematic review with narrative synthesis in conformity with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines using PubMed, Medline, and EMBASE databases to identify articles describing the gastrointestinal perioperative use of ICG in children. We extracted data on study design, demographics, surgical indications, ICG dose, and perioperative outcomes. Eleven articles, including 94 pediatric patients, from 2013 to 2022 met the inclusion criteria for narrative synthesis in our systematic review, of which 6/11 (54.5%) were case reports, 4/11 (36.4%) were retrospective studies, and 1/11 (0.1%) were case series. Current clinical applications of ICG in gastrointestinal pediatric surgery included: esophagogastric surgery in 4/11 articles (36.4%), intestinal and pancreatic surgery in 3/11 articles (27.2%), and colorectal surgery in 4/11 articles (36.4%). ICG fluorescence in gastrointestinal pediatric surgery is a promising and safe technology that facilitates intraoperative localization of anatomical structures to achieve a more precise dissection and avoid injury to other adjacent tissues. It can be considered as a meaningful tool for assessing intestinal viability, as it provides objective data on tissue perfusion, and can impact the intraoperative decision in reconstructive surgeries requiring anastomosis. Future studies are needed to confirm these initial promising results. The lack of comparative and prospective studies is still the main limitation.

Neutrophil-to-lymphocyte ratio as a predictor of primary vesicoureteral reflux evolution in children with associated acute pyelonephritis.

Background: Neutrophil-to-lymphocyte ratio (NLR) has been recently postulated as an inflammatory biomarker for the diagnosis of vesicoureteral reflux (VUR). The aim of this study is to determine the role of NLR as a predictor of evolution of primary VUR in patients with associated acute pyelonephritis (APN). Methods: A retrospective observational cohort study was performed in patients with APN episodes with associated primary VUR diagnosed between 2013-2020. Patients were divided into two groups according to VUR evolution after APN: group A [spontaneous resolution (SR)] and group B [VUR complications development (CD) during follow-up: new APN or renal function worsening]. Demographic, prenatal, laboratory, microbiological and radiological data were analysed. Sensitivity and specificity for CD of VUR was determined by receiver operating characteristic (ROC) curves. Results: A total of 1,146 episodes of APN were analysed of which 273 patients with APN and associated primary VUR were finally included (median age of 11 months at APN diagnosis). SR of VUR occurred in 169 patients (SR group), while CD were observed in the remaining 104 patients (CD group). No differences in demographic, prenatal, microbiological and radiological features were observed. CD patients had significantly higher levels of leukocytes, neutrophils, NLR, C-reactive protein and creatinine. NLR was the parameter with the highest area under the curve (AUC =0.966) for predicting the development of VUR complications (cut-off point =3.41) with a maximum sensitivity of 92.7% and specificity of 91.1% (P<0.001). Conclusions: NLR may be considered as a simple and cost-effective predictor of clinical outcome of VUR, which may correlate with the increased risk of developing complications of primary VUR after an episode of APN. Therefore, it should be included in the management algorithm for these patients, although future prospective studies are still required to confirm these results.

Parental Presence during Induction of Anesthesia and Emergence Delirium Influence the Incidence of Postoperative Maladaptive Behavioral Changes.

OBJECTIVE: Surgical intervention in pediatric patients can cause variable degrees of psychological stress with potential consequences in the perioperative period and even in the long term, after hospital discharge in the form of behavioral changes days and months later. The aim of our study was to determine which preoperative preparation strategy reduces postoperative maladaptive behavioral changes in children undergoing ambulatory pediatric surgery. MATERIALS AND METHODS: This prospective observational study included 638 pediatric American Society of Anesthesiologists physical status I or II patients who underwent ambulatory pediatric surgery. They were grouped into four preoperative preparation groups: not premedicated (NADA), premedicated with midazolam (MDZ), parental presence during induction of anesthesia (PPIA), and parental presence during induction of anesthesia and premedicated with midazolam (PPIA + MDZ). All patients included in the study were contacted by telephone during 1 year posthospital discharge to assess the postoperative maladaptive behavioral changes using the Posthospitalization Behavior Questionnaire (PHBQ). We performed a multivariate analysis to evaluate the influence of type of preparation and behavioral changes. RESULTS: Patients in the PPIA and PPIA + MDZ preparation groups presented less postoperative maladaptive behavioral changes compared to patients in the NADA and MDZ groups (odds ratio [OR]: 1.8 [1.1-2.8] and OR 2.2 [1.03-4.49]) during the first week and first month. The intensity of emergence delirium measured by the Pediatric Anesthesia Emergence Delirium (PAED) scale increases the probability of postoperative maladaptive behavioral changes (OR: 1.05 [1.006-1.103]). CONCLUSION: The presence of parents during induction of anesthesia (PPIA and PPIA + MDZ) is a very effective strategy in reducing postoperative behavioral changes. These benefits are more significant in children under 5 years of age.

Mucosal appendicitis: How can it be differentiated from nonappendicitis?

OBJECTIVES: Mucosal appendicitis is defined by neutrophilic infiltration limited to the mucosa, with no transmural invasion; it is currently a controversial entity. The aim of our study was to determine whether mucosal appendicitis represents an early stage of acute appendicitis (AA) or should be considered a negative appendectomy. METHODS: A retrospective study was performed of children with suspected AA who underwent surgical treatment between 2017 and 2020. The participants were divided into 2 groups according to histologic appendiceal findings: mucosal appendicitis (MA) and negative appendicitis (NA). Demographic, clinical, ultrasound, and laboratory features were compared between the groups. RESULTS: A total of 1269 patients with suspected appendicitis in whom appendectomy was performed were included, with a median age of 10.5 years. Mucosal appendiceal inflammation was histologically confirmed in 30 cases (MA group), while no inflammation or other pathologic findings were observed in 25 cases (NA group), with no differences in demographic, clinical, or ultrasound features between the groups. Those in the MA group presented with significantly higher leukocyte and neutrophil counts and higher neutrophil to lymphocyte ratios (NLRs) than those in the NA group (P < .001). The NLR was the parameter with the highest area under the curve (0.736) for the diagnosis of MA. A cutoff of 3.20 was established, with a maximum sensitivity and specificity of 62.5% and 78.9%, respectively. CONCLUSIONS: Mucosal appendicitis presents with laboratory and histologic inflammatory features that can be distinguished from nonappendicitis and should therefore be considered a pathologic entity within the spectrum of AA. Preoperative leukocyte and neutrophil counts and NLRs may help reduce the number of negative appendectomies.

How does the number of training years in pediatric surgery affect appendectomy outcomes?

INTRODUCTION: Appendectomy has traditionally been considered as a training operation for junior pediatric surgeons during their training period. However, with the increase of laparoscopic appendectomy, there has been a growing concern about the performance of this procedure by junior trainees. Our aim is to analyze intra-/postoperative appendectomy outcomes according to the number of training years during Pediatric Surgical residency training program. METHODS: A retrospective study was performed in patients who underwent appendectomy between 2018 and 2021 in our institution, who were divided into 5 groups according to the number of training years of the junior surgeon who performed the intervention (Y1-Y5). Demographics, complicated appendicitis rate, operation time, and postoperative complications were compared. A stratified analysis according to the technique performed (open/laparoscopic) was performed. RESULTS: A total of 1274 appendectomized patients were analyzed, of which 1257 (98.7%) were operated on by junior trainees (81 in Y1; 407 in Y2; 337 in Y3; 261 in Y4; and 171 in Y5) without demographic differences between groups. As the year of training increased, an elevation in complicated appendicitis rate was observed, although without statistically significant differences. However, laparoscopic/open appendectomies ratio increased with increasing year of training (p < 0.001). Operative time decreased significantly with increasing year of training (p < 0.001), both in open and laparoscopic appendectomies. There were no significant differences in postoperative complications, nor in the stratified analysis according to surgical technique. CONCLUSION: Appendectomy performed by junior pediatric surgery trainees can be considered a safe procedure from the first year of training, regardless of the technique used.

Mortality predictive factors in congenital hepatic hemangioma: a case-control study.

Congenital hepatic hemangiomas (CHHs) are benign vascular tumors whose clinical, histological, and genetic correlation has recently been described in patients with long-term survival, although no mortality risk factors have been identified to date. The aim of this study is to analyze predictors of mortality in patients with CHH. A retrospective single-center case-control study of consecutive CHH patients diagnosed in our institution between 1991 and 2021 was performed, who were classified into two groups according to their survival. Demographic, gestational, imaging, and laboratory data at diagnosis were collected and compared between both groups. A total of 29 patients were included (12 males; 17 females) of whom 5 died as a result of CHH evolution due to cardiac failure and coagulopathy, with a median age of 11 days until death. No differences in demographic or gestational data were reported. There were neither differences when comparing imaging tests, nor in location, number of affected liver segments, or CHH estimated volume. Upon laboratory data at diagnosis, deceased patients had a significant elevation of median liver enzymes [glutamic-oxaloacetic transaminase (359 u/L vs. 45 u/L; p < 0.01) and glutamic-pyruvic transaminase (313 u/L vs. 20 u/L; p < 0. 01)], as well as a decreased median platelet count (85,250/µL vs. 337,000/µL; p < 0.01), prothrombin activity (54% vs. 93%; p < 0.01), and fibrinogen (131 mg/dL vs. 284 mg/dL; p < 0.01), with no differences in blood count or biochemistry data. CONCLUSIONS: CHH clinical behavior can be innocuous or life-threatening. Thrombocytopenia, coagulation disorders, and increased liver enzymes at diagnosis seem to be the main predictors of mortality. WHAT IS KNOWN: • Congenital Hepatic Hemangiomas (CHHs) are benign vascular tumors whose clinical behavior can be innocuous or life-threatening. WHAT IS NEW: • Thrombocytopenia, coagulation disorders and increased liver enzymes at diagnosis seem to be the main predictors of mortality in these patients.

When less is more: Experimental Bishop-Koop technique for reduction in the use of laboratory animals for intestinal pathophysiological studies.

The use of animals to gain knowledge and understanding of diseases needs to be reduced and refined. In the field of intestinal research, because of the complexity of the gut immune system, living models testing is mandatory. Based on the 3Rs (replacement, reduction and refinement) principles, we aimed to developed and apply the derived-intestinal surgical procedure described by Bishop and Koop (BK) in rats to refine experimental gastrointestinal procedures and reduce the number of animals used for research employing two models of intestinal inflammation: intestinal ischemia-reperfusion injury and chemical-induced colitis. Our results show the feasibility of the application of the BK technique in rodents, with good success after surgical procedure in both small and large intestine (100% survival, clinical recovery and weight regain). A considerable reduction in the use of the number of rats in both intestinal inflammation models (80% in case of intestinal ischemia-reperfusion damage and 66.6% in chemical-induced colitis in our experimental design) was achieved. Compared with conventional experimental models described by various research groups, we report excellent reproducibility of intestinal damage and functionality, survival rate and clinical status of the animals when BK is applied.

Familial CD45RA- T cells to treat severe refractory infections in immunocompromised patients.

Background: Immunocompromised patients are susceptible to high-risk opportunistic infections and malignant diseases. Most antiviral and antifungal drugs are quite toxic, relatively ineffective, and induce resistance in the long term. The transfer of pathogen-specific Cytotoxic T-Lymphocytes has shown a minimal toxicity profile and effectiveness in treating Cytomegalovirus, Adenovirus, Epstein - Barr virus, BK Virus and Aspergillus infections, but this therapy have the main limitations of regulatory issues, high cost, and absence of public cell banks. However, CD45RA- cells containing pathogen-specific memory T-cells involve a less complex manufacturing and regulatory process and are cheaper, feasible, safe, and potentially effective. Methods: We present preliminary data from six immunocompromised patients: four who had severe infectious diseases and two who had EBV lymphoproliferative disease. All of them underwent multiple safe familial CD45RA- T-cell infusions as adoptive passive cell therapy, containing Cytomegalovirus, Epstein - Barr virus, BK virus, and Aspergillus-specific memory T-cells. We also present the method for selecting the best donors for CD45RA- cells in each case and the procedure to isolate and store these cells. Results: The infusions were safe, there was no case of graft-versus host disease, and they showed a clear clinical benefit. The patients treated for BK virus nephritis, Cytomegalovirus encephalitis, Cytomegalovirus reactivation, and disseminated invasive aspergillosis experienced pathogen clearance, complete resolution of symptoms in 4-6 weeks and a lymphocyte increase in 3 of 4 cases after 3-4 months. Donor T cell transient microchimerism was detected in one patient. The two patients treated for EBV lymphoproliferative disease underwent chemotherapy and several infusions of CD45RA- memory T-cells containing EBV cytotoxic lymphocytes. Donor T-cell microchimerism was observed in both patients. The viremia cleared in one of the patients, and in the other, despite the viremia not clearing, hepatic lymphoproliferative disease remained stable and was ultimately cured with EBV-specific Cytotoxic T-Lymphocytes. Conclusion: The use of familial CD45RA- T-cells containing specific Cytotoxic T-lymphocytes is a feasible, safe and potential effective approach for treating severe pathogen infections in immunocompromised patients through a third party donor. Furthermore, this approach might be of universal use with fewer institutional and regulatory barriers.

Indocyanine green navigation in minimally invasive resection of multiple metachronous pulmonary metastases of hepatoblastoma.

Pulmonary metastases from hepatoblastoma (HB) have traditionally been identified by preoperative computed tomography scan image evaluation, and intraoperative visual and palpatory examinations through thoracotomy have been generally recommended. However, the safety and accuracy of surgery can be problematic in patients with small multiple lung metastases due to postoperative respiratory dysfunction risk secondary to decreased residual lung capacity in wedge resections. We present an 8-month-old patient with metastatic HB with multiple metachronous pulmonary lesions in whom thoracoscopic lung resections were performed guided by indocyanine green (ICG) administered intravenously 24 h earlier (0.5 mg/kg). ICG fluorescence allowed identification and limited resection of lung parenchyma, avoiding postoperative respiratory dysfunction. A total of 16 lung lesions were resected during four operations (two bilateral and two right thoracoscopies), with no postoperative complications. ICG-guided thoracoscopic surgery allowed identification and resection of metastatic nodules in both lungs during the same procedure, achieving a hospital stay of less than 3 days for each intervention. The patient is currently 24 months old and remains asymptomatic, with no distant disease at the last imaging control. ICG-guided resection via a thoracoscopic approach is particularly useful in patients with multiple and/or metachronous metastases requiring multiple surgical interventions.

Experimental Assessment of Intestinal Damage in Controlled Donation After Circulatory Death for Visceral Transplantation.

There is an urgent need to address the shortage of potential multivisceral grafts in order to reduce the average time in waiting list. Since donation after circulatory death (DCD) has been successfully employed for other solid organs, a thorough evaluation of the use of intestinal grafts from DCD is warranted. Here, we have generated a model of Maastricht III DCD in rodents, focusing on the viability of intestinal and multivisceral grafts at five (DCD5) and twenty (DCD20) minutes of cardiac arrest compared to living and brain death donors. DCD groups exhibited time-dependent damage. DCD20 generated substantial intestinal mucosal injury and decreased number of Goblet cells whereas grafts from DCD5 closely resemble those of brain death and living donors groups in terms intestinal morphology, expression of tight junction proteins and number of Paneth and Globet cells. Upon transplantation, intestines from DCD5 showed increased ischemia/reperfusion damage compared to living donor grafts, however mucosal integrity was recovered 48 h after transplantation. No differences in terms of graft rejection, gene expression and absorptive function between DCD5 and living donor were observed at 7 post-transplant days. Collectively, our results highlight DCD as a possible strategy to increase multivisceral donation and transplantation procedures.

Impact of muscle mass on the prognosis of liver transplantation for infants with biliary atresia.

Background: Sarcopenia in adult cirrhotic patients is associated with increased morbidity and mortality whereas in children it is still being studied. Anthropometric variables in cirrhotic children are not reliable for assessing muscle mass as they may be altered by ascites, edema, and organomegaly. Measuring the area of the psoas showed good correlation with muscle mass in adults. We aimed to study in cirrhotic infants undergoing liver transplantation the association of the psoas area with liver transplant prognosis as well as with several analytical and anthropometric parameters used to evaluate nutritional status. Methods: Retrospective cohort of 29 infants with cirrhosis due to biliary atresia who underwent abdominal CT scan as a pre-transplant study. We measured the psoas muscle index (PMI) at L4-L5 since it best correlates with muscle mass in pediatric patients. As there are no validated cut-off points to define sarcopenia in children under one year of age, PMI was recorded as a continuous variable and correlated with different prognostic, clinical, and analytical variables. The SPSS 17.0 package was used for statistical analysis and a P < 0.05 was considered significant. Results: 29 infants (10 boys, 19 girls) were studied. 62% were Caucasian and the rest were South American. The mean age at CT scan was 8.5 months (range 3-15 months). There was a negative correlation between PMI and days of admission prior to liver transplant, previous infections, and bone fractures. Among the analytical parameters, cholinesterase, albumin, and prealbumin correlated positively with PMI (P < 0.05). No relationship was observed with anthropometric parameters: weight, height, BMI, brachial perimeter, or bioimpedance. During surgery, patients with lower PMI had a greater need for plasma transfusion, and in the immediate postoperative period, there was a longer stay in intensive care, more days of mechanical ventilation, and more days of hospital admission (P < 0.05). On the contrary, no relationship was found with other complications: bleeding, re-interventions, biliary leaks, rejection, thrombosis, re-transplantation, or infections. Conclusions: The decrease in muscle mass is associated with increased morbidity in infants with biliary atresia undergoing liver transplantation. Muscle mass in these patients cannot be adequately assessed with anthropometric measurements commonly used in the clinic.

Antibody-removal therapies for de novo DSA in pediatric intestinal recipients: Why, when, and how? A single-center experience.

Background: Donor-specific anti-HLA antibodies (DSA) impact negatively on the outcome of intestinal grafts. Although the use of antibody-removal therapies (ART) is becoming more frequent in the last few years, issues regarding their timing and effectiveness remain under discussion. Methods: In the present study, we report our experience with eight ART procedures (based on plasmapheresis, intravenous immunoglobulin, and rituximab) in eight pediatric intestinal and multivisceral transplants with de novo DSA (dnDSA). Results: ART were performed when dnDSA appeared in two contexts: (1) concomitant with rejection (acute or chronic) or (2) without rejection or any other clinical symptom. Complete DSA removal was observed in seven out of eight patients, showing an effectiveness of 88%. In the group treated for dnDSA without clinical symptoms, the success rate was 100%, with complete DSA removal and without rejection afterward. A shorter time between DSA detection and ART performance appeared as a significant factor for the success of the therapy (p = 0.0002). DSA against HLA-A and DQ alleles were the most resistant to ART, whereas anti-DR DSA were the most sensitive. In addition, the 8-year allograft survival rate in recipients undergoing ART was similar to that in those without DSA, being significantly lower in non-treated DSA-positive recipients (p = 0.013). Conclusion: The results confirm the effectiveness of ART in terms of DSA removal and allograft survival and encourage its early use even in the absence of clinical symptoms.

Nonhepatic Cancer in the Pediatric Liver Transplant Population: Guidelines From the ILTS-SETH Consensus Conference.

The incidence and geographical distribution of cancers in children are dramatically different from the adult population. Consequent to improvements in postcancer survival, there is a progressive increase in the number of patients requiring liver transplantation (LT) who are in remission from pretransplant malignancy (PTM). Conventionally, however, PTM has been considered a relative contraindication to LT. Furthermore, with improving post-LT survival now extending beyond decades, the cumulative effect of immunosuppression and the increasing risk of de novo cancers need to be acknowledged. A working group was formed to evaluate, discuss, and retrieve all the evidence and provide guidelines with regards to best practices surrounding nonhepatic cancer in the pediatric LT (PLT) population. Further subsections of research included (a) extrahepatic solid tumors, leukemia, lymphoma, and other hematological disturbances before PLT and (b) malignancies following PLT (including posttransplant lymphoproliferative disorders). This guidance provides a collection of evidence-based expert opinions, consensus, and best practices on nonhepatic cancers in PLT.

Parental Presence during Induction of Anesthesia Improves Compliance of the Child and Reduces Emergence Delirium.

INTRODUCTION: Preoperative stress and anxiety in pediatric patients are associated with poor compliance during induction of anesthesia and a higher incidence of postoperative maladaptive behaviors. The aim of our study was to determine which preoperative preparation strategy improves compliance of the child during induction and decreases the incidence and intensity of emergence delirium (ED) in children undergoing ambulatory pediatric surgery. MATERIALS AND METHODS: This prospective observational study included 638 pediatric American Society of Anesthesiologists I-II patients who underwent ambulatory pediatric surgery, grouped into four preoperative preparation groups: NADA (not premedicated), MDZ (premedicated with midazolam), PPIA (parental presence during induction of anesthesia), and PPIA + MDZ. The results were subsequently analyzed in four age subgroups: Group 1 (0-12 months), Group 2 (13-60 months), Group 3 (61-96 months), and Group 4 (> 96 months). Preoperative anxiety (modified Yale Preoperative Anxiety Scale [m-YPAS]), compliance of the child during induction (Induction Compliance Checklist [: ICC]), and ED (Pediatric Anesthesia Emergence Delirium scale) were analyzed in each group. RESULTS: Eighty-one percent of patients in the PPIA + MDZ preparation group presented a perfect compliance during the induction of anesthesia (ICC = 0), less preoperative anxiety (mean score m-YPAS = 26), less probability of ED (odds ratio: 10, 5 [3-37.5]; p < 0.05), and less ED intensity compared with the NADA group (1.2 vs. 5.8; p = 0.001). CONCLUSION: PPIA associated with midazolam premedication improves compliance during induction and decreases the incidence and intensity of ED.

Delayed introduction of sirolimus in paediatric intestinal transplant recipients: indications and long-term benefits.

To review our experience using sirolimus in a single centre paediatric intestinal transplantation cohort. Intestinal transplant patients with more than 3 months follow-up were divided into two groups according to their immunosuppression regimen: tacrolimus, (TAC group, n = 45 grafts) or sirolimus (SRL group, n = 38 grafts), which included those partially or completely converted from tacrolimus to sirolimus. The indications to switch were tacrolimus side effects and immunological complications. Survival and complications were retrospectively analysed comparing both groups. SRL was introduced 9 months (0 months-16.9 years) after transplant. The main cause for conversion was worsening renal function (45%), followed by haemolytic anaemia (21%) and graft-versus-host-disease (16%). Both groups showed a similar overall patient/graft survival (P = 0.76/0.08) and occurrence of rejection (24%/17%, P = 0.36). Immunological complications did not recur after conversion. Renal function significantly improved in most SRL patients. After a median follow-up of 65.17 months, 28/46 survivors were on SRL, 26 with monotherapy, with good graft function. Over one-third of our patients eventually required SRL conversion that allowed to improve their kidney function and immunological events, without entailing additional complications or survival impairment. Further trials are warranted to clarify the potential improvement of the standard tacrolimus maintenance by sirolimus conversion or addition.

Graft infusion of adipose-derived mesenchymal stromal cells to prevent rejection in experimental intestinal transplantation: A feasibility study.

BACKGROUND: Mesenchymal stromal cells (MSC) have been proposed as a promising complement to standard immunosuppression in solid organ transplantation because of their immunomodulatory properties. The present work addresses the role of adipose-derived MSC (Ad-MSC) in an experimental model of acute rejection in small bowel transplantation (SBT). MATERIAL/METHODS: Heterotopic allogeneic SBT was performed. A single dose of 1.5x106 Ad-MSC was intra-arterially delivered just before graft reperfusion. Animals were divided into CONTROL (CTRL), CONTROL+Ad-MSC (CTRL_MSC), tacrolimus (TAC), and TAC+Ad-MSC (TAC_MSC) groups. Each Ad-MSC groups was subdivided in autologous and allogeneic third-party groups. RESULTS: Rejection rate and severity were similar in MSC-treated and untreated animals. CTRL_MSC animals showed a decrease in macrophages, T-cell (CD4, CD8, and Foxp3 subsets) and B-cell counts in the graft compared with CTRL, this decrease was attenuated in TAC_MSC animals. Pro- and anti-inflammatory cytokines and some chemokines and growth factors increased in CTRL_MSC animals, especially in the allogeneic group, whereas milder changes were seen in the TAC groups. CONCLUSION: Ad-MSC did not prevent rejection when administered just before reperfusion. However, they showed immunomodulatory effects that could be relevant for a longer-term outcome. Interference between tacrolimus and the MSC effects should be addressed in further studies.