Inflammatory and hypoxic stress-induced islet exosomes released during isolation are associated with poor transplant outcomes in islet autotransplantation.

Islets experience enormous stress during the isolation process, leading to suboptimal endocrine function after total pancreatectomy with islet autotransplantation (TPIAT). Our investigation focused on inducing isolation stress in islets ex vivo, where proinflammatory cytokines and hypoxia prompted the release of stress exosomes (exoS) sized between 50 and 200 nm. Mass spectrometry analysis revealed 3 distinct subgroups of immunogenic proteins within these exoS: damage-associated molecular patterns (DAMPs), chaperones, and autoantigens. The involvement of endosomal-sorting complex required for transport proteins including ras-associated binding proteins7A, ras-associated binding protein GGTA, vacuolar protein sorting associated protein 45, vacuolar protein sorting associated protein 26B, and the tetraspanins CD9 and CD63, in exoS biogenesis was confirmed through immunoblotting. Next, we isolated similar exoS from the islet infusion bags of TPIAT recipients (N = 20). The exosomes from infusion bags exhibited higher DAMP (heat shock protein family A [Hsp70] member 1B and histone H2B) levels, particularly in the insulin-dependent TPIAT group. Additionally, elevated DAMP protein levels in islet infusion bag exosomes correlated with increased insulin requirements (P = .010) and higher hemoglobin A1c levels 1-year posttransplant. A deeper exploration into exoS functionality revealed their potential to activate monocytes via the toll-like receptor 3/7: DAMP axis. This stimulation resulted in the induction of inflammatory phenotypes marked by increased levels of CD68, CD80, inducible nitric oxide synthase, and cyclooxygenase-2. This activation mechanism may impact the successful engraftment of transplanted islets.

Utility of scores to predict alcohol use after liver transplant (lt): take them with a grain of salt.

BACKGROUND AIMS: The Sustained Alcohol use post-Liver Transplant (SALT) and the High-Risk Alcohol Relapse (HRAR) scores were developed to predict return to alcohol use after liver transplant (LT) for alcohol associated liver disease (ALD). METHODS: A retrospective analysis of deceased donor LT 10/2018 to 4/2022 was performed. All patients (pts) underwent careful pre-LT psychosocial evaluation. Data on alcohol use, substance abuse, prior rehabilitation, and legal issues were collected. Post-LT, all were encouraged to participate in rehabilitation programs and underwent interval phosphatidylethanol (PeTH) testing. Pts with ALD were stratified by < or > 6 month sobriety prior to listing. Those with <6 month were further stratified as acute alcoholic hepatitis (AH) by NIAAA criteria and non-AH. The primary outcome was utility of the SALT (<5 vs. ≥5) and HRAR (<3 vs. ≥3) scores to predict return to alcohol use (+PeTH) within 1 year after LT. RESULTS: Of the 365 LT, 86 had > 6 month sobriety and 85 had <6 month sobriety; 41 with AH and 44 non-AH. In those with AH, the mean time of abstinence to LT was 58 days, and 71% failed prior rehabilitation. Following LT, return to drinking was similar in the AH (24%) compared to <6M non-AH (15%) and >6M ALD (22%). Only 4% had returned to heavy drinking. The accuracy of both the SALT and HRAR scores to predict return to alcohol was low (accuracy 61-63%) with poor sensitivity (46% and 37%), specificity (67-68%), positive predictive value (22-26%) with moderate negative predictive value (NPV) (81-83%), respectively with higher NPVs (95%) in predicting return to heavy drinking. CONCLUSIONS: Both SALT and HRAR scores had good NPV in identifying patients at low risk for recidivism.

Single incision simultaneous liver kidney transplantation: Feasibility and outcomes.

BACKGROUND: Traditionally, simultaneous liver kidney transplantation (SLK) has been performed using a subcostal incision for the liver allograft and a lower abdominal incision for kidney transplantation (dual incision, DI). At our institution, we performed SLK using a single subcostal incision (SI). The aim of this study was to report the outcomes of single versus dual incisions for SLK. METHODS: A retrospective cohort study of consecutive SLK procedures performed at our center from January 2015 to April 2021 was performed. The demographic characteristics, complications, intraoperative findings, and complications after SI and DI were statistically compared. RESULTS: A total 37 SLK were performed (19 DI and 18 SI). The age and indications for transplantation were comparable between the two groups. Patient in SI group had significantly higher MELD score (27.0 ± 1.5 vs. 31.7 ± 1.5, p = .038). The cold ischemic time of kidney transplantation (599 ± 26 min vs. 447 ± 27 min, p < .001) and the total surgical time (508 ± 21 min vs. 423 ± 22 min, p = .008) were significantly shorter in the SI group. The incidence of complications and post-transplant kidney function was comparable between the groups. A slightly higher incidence of surgical site complications was noted in the DI group without any statistically significance (p = .178). CONCLUSIONS: Single-subcostal incision SLK is technically feasible and has comparable outcomes to dual-incision SLK. SI was associated with shorter cold ischemic time for kidney transplant, as well as shorter overall operative time.

Liver transplantation for post-COVID-19 cholangiopathy: A case series.

BACKGROUND: Post-COVID-19 cholangiopathy is an emerging cholestatic liver disease observed in patients recovering from severe COVID-19 infection. Its prognosis is poor, necessitating liver transplantation in some cases. This study aimed to investigate the outcomes of liver transplantation for post-COVID-19 cholangiopathy. METHODS: Seven patients who underwent liver transplantation for post-COVID-19 cholangiopathy at three institutions between 2020 and 2022 were included in this retrospective multi-center case series. RESULTS: At the time of initial COVID-19 infection, all patients developed acute respiratory distress syndrome, and six patients (86%) required ICU admission. Median time intervals from the initial COVID-19 diagnosis to the diagnosis of post-COVID-19 cholangiopathy and liver transplantation were 4 and 12 months, respectively. Four patients underwent living donor liver transplantation, and three patients underwent deceased donor liver transplantation. The median MELD score was 22 (range, 10-38). No significant intraoperative complications were observed. The median ICU and hospital stays were 2.5 and 12.5 days, respectively. One patient died due to respiratory failure 5 months after liver transplantation. Currently, the patient and graft survival rate is 86% at a median follow-up of 11 months. CONCLUSIONS: Liver transplantation is a viable option for patients with post-COVID-19 cholangiopathy with acceptable outcome. Timely identification of this disease and appropriate management, including evaluation for liver transplantation, are essential.

Targeting CXCR1/2 in the first multicenter, double-blinded, randomized trial in autologous islet transplant recipients.

Several cytokines and chemokines are elevated after islet infusion in patients undergoing total pancreatectomy with islet autotransplantation (TPIAT), including CXCL8 (also known as interleukin-8), leading to islet loss. We investigated whether use of reparixin for blockade of the CXCL8 pathway would improve islet engraftment and insulin independence after TPIAT. Adults without diabetes scheduled for TPIAT at nine academic centers were randomized to a continuous infusion of reparixin or placebo (double-blinded) for 7 days in the peri-transplant period. Efficacy measures included insulin independence (primary), insulin dose, hemoglobin A1c (HbA1c ), and mixed meal tolerance testing. The intent-to-treat population included 102 participants (age 39.5 ± 12.2 years, 69% female), n = 50 reparixin-treated, n = 52 placebo-treated. The proportion insulin-independent at Day 365 was similar in reparixin and placebo: 20% vs. 21% (p = .542). Twenty-seven of 42 (64.3%) in the reparixin group and 28/45 (62.2%) in the placebo group maintained HbA1c ≤6.5% (p = .842, Day 365). Area under the curve C-peptide from mixed meal testing was similar between groups, as were adverse events. In conclusion, reparixin infusion did not improve diabetes outcomes. CXCL8 inhibition alone may be insufficient to prevent islet damage from innate inflammation in islet autotransplantation. This first multicenter clinical trial in TPIAT highlights the potential for future multicenter collaborations.

Outcomes of short-duration antiviral prophylaxis for hepatitis C positive donor kidney transplants.

Trials describing 4- to 12-week courses of direct-acting antiviral drugs (DAAs) to treat hepatitis C virus (HCV) transmission from infected donors to uninfected kidney transplant recipients (D+/R- transplants) may be limited in "real-world" application by costs and delayed access to DAAs. We previously reported HCV transmission of 13% among D+/R- transplants with 2- to 4-day pangenotypic sofosbuvir/velpatasvir (SOF/VEL) perioperative prophylaxis, where one patient with HCV transmission was a nonresponder to first-line full-course DAA. Here, we report new data with a 7-day prophylaxis protocol (N = 50), as well as cumulative treatment and outcome data on all HCV D+/R- transplants (N = 102). Overall, nine patients (9/102; 9%; 95% CI: 5%-16%) developed HCV transmission, with a significant decline noted in the 7-day group (2/50; 4%; 95% CI: 0%-13%) compared with 2- to 4-day prophylaxis (7/52; 13%; 95% CI: 5%-25%). All patients with HCV transmission achieved sustained virologic response post full-course therapy (including one nonresponder from initial trial). A 1:1 matched analysis (N = 102) with contemporary HCV D-/R- transplants (controls) showed that although the pretransplant wait time was significantly shorter for D+/R- compared with D-/R- (mean: 1.8 vs. 4.4 years; p < .001), there were no differences in infections, rejection, development of de novo donor-specific antibody, or transplant outcomes up to 6 months of transplant.

The demise of islet allotransplantation in the United States: A call for an urgent regulatory update.

Islet allotransplantation in the United States (US) is facing an imminent demise. Despite nearly three decades of progress in the field, an archaic regulatory framework has stymied US clinical practice. Current regulations do not reflect the state-of-the-art in clinical or technical practices. In the US, islets are considered biologic drugs and "more than minimally manipulated" human cell and tissue products (HCT/Ps). In contrast, across the world, human islets are appropriately defined as "minimally manipulated tissue" and not regulated as a drug, which has led to islet allotransplantation (allo-ITx) becoming a standard-of-care procedure for selected patients with type 1 diabetes mellitus. This regulatory distinction impedes patient access to islets for transplantation in the US. As a result only 11 patients underwent allo-ITx in the US between 2016 and 2019, and all as investigational procedures in the settings of a clinical trials. Herein, we describe the current regulations pertaining to islet transplantation in the United States. We explore the progress which has been made in the field and demonstrate why the regulatory framework must be updated to both better reflect our current clinical practice and to deal with upcoming challenges. We propose specific updates to current regulations which are required for the renaissance of ethical, safe, effective, and affordable allo-ITx in the United States.

Ultra-short duration direct acting antiviral prophylaxis to prevent virus transmission from hepatitis C viremic donors to hepatitis C negative kidney transplant recipients.

We conducted an adaptive design single-center pilot trial between October 2017 and November 2018 to determine the safety and efficacy of ultra-short-term perioperative pangenotypic direct acting antiviral (DAA) prophylaxis for deceased hepatitis C virus (HCV)-nucleic acid test (NAT) positive donors to HCV negative kidney recipients (D+/R-). In Group 1, 10 patients received one dose of SOF/VEL (sofusbuvir/velpatasvir) pretransplant and one dose on posttransplant Day 1. In Group 2A (N = 15) and the posttrial validation (Group 2B; N = 25) phase, patients received two additional SOF/VEL doses (total 4) on Days 2 and 3 posttransplant. Development of posttransplant HCV transmission triggered 12-week DAA therapy. For available donor samples (N = 27), median donor viral load was 1.37E + 06 IU/mL (genotype [GT]1a: 70%; GT2: 7%; GT3: 23%). Overall viral transmission rate was 12% (6/50; Group 1:30% [3/10]; Group 2A:13% [2/15]; Group 2B:4% [1/25]). For the 6 viremic patients, 5 (83%) achieved sustained virologic response (3 with first-line DAA therapy; and two after retreatment with second-line DAA). At a median follow-up of 8 months posttransplant, overall patient and allograft survivals were 98%, respectively. The 4-day strategy reduced viral transmission to 7.5% (3/40; 95% confidence interval [CI]: 1.8%-20.5%) and could result in avoidance of prolonged posttransplant DAA therapy for most D+/R - transplants.

The role of total pancreatectomy with islet autotransplantation in the treatment of chronic pancreatitis: A report from the International Consensus Guidelines in chronic pancreatitis.

BACKGROUND: Advances in our understanding of total pancreatectomy with islet autotransplantation (TPIAT) have been made. We aimed to define indications and outcomes of TPIAT. METHODS: Expert physician-scientists from North America, Asia, and Europe reviewed the literature to address six questions selected by the writing group as high priority topics. A consensus was reached by voting on statements generated from the review. RESULTS: Consensus statements were voted upon with strong agreement reached that (Q1) TPIAT may improve quality of life, reduce pain and opioid use, and potentially reduce medical utilization; that (Q3) TPIAT offers glycemic benefit over TP alone; that (Q4) the main indication for TPIAT is disabling pain, in the absence of certain medical and psychological contraindications; and that (Q6) islet mass transplanted and other disease features may impact diabetes mellitus outcomes. Conditional agreement was reached that (Q2) the role of TPIAT for all forms of CP is not yet identified and that head-to-head comparative studies are lacking, and that (Q5) early surgery is likely to improve outcomes as compared to late surgery. CONCLUSIONS: Agreement on TPIAT indications and outcomes has been reached through this working group. Further studies are needed to answer the long-term outcomes and maximize efforts to optimize patient selection.

Impact of belatacept conversion on kidney transplant function, histology, and gene expression - a single-center study.

Prior studies on belatacept conversion from calcineurin inhibitor (CNI) have been limited by an absence of postconversion surveillance biopsies that could underestimate subclinical rejection, or a case-controlled design. A total of 53 adult patients with allograft dysfunction underwent belatacept conversion (median: 6 months) post-transplant. At a median follow-up = 2.5 years, patient survival was 94% with a death-censored graft survival of 85%. Seven (13%) patients had acute rejection (including 3 subclinical) at median 6 months postconversion. Overall, eGFR improved (P = <0.001) from baseline = 31±15 to 40.2 ± 17.6 ml/min/1.73m2 by 6 months postconversion, but then stayed stable. This improvement was also observed (P < 0.001) in comparison with a propensity matched control cohort on CNI, where eGFR stayed stable (mean ~ 32ml/min/1.72m2 ) over 2-year follow-up. Patients converted < 6 months post-transplant were more likely to have a long-term improvement in kidney function. Paired gene expression analysis of 30 (of 53) consecutive pre- and postconversion surveillance biopsies did not reveal changes in inflammation/acute injury; although atrophy-fibrosis score worsened (mean = 0.28 to 0.44; P = 0.005). Thus, improvement in renal function with belatacept conversion occurred early and then sustained in comparison with controls where renal function remained unchanged overtime. We were unable to show molecular signals that could be related to CNI administration and regressed after withdrawal.

Obesity does not significantly impact outcomes following simultaneous liver kidney transplantation: review of the UNOS database - a retrospective study.

Simultaneous liver kidney transplantation (SLK) is the only curative option for patients with combined end stage liver and kidney disease. With the global obesity epidemic, an increasing number of obese patients are in need of SLK. However, the impact of pre-transplant obesity on outcomes after SLK is unknown. An analysis of the United States OPTN registry (Oct 1987 - June 2016) identified 7205 SLK transplants. Of these, 1677 patients were overweight/obese (OW, BMI 30-39) and 183 were morbidly obese (MO, BMI ≥40). 29% of patients had NASH in the MO group versus 16.4% and 4.7% in the OW and normal weight (NW) groups, respectively. The 1, 3 and 5 year overall patient survival, kidney and liver graft survivals were comparable between the three groups. Numerically higher rates of acute kidney rejection were reported in the MO group at 1 year [12.73%, 8.59%, and 10.05% for MO, OW and NW, respectively (P = 0.22)]. Multivariate analysis identified diagnosis of hepatitis C, donor age, diabetes mellitus, and delayed kidney transplant function but not BMI as risk factors for poor patient and both liver and kidney graft survival. Based on these findings, obesity should not be a contraindication for SLK even for patients with BMIs ≥ 40.

Coronary artery disease in decompensated patients undergoing liver transplantation evaluation.

Coronary artery disease (CAD) is an important contributor to morbidity and mortality in patients undergoing liver transplantation (LT). However, the current literature is limited by sampling bias and nondefinitive assessment of CAD. The current study examines the prevalence of CAD via per protocol coronary angiography and its relationship to etiology of liver disease in patients undergoing liver transplantation evaluation (LTE). Data on 228 patients were prospectively collected who had coronary angiography as part of LTE between 2011 and 2014. Coronary angiography was done in all patients age ≥50 years or with CAD risk factors. CAD was defined as any coronary artery stenosis, whereas stenosis ≥ 70% in distribution of 1 or 3 major coronary arteries was considered as single- or triple-vessel disease. CAD was detected in 36.8% of patients, with the highest prevalence among nonalcoholic steatohepatitis (NASH) patients with cirrhosis (52.8%). Prevalence of single-vessel disease was higher among patients with NASH compared with hepatitis C virus (HCV) and alcoholic cirrhosis (15.1% versus 4.6% versus 6.6%; P = 0.02). Similarly, patients with NASH were more likely to have triple-vessel disease when compared with HCV and alcoholic cirrhosis (9.4% versus 0.9% versus 0%; P = 0.001). While adjusting for traditional risk factors for CAD, only NASH as etiology of liver disease remained significantly associated with CAD. Complications from diagnostic coronary angiography or percutaneous coronary intervention were low (2.6%). In conclusion, patients undergoing LTE have a high prevalence of CAD, which varies widely depending on etiology of liver cirrhosis. The procedural complications from coronary angiography are low. Liver Transplantation 24 333-342 2018 AASLD.

Risk factors for early readmission after total pancreatectomy and islet auto transplantation.

BACKGROUND: Little published data exist examining causes of hospital readmission following total pancreatectomy with islet autotransplantation (TPIAT). METHODS: A retrospective analysis was performed of a prospectively collected institutional TPIAT database. Primary outcome was unplanned readmission to the hospital within 30 days from discharge. Reasons and risk factors for readmission as well as islet function were evaluated and compared by univariate and multivariate analysis. RESULTS: 83 patients underwent TPIAT from 2006 to 2014. 21 patients (25.3%) were readmitted within 30 days. Gastrointestinal problems (52.4%) and surgical site infection (42.8%) were the most common reasons for readmission. Initial LOS and reoperation were risk factors for early readmission. Patients with delayed gastric emptying (DGE) were three times more likely to get readmitted. In multivariate analysis, patients undergoing pylorus preservation surgery were nine times more likely to be readmitted than the antrectomy group. CONCLUSION: Early readmission after TPIAT is common (one in four patients), underscoring the complexity of this procedure. Early readmission is not detrimental to islet graft function. Patients undergoing pylorus preservation are more likely to get readmitted, perhaps due to increased incidence of delayed gastric emptying. Decision for antrectomy vs. pylorus preservation needs to be individualized.

A study of the clinical utility of a 20-minute secretin-stimulated endoscopic pancreas function test and performance according to clinical variables.

BACKGROUND AND AIMS: Direct pancreas juice testing of bicarbonate, lipase, or trypsin after stimulation by secretin or cholecystokinin is used to determine exocrine function, a surrogate for diagnosing chronic pancreatitis (CP). Endoscopic pancreas function tests (ePFTs), where a peak bicarbonate concentration (PBC) ≥80 mEq/L in pancreas juice is considered normal, are now used more frequently. In this ePFT, aspirates start 35 minutes after secretin administration because pancreas output peaks 30 minutes after secretagogue administration. The performance of ePFT in a cohort of patients with a presumptive diagnosis of CP referred to a pancreas clinic for consideration of an intervention including total pancreatectomy and islet autotransplantation was studied, compared with EUS, ERCP, histology, and consensus diagnosis. The effect of sedation, narcotic use, aspirate volume, body mass index, age, and proton pump inhibitors (PPIs) on test performance is reported. METHODS: After a test dose, synthetic human secretin was administered intravenously, and 30 minutes later sedation was achieved with midazolam and fentanyl or propofol. A gastroscope was advanced to the major papilla where 4 continuous aspiration samples were performed at 5-minute intervals in sealed bottles. PBC ≥80 mEq/L was normal. RESULTS: Eighty-one patients had ePFTs from August 2010 through October 2015. Twenty-seven patients (33%) were diagnosed with CP. Eighteen of the 27 patients with CP and 1 of the 54 patients without CP had an abnormal ePFT, producing a sensitivity of 66% (95% CI, 46.0-83.5), specificity 98% (95% CI, 90.1-99.9), positive predictive value 94.7% (95% CI, 74-99.9), and negative predictive value 85.5% (95% CI, 74.2-93.1). ERCP and PBC concordance was generally poor, but none of the patients without CP had major EUS changes, and only 3 patients with a PBC <80 mEq/L had a normal EUS. The PBC was affected by narcotics and PPI use. CONCLUSION: A 20-minute ePFT after secretin administration had a marginal sensitivity for diagnosis of CP. The diagnosis of CP should not rely on a single study and certainly not a PFT. The duodenal aspirate volume did not correlate with the PBC, which contrasts with current secretin-enhanced MRCP knowledge; therefore, further studies on this subject are warranted. Neither type of sedation, BMI, nor age affected test performance. Narcotics and PPIs may affect the PBC, so borderline results should be interpreted with caution in these groups.

Long-term outcomes and transmission rates in hepatitis C virus-positive donor to hepatitis C virus-negative kidney transplant recipients: Analysis of United States national data.

The use of kidneys from hepatitis C virus (HCV)-positive (D+) deceased donors for HCV-negative recipients (R-) might increase the donor pool. We analyzed the national Organ Procurement and Transplant Network (OPTN) registry from 1994 to 2014 to compare the outcomes of HCV D+/R- (n = 421) to propensity-matched HCV-negative donor (D-)/R- kidney transplants, as well as with waitlisted patients who never received a transplant, in a 1:5 ratio (n = 2105, per matched group). Both 5-year graft survival (44% vs 66%; P < .001) and patient survival (57% vs 79%; P < .001) were inferior for D+/R- group compared to D-/R-. Nevertheless, 5-year patient survival from the time of wait listing was superior for D+/R- when compared to waitlisted controls (68% vs 43%; P < .001). Of the 126 D+/R- with available post-transplant HCV testing, HCV seroconversion was confirmed in 62 (49%), likely donor-derived. Five-year outcomes were similar between D+/R- that seroconverted vs D+/R- that did not (n = 64). Our analysis shows inferior outcomes for D+/R- patients although detailed data on pretransplant risk factors was not available. Limited data suggest that HCV transmission occurred in half of HCV D+/R- patients, although this might not have been the primary factor contributing to the poor observed outcomes.

Essential phospholipids prevent islet damage induced by proinflammatory cytokines and hypoxic conditions.

BACKGROUND: The pancreatic islet damage that occurs through an inflammatory response and hypoxia after infusion is a major hurdle in islet transplantation. Because essential phospholipids (EPL) have been shown to exhibit anti-inflammatory properties in liver disease, we analysed their protective effect on islets in inflammatory or hypoxic conditions. METHODS: We evaluated the viability of mouse and human islets cultured with cytokines or in hypoxic conditions for 48 h and measured cytokine expression in islets by quantitative polymerase chain reaction. We then employed an in vivo mouse assay, transplanting a marginal dose of human islets treated with or without EPL into the subcapsule of the kidney in diabetic nude mice and determining the cure rate. RESULTS: The viability of mouse and human islets damaged by cytokines was significantly improved by supplementation of EPL in the culture (p = 0.003 and <0.001 for mouse and human islets respectively). EPL significantly inhibited intracellular expression of IL-1ß and IL-6 in cytokine-damaged human islets (p < 0.001). The viability of human islets in hypoxic conditions was significantly better when treated with EPL (p < 0.001). In the in vivo mouse assay, the EPL-treated islet group had a higher cure rate than the untreated control, with marginal statistical significance (75 and 17% respectively, p = 0.07). CONCLUSIONS: EPL could be a potent agent to protect islets from inflammatory and hypoxic conditions after isolation procedures. Further studies to clarify the effect of EPL in islet transplantation are warranted.

Improving allogeneic islet transplantation by suppressing Th17 and enhancing Treg with histone deacetylase inhibitors.

Islet transplantation is a new treatment for achieving insulin independence for patients with severe diabetes. However, major drawbacks of this treatment are the long graft survival, the necessity for immunosuppressive drugs, and the efficacy of transplantation. Donor-specific transfusion (DST) has been shown to reduce rejection after organ transplantation, potentially through enhanced regulatory T-cell (Treg) activity. However, recent findings have shown that activated Treg can be converted into Th17 cells. We focused on histone deacetylase inhibitors (HDACi) because it was reported that inhibition of HDAC activity prevented Treg differentiation into IL17-producing cells. We therefore sought to enhance Treg while suppressing Th17 cells using DST with HDACi to prolong graft survival. To stimulate Treg by DST, we used donor splenocytes. In DST with HDACi group, Foxp3 mRNA expression and Treg population increased in the thymus and spleen, whereas Th17 population decreased. qPCR analysis of lymphocyte mRNA indicated that Foxp3, IL-10, and TGF-b expression increased. However, interleukin 17a, Stat3 (Th17), and IFN-g expression decreased in DST + HDACi group, relative to DST alone. Moreover, DST treated with HDACi prolonged graft survival relative to controls in mice islet transplantation. DST with HDACi may therefore have utility in islet transplantation.