Massimo Venturini

Kidney Function after Islet Transplant Alone in Type 1 Diabetes: Impact of Immunosuppressive Therapy on Progression of Diabetic Nephropathy

OBJECTIVE—Islet transplantation alone is an alternative for the replacement of pancreatic endocrine function in patients with type 1 diabetes. The aim of our study was to assess the impact of the Edmonton immunosuppressive protocol (tacrolimus-sirolimus association) on kidney function. RESEARCH DESIGN AND METHODS—Nineteen patients with type 1 diabetes and metabolic instability received islet transplantation alone and immunosuppressive therapy according to the Edmonton protocol. Serum creatinine (sCr), creatinine clearance (CrCl), and 24-h urinary protein excretion (UPE) were assessed at baseline and during a follow-up of 339 patient-months. RESULTS— After islet transplantation we observed 1) sCr within the normal range in all but two patients in whom sCr increased immediately after islet transplantation, and despite withdrawal of immunosuppression, patients progressed to end-stage renal disease (ESRD); 2) CrCl remained within the normal range for those patients who had normal baseline values and decreased, progressing to ESRD in two patients with a decreased baseline CrCl; and 3) 24-h UPE worsened (>300 mg/24 h) in four patients. In the two patients who progressed to ESRD, the worsening of 24-h UPE occurred immediately after islet transplantation. In one patient 24-h UPE worsening occurred at 18 months, and, after withdrawal of immunosuppression, it returned to the normal range. In another patient 24-h UPE increased at 24 months and remained stable while immunosuppression was continued. CONCLUSIONS—In type 1 diabetic patients receiving islet transplantation alone, the association of tacrolimus and sirolimus should be used only in patients with normal kidney function. Alternative options for immunosuppressive treatment should be considered for patients with even a mild decrease of kidney function.

Hemorrhage from a Right Hepatic Artery Pseudoaneurysm: Endovascular Treatment with a Coronary Stent-Graft

PURPOSE To report a novel case demonstrating the successful endovascular treatment of a right hepatic artery pseudoaneurysm using a balloon-expandable coronary stent-graft. CASE REPORT A 60-year-old woman underwent surgical treatment for a Klatskin tumor, but her postoperative course was complicated by serious blood loss. An emergent celiac angiogram through a right transfemoral approach demonstrated a small iatrogenic pseudoaneurysm in the proximal right hepatic artery. A 7-F guiding catheter was positioned at the origin of the celiac trunk, and a Jostent coronary stent-graft mounted on a 2.7-F, 4-mm x 30-mm balloon catheter was successfully placed across the aneurysm neck. The final angiogram demonstrated total exclusion of the pseudoaneurysm with preservation of the arterial lumen. The hemodynamic condition of the patient became stable. At 12-month follow-up, duplex scanning confirmed regular right hepatic artery patency and absence of thrombotic tissue or signs of infection around the stent-graft. CONCLUSION For hepatic artery pseudoaneurysms, endovascular repair using small covered stents may be a viable alternative to transcatheter embolization. The use of coronary instruments facilitates treatment of vascular lesions in small caliber visceral vessels.

Early increase of retinal arterial and venous blood flow velocities at color Doppler imaging in brittle type 1 diabetes after islet transplant alone.

Little information is currently available about the role of islet transplantation alone (ITA) on the retinal microcirculation. Our purpose was to investigate with color-Doppler-imaging the effect of ITA after one year on the blood flow velocities of central retinal artery and vein. Central retinal arteries and veins of both eyes of 10 ITA patients were evaluated with color-Doppler-imaging before and one year after transplant. Peak systolic velocity (psv), end diastolic velocity (edv) for arteries and maximum velocity (maxv), minimum velocity (minv) for veins were recorded and compared with a control group of type 1 diabetic patients. At one year, a statistically significant increase of blood flow velocities of central retinal arteries (psv: 6.09±0.46 vs. 10.12±1.20 cm/s, P=0.01) and veins (maxv: 3.12±0.28 vs. 6.12±1.00 cm/s, P=0.01) was found only in the ITA patients. An early, significant increase of arterial and venous retinal blood flow velocities was found after ITA.

Value of abdominal sonography and MR imaging at 0.5 T in preoperative detection of pancreatic insulinoma: a comparison with dynamic CT and angiography

Abstract.Background: Abdominal sonography, computed tomography (CT), angiography, and magnetic resonance (MR) imaging are the most widely used modalities for preoperative localization of insulinomas. CT and angiography are generally considered the techniques of reference, and the role of sonography and MR imaging in these patients is controversial. The purpose of this study was to compare these four modalities in a group of patients with pancreatic insulinoma and determine an effective radiological approach to this disease. Methods: Twenty-eight patients with clinical and biochemical signs of pancreatic insulinoma underwent abdominal sonography, MR imaging at 0.5 T (spin echo technique), bolus dynamic CT, and digital subtraction angiography. Examinations were evaluated independently for the presence, size, and location of the lesions; preoperative diagnoses were compared with surgical findings based on palpation and intraoperative sonography. Tumoral vascularity was histologically graded. Sensitivities of the four imaging techniques were calculated and compared with the size, location, and vascularity of the tumors. Detection rates of combined techniques were finally determined. Results: At surgery, 29 lesions in the 28 patients were found (range = 0.8–4.3 cm, average = 1.65 cm). Sensitivities of abdominal sonography, MR imaging, CT, and angiography were 79.3%, 65.5%, 44.8%, and 69% respectively. Correct localization of tumor was achieved in 96.6% of cases by a combination of sonography and MR imaging and in 72.4% of cases by using CT with angiography. Conclusion: In our experience, sonography and MR imaging performed well in the preoperative detection of pancreatic insulinoma. Therefore, we believe that the combination of abdominal sonography and MR imaging may represent the first radiological approach in clinically suspected insulinomas and that CT and angiography should be reserved for negative and/or doubtful cases.

Intra-arterial transplantation of HLA-matched donor mesoangioblasts in Duchenne muscular dystrophy

Intra‐arterial transplantation of mesoangioblasts proved safe and partially efficacious in preclinical models of muscular dystrophy. We now report the first‐in‐human, exploratory, non‐randomized open‐label phase I–IIa clinical trial of intra‐arterial HLA‐matched donor cell transplantation in 5 Duchenne patients. We administered escalating doses of donor‐derived mesoangioblasts in limb arteries under immunosuppressive therapy (tacrolimus). Four consecutive infusions were performed at 2‐month intervals, preceded and followed by clinical, laboratory, and muscular MRI analyses. Two months after the last infusion, a muscle biopsy was performed. Safety was the primary endpoint. The study was relatively safe: One patient developed a thalamic stroke with no clinical consequences and whose correlation with mesoangioblast infusion remained unclear. MRI documented the progression of the disease in 4/5 patients. Functional measures were transiently stabilized in 2/3 ambulant patients, but no functional improvements were observed. Low level of donor DNA was detected in muscle biopsies of 4/5 patients and donor‐derived dystrophin in 1. Intra‐arterial transplantation of donor mesoangioblasts in human proved to be feasible and relatively safe. Future implementation of the protocol, together with a younger age of patients, will be needed to approach efficacy.

Extending indications for islet autotransplantation in pancreatic surgery.

Objective: To assess metabolic and oncologic outcomes of islet autotransplantation (IAT) in patients undergoing pancreatic surgery for either benign or malignant disease. Background: IAT is performed to improve glycemic control after extended pancreatectomy, almost exclusively in patients with chronic pancreatitis. Limited experience is available for other indications or in patients with pancreatic malignancy. Methods: In addition to chronic pancreatitis, indications for IAT were grade C pancreatic fistula (treated with completion or left pancreatectomy, as indicated); total pancreatectomy as an alternative to high-risk anastomosis during pancreaticoduodenectomy; and distal pancreatectomy for benign/borderline neoplasm of pancreatic body-neck. Malignancy was not an exclusion criterion. Metabolic and oncologic follow-up is presented. Results: From November 2008 to June 2012, 41 patients were candidates to IAT (accounting for 7.5% of all pancreatic resections). Seven of 41 did not receive transplantation for inadequate islet mass (4 pts), patient instability (2 pts), or contamination of islet culture (1 pt). IAT-related complications occurred in 8 pts (23.5%): 4 bleeding, 3 portal thromboses (1 complete, 2 partial), and 1 sepsis. Median follow-up was 546 days. Fifteen of 34 patients (44%) reached insulin independence, 16 patients (47%) had partial graft function, 2 patients (6%) had primary graft nonfunction, and 1 patient (3%) had early graft loss. Seventeen IAT recipients had malignancy (pancreatic or periampullary adenocarcinoma in 14). Two of them had already liver metastases at surgery, 13 were disease-free at last follow-up, and none of 2 patients with tumor recurrence developed metastases in the transplantation site. Conclusions: Although larger data are needed to definitely exclude the risk of disease dissemination, the present study suggests that IAT indications can be extended to selected patients with neoplasm.

Risks and benefits of transplantation in the cure of type 1 diabetes: whole pancreas versus islet transplantation. A single center study.

BACKGROUND Pancreas and islet transplantation are the only available options to replace beta-cell function in patients with type 1 diabetes. Great variability in terms of rate of success for both approaches is reported in the literature and it is difficult to compare the respective risks and benefits. OBJECTIVES The aim of this study was to analyze risks and benefits of pancreas transplantation alone (PTA) and islet transplantation alone (ITA) by making use of the long-term experience of a single center where both transplantations are performed. We focused on the risks and benefits of both procedures, with the objective of better defining indications and providing evidence to support the decision-making process. The outcomes of 33 PTA and 33 ITA were analyzed, and pancreas and islet function (i.e., insulin independence), perioperative events, and long-term adverse events were recorded. RESULTS We observed a higher rate of insulin independence in PTA (75%) versus ITA (59%), with the longer insulin independence among PTA patients receiving tacrolimus. The occurrence of adverse events was higher for PTA patients in terms of hospitalization length and frequency, re-intervention for surgical and immunological acute complications, CMV reactivation, and other infections. CONCLUSIONS In conclusion, these results support the practice of listing patients for PTA when the metabolic control and the progression of chronic complications require a rapid normalization of glucose levels, with the exception of patients with cardiovascular disease, because of the high surgical risks. ITA is indicated when replacement of beta-cell mass is needed in patients with a high surgical risk.

Improved function of circulating angiogenic cells is evident in type 1 diabetic islet-transplanted patients

Circulating angiogenic cells (CACs) are vascular‐committed bone marrow‐derived cells that are dysfunctional in type 1 diabetes (T1D). Here we studied whether restoration of normoglycemia following islet transplantation is associated with better CAC function. We carried out a cross‐sectional study of 18 T1D patients, 14 insulin‐independent islet‐transplanted patients (ITA) and 14 healthy controls (C) evaluating in vivo and in vitro CACs viability and function. We found that the percentage of CACs in vivo did not differ among the three groups while the number of CAC colonies obtained from T1D, but not from ITA, was reduced compared to C (C = 7.3 ± 1.9, T1D = 0.9 ± 0.4 and ITA = 4.7 ± 1.9; p < 0.05 T1D vs. all). In vitro CAC migration/differentiation were similar, while in vivo an improved angiogenic ability of ITA compared to T1D was shown (capillary density: C = 93.5 ± 22.1, T1D = 19.2 ± 2.8 and ITA = 44.0 ± 10.5, p < 0.05 T1D vs. all). Increased apoptosis and lesser IL‐8 secretion were evident in CACs obtained from T1D compared to C and ITA. in vitro addition of anti‐hIL‐8 reduced the number of colonies obtained from C. Finally, T1D, but not ITA, had a lower endothelial‐dependent dilatation (EDD) compared with C. These data suggest that CAC function is altered in T1D and may be improved after islet transplantation.

Transarterial Chemoembolization with Drug-eluting Beads Preloaded with Irinotecan as a First-Line Approach in Uveal Melanoma Liver Metastases: Tumor Response and Predictive Value of Diffusion-weighted MR Imaging in Five Patients

Five patients with uveal melanoma metastatic to the liver (two to five lesions per patient) were prospectively enrolled and treated with transarterial chemoembolization with drug-eluting beads preloaded with irinotecan as a first-line therapy. An overall response rate of 80% was obtained per Response Evaluation Criteria In Solid Tumors. All patients were alive after mean follow-up durations of 10.6 months and 16.3 months, respectively, after the first treatment and the diagnosis of liver metastasis. The apparent diffusion coefficient values obtained by diffusion-weighted magnetic resonance imaging were significantly lower in lesions that showed a response. These findings are very promising and can constitute the background for further studies involving larger cohorts of patients.

Wiskott–Aldrich syndrome protein deficiency in natural killer and dendritic cells affects antitumor immunity

Wiskott–Aldrich syndrome (WAS) is a primary immunodeficiency caused by reduced or absent expression of the WAS protein (WASP). WAS patients are affected by microthrombocytopenia, recurrent infections, eczema, autoimmune diseases, and malignancies. Although immune deficiency has been proposed to play a role in tumor pathogenesis, there is little evidence on the correlation between immune cell defects and tumor susceptibility. Taking advantage of a tumor‐prone model, we show that the lack of WASP induces early tumor onset because of defective immune surveillance. Consistently, the B16 melanoma model shows that tumor growth and the number of lung metastases are increased in the absence of WASP. We then investigated the in vivo contribution of Was−/− NK cells and DCs in controlling B16 melanoma development. We found fewer B16 metastases developed in the lungs of Was−/− mice that had received WT NK cells as compared with mice bearing Was−/− NK cells. Furthermore, we demonstrated that Was−/− DCs were less efficient in inducing NK‐cell activation in vitro and in vivo. In summary, for the first time, we demonstrate in in vivo models that WASP deficiency affects resistance to tumor and causes impairment in the antitumor capacity of NK cells and DCs.