Martin Wijkstrom

• MD
• University of Pittsburgh

Background In total pancreatectomy with islet autotransplantation (TPIAT), a greater number of islets transplanted produces more favorable outcomes. We aimed to determine predictors of islet isolation outcomes. Methods We investigated factors associated with islet isolation outcomes expressed as islet number (IN), islet equivalents (IEQ; standardi...

Background: Renal artery aneurysm (RAA) is a rare condition that involves dilation of all layers of the arterial wall of the renal artery. The risk of rupture is rare, but intervention is recommended for larger aneurysms. Surgical decision-making regarding live donor renal transplantation (LDRT) centers around safety for the living donor, and late...

Background and AimsTotal pancreatectomy with islet autotransplantation (TPIAT) can relieve pain for individuals with acute recurrent or chronic pancreatitis. However, TPIAT may increase the risk of poor nutritional status with complete exocrine pancreatic insufficiency, partial duodenectomy, and intestinal reconstruction. Our study's objective was...

VX-880 is an investigational allogeneic stem cell-derived, fully differentiated, pancreatic islet cell replacement therapy being evaluated in a phase 1/2 clinical trial in patients with T1D and impaired hypoglycemic awareness and severe hypoglycemia. The phase 1/2 trial has three parts: Part A in which 2 patients are enrolled sequentially and recei...

As a population, living kidney donors have a longer life expectancy than the general population. This is generally thought to be an artifact of selection, as only healthy individuals are allowed to donate, and the operative mortality and risk of subsequent renal failure are very low. However, there may also be an additional benefit to the process,...

Background: A paucity of research regarding the psychosocial outcomes after TPIAT exists. Methods: Adults (>18 years), adolescents (13-18 years), and children (5-12 years) with their parents were administered questionnaires at the time of evaluation for TPIAT and 1-year postsurgery to assess psychosocial outcomes. Results: A total of 13 adults...

Chronic pancreatitis (CP) is a complex inflammatory disorder with numerous associated genetic and environmental risk factors. The most distressing characteristic of CP is recalcitrant pain, often requiring surgical resection including total pancreatectomy with islet autotransplantation (TPIAT). We studied 5 consented subjects undergoing pancreatic...

Background Total pancreatectomy with islet autotransplantation (TPIAT) is a viable option for treating debilitating recurrent acute pancreatitis (RAP) and chronic pancreatitis (CP) in adults and children. No data is currently available regarding variation in approach to operation. Methods We evaluated surgical techniques, islet isolation and infus...

Due to shortage of donor, kidney transplants (KTs) from donors with acute kidney injury (AKI) are expanding. Although previous studies comparing clinical outcomes between AKI and non-AKI donors in KTs have shown comparable results, data on high-volume analysis of KTs outcomes with AKI donors are limited. This study aimed to analyze the selection tr...

Objectives: Smoking and alcohol use are risk factors for acute and chronic pancreatitis, and their role on anxiety, depression, and opioid use in patients who undergo total pancreatectomy and islet autotransplantation (TPIAT) is unknown. Methods: We included adults enrolled in the Prospective Observational Study of TPIAT (POST). Measured variabl...

The Food and Drug Administration (FDA) has been regulating human islets for allotransplantation as a biologic drug in the US. Consequently, the requirement of a biological license application (BLA) approval before clinical use of islet transplantation as a standard of care procedure has stalled the development of the field for the last 20 years. He...

The use of kidneys donated after circulatory death (DCD) provides an invaluable expansion of the organ supply for transplantation. Here we investigated the effect of DCD on fibrotic changes on 1-year post-transplant surveillance kidney allograft biopsy. Recipients of a deceased donor kidney transplant between 2013 and 2017 at a single institution,...

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 independen...

Circulating microRNAs (miRNAs) can be biomarkers for diagnosis and progression of several pathophysiological conditions. In a cohort undergoing total pancreatectomy with islet autotransplantation (TPIAT) from the multicenter Prospective Observational Study of TPIAT (POST), we investigated associations between a panel of circulating miRNAs (hsa-miR-...

We are writing with great concern about the consequences of applying drug related regulations to allogeneic islets (allo‐islets). Currently, the Food and Drugs Administration (FDA) is reviewing a Biologics License Application (BLA) for the isolation of allogenic islets which, if approved, will effectively confer marketing rights to a private, for‐p...

Enteric hyperoxaluria (EH) is a known complication of Roux-en-Y gastric bypass (RYGB) and can lead to nephrolithiasis, oxalate-induced nephropathy, and end-stage renal disease. Recurrent EH-induced renal impairment has been reported after kidney transplantation and may lead to allograft loss. EH occurs in up to one quarter of patients following mal...

Total pancreatectomy with autologous islet cell transplant (TPAIT) is a treatment option for patients suffering from chronic or recurrent acute pancreatitis, providing benefits of pain relief, enhanced quality of life, and prevention of brittle type 3c diabetes [1]. While surgical procedure requires extensive dissection and elevates risk of bleedin...

Purpose of Review Pancreas and islet cell transplantation are the only treatment modalities that can restore euglycemia and allow freedom from hypoglycemic events. Transplantation for diabetes has decreased in the USA over the last 6 years due to several factors. Reasons for this and possible future paths will be explored. Recent Findings Clinical...

Background and aims Many patients undergoing total pancreatectomy with islet autotransplant (TPIAT) for severe, refractory chronic pancreatitis or recurrent acute pancreatitis have a history of endoscopic retrograde cholangiopancreatography (ERCP). Using data from the multicenter POST (Prospective Observational Study of TPIAT) cohort, we aimed to d...

Background The identification of genetic risk factors for chronic pancreatitis, such as PRSS1, CFTR and SPINK1, provides the opportunity to define key pathologic hallmarks and etiologic-specific changes. For example, pancreata from PRSS1 and CFTR patients exhibit progressive lipomatous atrophy without significant fibrosis. Considering the pathology...

The immunologic barriers to successful xenotransplantation are related to the presence of natural anti-pig antibodies in humans and nonhuman primates that bind to antigens expressed on the transplanted pig organ (the most important of which is galactose-α1,3-galactose [Gal]) and activate the complement cascade, which results in rapid destruction of...

Transplantation of kidneys from deceased donors with acute kidney injury (AKI) can expand the donor pool. We investigated the effect of donor AKI on renal function and chronic changes on protocol biopsies at 1‐year post‐transplant. Donor AKI was defined according to Acute Kidney Injury Network (AKIN) criteria. Between 2013 and 2017, 333 kidneys wer...

Objectives: A selective therapy for pancreatitis is total pancreatectomy and islet autotransplantation. Outcomes and geographical variability of patients who had total pancreatectomy (TP) alone or total pancreatectomy with islet autotransplantation (TPIAT) were assessed. Methods: Data were obtained from the Healthcare Cost and Utilization Projec...

Myeloid-derived suppressor cells (MDSC) are a heterogenous population of immunosuppressive myeloid cells now considered important immune regulatory cells in diverse clinical conditions, including cancer, chronic inflammatory disorders and transplantation. In rodents, MDSC administration can inhibit graft-versus-host disease lethality and enhance or...

Background: Recent studies have reported a significant decrease in wound problems and hospital stay in obese patients undergoing renal transplantation by robotic-assisted minimally invasive techniques with no difference in graft function. Objective: Due to the lack of cost-benefit studies on the use of robotic-assisted renal transplantation vers...

Background/objectives: Total pancreatectomy with islet autotransplantation (TPIAT) is considered for managing chronic pancreatitis in selected patients when medical and endoscopic interventions have not provided adequate relief from debilitating pain. Although more centers are performing TPIAT, we lack large, multi-center studies to guide decision...

Background: We investigated in vitro whether HLA-highly-sensitized patients with end-stage renal disease (ESRD) will be disadvantaged immunologically after a genetically-engineered pig kidney transplant. Methods: Blood was drawn from patients with a cPRA 99-100% (Gp1, n=10) or cPRA 0% (Gp2, n=12), and from healthy volunteers (Gp3, n=10). Serum I...

Inflammation is known to preclude tolerance after transplantation. We have previously shown that systemic inflammation in xenograft recipients (SIXR) precedes activation of coagulation in the absence of T cell responses. Accordingly, SIXR may amplify innate and adaptive immune responses against xenografts after pig-to-primate xenotransplantation, e...

Background: Genetically engineered pigs could provide a source of kidneys for clinical transplantation. The two longest kidney graft survivals reported to date have been 136 and 310 days, but graft survival >30 days has been unusual until recently. Methods: Donor pigs (n=4) were on an α1,3-galactosyltransferase gene-knockout (GTKO)/human complem...

Background: Some patients with acute or acute-on-chronic hepatic failure die before a suitable human liver allograft becomes available. Encouraging results have been achieved in such patients by the transplantation of human hepatocyte progenitor cells from fetal liver tissue. The aim of the study was to explore survival of hepatocytes from genetic...

Systemic administration of autologous regulatory dendritic cells (DCreg; unpulsed or pulsed with donor antigen [Ag]), prolongs allograft survival and promotes transplant tolerance in rodents. Here, we demonstrate that nonhuman primate (NHP) monocyte-derived DCreg pre-loaded with cell membrane vesicles from allogeneic PBMC, induce T cell hyporespons...

Several groups have reported extended survival of genetically-engineered pig organs in nonhuman primates, varying from almost 10 months for life-supporting kidney grafts and >2 years for nonlife-supporting heart grafts to less than 1 month for life-supporting liver and lung grafts. We have attempted to define groups of patients who may not have an...

There are >100,000 patients waiting for kidney transplants in the United States and a vast need worldwide. Xenotransplantation, in the form of the transplantation of kidneys from genetically engineered pigs, offers the possibility of overcoming the chronic shortage of deceased and living human donors. These genetic manipulations can take the form o...

Transplantation of islets into the gastric submucosal space (GSMS) has several advantages (e.g., avoidance of the instant blood-mediated inflammatory response [IBMIR], ability to biopsy). The aim of this study was to determine whether endoscopic biopsy of islet allografts transplanted into the GSMS in diabetic pigs can provide histopathological and...

The immunologic barriers to successful xenotransplantation are related to the presence of natural anti-pig antibodies in humans and non-human primates that bind to antigens expressed on the transplanted pig organ (the most important of which is galactose-α1,3-galactose [Gal]), and activate the complement cascade, which results in rapid destruction...

In pig-to-baboon heart/artery patch transplantation models, adequate costimulation blockade prevents a T-cell response. After heart transplantation, coagulation dysfunction (thrombocytopenia, reduced fibrinogen, increased D-dimer) and inflammation (increased C-reactive protein [CRP]) develop. We evaluated whether coagulation dysfunction and/or infl...

Pig islet grafts have been successful in treating diabetes in animal models. One remaining question is whether neonatal pig isletlike cell clusters (NICC) are resistant to the early loss of islets from the instant blood-mediated inflammatory reaction (IBMIR). Neonatal isletlike cell clusters were harvested from three groups of piglets-(i) wild-type...

The longest survival of a non-human primate with a life-supporting kidney graft to date has been 90 days, although graft survival > 30 days has been unusual. A baboon received a kidney graft from an α-1,3-galactosyltransferase gene-knockout pig transgenic for two human complement-regulatory proteins and three human coagulation-regulatory proteins (...

Immunosuppressed patients and experimental nonhuman primates are at risk of opportunistic infection. We report a Myroides spp infection in an immunosuppressed baboon that had received a life-supporting kidney from a genetically-engineered pig. The baboon received a costimulation blockade-based immunosuppressive regimen as well as two anti-inflammat...

Background Three costimulation blockade-based regimens have been explored after transplantation of hearts from pigs of varying genetic backgrounds to determine whether CTLA4-Ig (abatacept) or anti-CD40mAb+CTLA4-Ig (belatacept) can successfully replace anti-CD154mAb.Methods All pigs were on an α1,3-galactosyltransferase gene-knockout/CD46 transgenic...

In the pig-to-nonimmunosuppressed baboon artery patch model, a graft from an α1,3-galactosyltransferase gene-knockout pig transgenic for human CD46 (GTKO/CD46) induces a significant adaptive immune response (elicited anti-pig antibody response, increase in T cell proliferation on MLR, cellular infiltration of the graft), which is effectively preven...

Chronic pancreatitis (CP) is long-standing inflammation of the pancreas, which can present as episodes of acute inflammation in a previously injured pancreas or as chronic damage with persistent pain and/or malabsorption. Recurrent pancreatitis events often leads to CP, which in turn may result in malabsorption from exocrine deficiency; diabetes fr...

Background Xenotransplantation of porcine islets can reverse diabetes in non-human primates. The remaining hurdles for clinical application include safe and effective T-cell-directed immunosuppression, but protection against the innate immune system and coagulation dysfunction may be more difficult to achieve. Islet-targeted genetic manipulation of...

Diabetes mellitus is increasing worldwide. Type 1 diabetes can be treated successfully by islet allotransplantation, the results of which are steadily improving. However, the number of islets that can be obtained from deceased human donors will never be sufficient to cure more than a very small percentage of patients who might benefit from transpla...

The generation of pigs with genetic modifications has significantly advanced the field of xenotransplantation. New genetically engineered pigs were produced on an α1,3-galactosyltransferase gene-knockout background with ubiquitous expression of human CD46, with islet beta cell-specific expression of human tissue factor pathway inhibitor and/or huma...

Background The need for pig islet xenotransplantation in patients with type 1 diabetes is compelling; however, the ideal age at which islets should be isolated from the donor pig remains uncertain. Pig islet transplantation in primates, as a valuable pre-clinical model, has been explored using adult, neonatal, fetal pig islets, and also pancreatic...

Background: Total pancreatectomy (TP) is a morbid but sometimes necessary operation. Robotic TP is not often reported but may harbor some advantages compared to the open approach. This manuscript details a single institution's outcomes and technique of robotic TP. An accompanying video demonstrates a robotic TP with auto islet cell transplantation...

Introduction: The management of incidentally discovered renal stones in living donor candidates is evolving. Recently, the safety and efficacy of ex vivo ureteroscopy for stone removal in donor kidneys have been described.1–3 Here, we present our experience with ex vivo ureteroscopy and laser infundibulotomy for the treatment of a stone contained w...

Streptozotocin (STZ) is used to induce diabetes in experimental animals. It has a variety of adverse effects, ranging from nausea, emesis, and weight loss to liver damage, renal failure, and metabolic acidosis. STZ also has effects on the immune system, being associated with lymphopenia in rodents, the mechanism of which is not fully understood. We...

Hereditary pancreatitis is an autosomal dominant disorder with 80% penetrance and variable expressivity. The vast majority of cases have been linked to mutations within the cationic trypsinogen gene, also referred to as serine protease 1 (PRSS1). Other than inheritance, PRSS1 pancreatitis has been considered clinically and pathologically indistingu...

Pigs have emerged as potential sources of islets for clinical transplantation. Wild-type porcine islets (adult and neonatal) transplanted into the portal vein have successfully reversed diabetes in nonhuman primates. However, there is a rapid loss of the transplanted islets on exposure to blood, known as the instant blood-mediated inflammatory reac...

We examined the influence of regulatory dendritic cells (DCreg), generated from cytokine-mobilized donor blood monocytes in vitamin D3 and IL-10, on renal allograft survival in a clinically relevant rhesus macaque model. DCreg expressed low MHC class II and costimulatory molecules, but comparatively high levels of programmed death ligand-1 (B7-H1),...

Platelet aggregation plays a key role in dysregulation of coagulation and development of TM in pig cardiac xenografts transplanted into baboon recipients. The present study aimed to evaluate the influence of pig genetic modification on human platelet aggregation induced by pig endothelial cells (EC).Methods and MaterialsUsing a Chrono-log Whole Blo...

Type 1 diabetes (T1D) is a major health problem throughout the world. In the U.S., it is estimated that about 1.5 million people suffer from T1D. Even when well controlled—by frequent monitoring of blood glucose and administration of insulin, the long-term complications of the disease are significant and include cardiovascular disease, nephropathy,...

Background: Large animals treated with immunosuppressive drugs for preclinical experiments of transplantation have increased risks of infection, which can be compounded by the induction of diabetes if islet transplantation is planned. Methods: We report our experience with severe sepsis in two young cynomolgus monkeys and five pigs that were sub...

Background: Islets obtained from genetically‐engineered (GE) pigs with Gal‐knockout (GTKO) and high expression of hCD46 have shown long‐term function and successful correction of insulin independence in nonhuman primates (NHP). Two anti‐coagulant genes (hTFPI and hCD39), and an immunosuppressive gene (pCTLA4Ig) have been added to the GTKO/hCD46 bac...

Clinical outcome in BK virus nephropathy (BKVN) was examined in relation to clinical and histologic parameters with reference to the Banff Working Proposal 2009, which emphasizes tubular injury and viral load. Seventy one patients were evaluated in three eras: (i) Era-I: No BKV PCR performed (n = 36), (ii) Era-II: PCR performed for rising creatinin...

The shortage of organs and cells from deceased individuals continues to restrict allotransplantation. Pigs could provide an alternative source of tissue and cells but the immunological challenges and other barriers associated with xenotransplantation need to be overcome. Transplantation of organs from genetically modified pigs into non-human primat...

Chronic pancreatitis is an inflammatory disease of the pancreas that causes permanent changes in the function and structure of the pancreas. It is most commonly a complication of cystic fibrosis or due to a genetic predisposition. Chronic pancreatitis generally presents symptomatically as recurrent abdominal pain, which becomes persistent over time...

As with other similar-sized programs across the country, kidney transplantation has evolved at the University of Pittsburgh. The shortage of organs represents the biggest problem, and in response there has been an increase in the number of live-donor and extended-criteria-donor transplants. Laparoscopic nephrectomy techniques have been widely used...

Sarcoidosis is a systemic granulomatous disease of unknown etiology affecting patients from all genetic backgrounds. Pancreatic involvement is rare; the first case was described on autopsy in 1937. We present a case of pancreatic sarcoidosis without a history of the disease presenting as biliary obstruction mimicking pancreatic malignancy. We also...

Risk factors associated with surgical site infection (SSI) and the development of short-term complications in macaques undergoing vascular access port (VAP) placement are evaluated in this study. Records from 80 macaques with VAPs were retrospectively reviewed. Logistic regression was used to identify factors associated with short-term post-operati...

Cell-based diabetes therapy requires an abundant cell source. Here, we report reversal of diabetes for more than 100 d in cynomolgus macaques after intraportal transplantation of cultured islets from genetically unmodified pigs without Gal-specific antibody manipulation. Immunotherapy with CD25-specific and CD154-specific monoclonal antibodies, FTY...

We have previously shown that pig-to-primate intraportal islet xenografts reverse diabetes, escape hyperacute rejection, and undergo acute cellular rejection in non-immunosuppressed recipients. To gain a better understanding of mechanisms contributing to xenoislet rejection in non-human primates we examined gene expression in livers bearing islet x...

Streptozotocin (STZ) is widely applied in animal models of insulin-dependent diabetes mellitus. Adverse effects of STZ mainly concern liver and kidney. In nonhuman primates a single 100-150 mg/kg dose invariably induces diabetes with only rare adverse effects. We report one animal with renal failure necessitating sacrifice. Body weight (age) might...

The functional response and immunobiology of primarily non-vascularized islet cell xenografts remain poorly defined in non-human primates. We transplanted 20,000 adult porcine islet equivalents/kg (purified and cultured for 48-h) intraportally into six streptozotocin-diabetic and two non-diabetic rhesus macaques. Two recipients were killed at vario...

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In a preclinical, nonhuman primate islet allotransplant model, the authors evaluated a novel immunosuppressive combination of basiliximab for induction and of RAD and FTY720 for maintenance. Five ABO-compatible and mixed lymphocyte reactivity-mismatched streptozotocin-induced diabetic juvenile cynomolgus monkeys underwent transplantation intraporta...

Type 1 diabetes continues to represent a therapeutic challenge and consequently remains a substantial burden for patients and their families. Secondary diabetes complications, observed in 30% to 50% of patients affected by type 1 diabetes, result in poor quality of life, premature death, and considerable healthcare costs.1 The principal determinant...