Clinical significance of bacterial cultures from 28 autologous islet cell transplant solutions

Total pancreatectomy with intraportal islet autotransplantation for pancreatic malignancies: a literature overview

INTRODUCTION

'Brittle Diabetes' (BD) is a life-threatening metabolic complication after total pancreatectomy (TP). More than 500 Intraportal islet autotransplantation (IAT) have been performed to prevent this complication, with almost 70% insulin independence after 3 years. Even when insulin independence was not achieved, IAT successfully prevented severe hypoglycemia. Currently, preliminary results for oncologic situations are promising, but their oncological outcomes are still a matter of debate.

AREAS COVERED

We performed a bibliographic research of the last 25 years of data. Articles published in English in peer-reviewed journals were retained. In France, auto- and allo-islet transplantation was recently recognized as a valuable treatment for BD by the national health authority. While accepted for benign diseases, the risk of tumor spreading after IAT in oncologic situations is a source of concern.

EXPERT OPINION

Preliminary results of IAT in oncological situations are very encouraging. So far, there is no evidence of tumor dissemination. In our opinion, to overcome BD TP with IAT for resectable pancreatic malignancies in patients with a higher risk of postoperative pancreatic fistula and extended pancreatic cancers can be safely performed. Diagnosis of malignancy should not be considered as an exclusion criterion for IAT.

Clinical Significance of Postoperative Antibiotic Treatment for Positive Islet Cultures After Total Pancreatectomy With Islet Autotransplantation

OBJECTIVES

Islet cultures are routinely performed in total pancreatectomy with islet autotransplantation (TPIAT), and the need for empiric antibiotic treatment based on culture results is unknown. We evaluated the effect of postoperative antibiotic treatment for positive islet cultures on clinical infection.

METHODS

Seventy-nine patients undergoing TPIAT were reviewed. Prophylactic perioperative ceftriaxone and metronidazole were administered, and transplanted islet preparations included ciprofloxacin. Postoperative antibiotics were not routinely given for positive cultures unless a clinical infection was suspected. The primary end point was 30-day infectious complications.

RESULTS

Fifty-one patients (65%) had a positive culture. Overall, 39 patients (87%) had organisms susceptible to our perioperative antibiotic regimen. There was no difference in the infectious complication rate between those with positive compared with negative cultures (16% vs 29%, P = 0.17). Patients with a positive culture had similar 30-day postoperative infectious complication rates whether receiving postoperative antibiotics (n = 7) or not (14% vs 16%, P = 0.91). Only 1 patient had a correlation of clinical and islet cultures.

CONCLUSIONS

Beyond prophylactic antibiotics, empiric antibiotic treatment for a positive culture is not warranted and provides a rationale for the abandonment of routine cultures in TPIAT.

Total Pancreatectomy with Autologous Islet Cell Transplantation-The Current Indications

Total pancreatectomy is a major complex surgical procedure involving removal of the whole pancreatic parenchyma and duodenum. It leads to lifelong pancreatic exocrine and endocrine insufficiency. The control of surgery-induced diabetes (type 3) requires insulin therapy. Total pancreatectomy with autologous islet transplantation (TPAIT) is performed in order to prevent postoperative diabetes and its serious complications. It is very important whether it is safe and beneficial for patients in terms of postoperative morbidity and mortality, and long-term results including quality of life. Small duct painful chronic pancreatitis (CP) is a primary indication for TPAIT, but currently the indications for this procedure have been extended. They also include hereditary/genetic pancreatitis (HGP), as well as less frequent indications such as benign/borderline pancreatic tumors (intraductal papillary neoplasms, neuroendocrine neoplasms) and “high-risk pancreatic stump”. The use of TPAIT in malignant pancreatic and peripancreatic neoplasms has been reported in the worldwide literature but currently is not a standard but rather a controversial management in these patients. In this review, history, technique, indications, and contraindications, as well as short-term and long-term results of TPAIT, including pediatric patients, are described.

Sterility Cultures Following Pancreatectomy with Islet Autotransplantation in the Pediatric Population: Do They Matter?

BACKGROUND

Pancreatectomy with islet autotransplantation (IAT) is a treatment option for children with debilitating chronic pancreatitis. Sterility cultures from preservation solutions are often positive, yet their impact has not been well studied in children.

METHODS

A retrospective review of all patients who underwent IAT from 2015 to 2018 at a single institution was performed. Sterility culture data were obtained from both the pancreas transport and islet transplant media. All patients received prophylactic perioperative meropenem and vancomycin for 72 h per our protocol. If cultures resulted positive, antibiotics were extended for a total of 7 days. Primary outcomes were postoperative fever and 30-day infectious complications.

RESULTS

Forty-one patients underwent IAT during the study period. Seventeen (41.5 %) patients had negative cultures of both the transport and transplant media, while 24 (58.5 %) patients had a positive culture from either sample. Of these patients, 13 (31.7 %) were positive in both, 10 (24.4 %) were positive in only the transport media, and 1 (2.4 %) was positive in only the transplant media. Patients with positive transplant media were similar with regard to age, gender, etiology, and disease duration compared to those with negative transplant media (all p > 0.05), but the positive group was more likely to have a pancreatic stent in place at the time of surgery (38.5 % vs. 4.2 %, p = 0.01). The overall postoperative infectious complication rate was 31.2 % (n = 13). No difference was detected between the transplant positive and negative culture groups in postoperative fever or 30-day infectious complications (p > 0.05 for each).

CONCLUSION

An existing pancreatic stent at the time of pancreatectomy with IAT is a risk factor for positive sterility cultures. However, positive islet transplant media culture was not associated with increased risk of post-IAT infection or morbidity in the setting of an empiric antibiotic protocol. Future work is necessary to study the optimal perioperative antibiotic regimen in pediatric IAT.

Impact of microbial contamination of the islet product during total pancreatectomy with islet autotransplantation

BACKGROUND

The combined use of interleukin-1β and tumor necrosis factor-α blockers in the peritransplant period has improved outcomes of total pancreatectomy with islet autotransplantation (TPIAT). However, these drugs may suppress the immune system, resulting in severe infection.

METHODS

We retrospectively investigated the impact of microbial-contaminated islet product on posttransplant complications and metabolic outcomes of TPIAT patients receiving the IL-1β and TNF-blockade treatment at our center.

RESULTS

Among 108 TPIAT patients, 37 patients (34%) received contaminated products. Preoperative stent treatment and fibrosis score were independent risk factors for the contamination. There were no significant differences between the contaminated and noncontaminated product groups in posttransplant infectious complication rate, length of hospitalization, or readmission rate. However, islet equivalents (P < .0001) and insulin independence rate (P = .036) at 6 months were significantly lower for patients receiving contaminated product.

CONCLUSIONS

These results suggest that combined anti-inflammatory drug use is safe and well tolerated in TPIAT patients who receive contaminated islet product and does not increase the rate of infectious complications; however, contaminated islet product is associated with poor metabolic outcomes.

Early Infectious Complications After Total Pancreatectomy with Islet Autotransplantation: a Single Center Experience

INTRODUCTION

We assessed whether positive microbiological cultures from the islet preparation had any effect on the risk of infectious complications (IC) after total pancreatectomy with islet autotransplantation (TPIAT) in our center.

METHODS

We analyzed preservation fluid and final islet product surveillance cultures with reference to clinical data of patients undergoing TPIAT. All patients received routine prophylactic broad-spectrum antibiotics.

RESULTS

The study involved 10 men and 18 women with a median age of 39 years. Over 30% of surveillance cultures during pancreas processing grew bacterial strains with predominantly polymicrobial contaminations (13 of 22 (59%)). At least one positive culture was identified in almost half of the patients (46%) undergoing TPIAT and a third had both surveillance cultures positive. Infectious complications affected 50% of patients. After excluding cases of PICC line-associated bacteremia/fungemia present on admission, incidence of IC was higher in cases of positive final islet product culture than in those with negative result (57% vs. 21%), which also corresponded with the duration of chronic pancreatitis (p = 0.04). Surgical site infections were the most common IC, followed by fever of unknown origin. There was no concordance between pathogens isolated from the pancreas and those identified during the infection.

CONCLUSIONS

While IC was common among TPIAT patients, we found no concordance between pathogens isolated from the pancreas and those identified during infection. Contamination of the final islet product was of clinical importance and could represent a surrogate marker for higher susceptibility to infection.

Microbial Contamination, Infection, and Antimicrobial Use During Total Pancreatectomy With Islet Autotransplantation

OBJECTIVES

Total pancreatectomy with islet autotransplantation can relieve pain associated with chronic pancreatitis while preserving islet function. Islet preparations are often contaminated by enteric flora. We assessed the impact of contaminated islet preparations on the prevalence of postoperative infection.

METHODS

Electronic health records for patients who underwent total pancreatectomy with islet autotransplantation from August 1, 2011, to November 15, 2017 were retrospectively reviewed to compare the prevalence of postoperative infection in patients with a positive islet culture and islet culture negative patients.

RESULTS

Sixty-one patients were included. Twenty-nine patients (47.5%) had a positive islet culture, and 23 (79.3%) of these patients received antimicrobial prophylaxis. The prevalence of postoperative infection did not differ between the islet culture positive and islet culture negative groups (41% vs 34%, P = 0.57). No infections occurred in the 6 islet culture positive patients who did not receive prophylaxis. No difference in intensive care unit or hospital length of stay or in 30-day or 90-day readmission rates were observed.

CONCLUSIONS

Despite the common use of postoperative systemic antimicrobials, we observed no difference in the prevalence of postoperative infection, length of stay, or hospital readmission in patients receiving a contaminated islet preparation. If prophylactic antimicrobials are used, the duration should be minimized.

Pancreatic Islet Transplantation in Humans: Recent Progress and Future Directions

Pancreatic islet transplantation has become an established approach to β-cell replacement therapy for the treatment of insulin-deficient diabetes. Recent progress in techniques for islet isolation, islet culture, and peritransplant management of the islet transplant recipient has resulted in substantial improvements in metabolic and safety outcomes for patients. For patients requiring total or subtotal pancreatectomy for benign disease of the pancreas, isolation of islets from the diseased pancreas with intrahepatic transplantation of autologous islets can prevent or ameliorate postsurgical diabetes, and for patients previously experiencing painful recurrent acute or chronic pancreatitis, quality of life is substantially improved. For patients with type 1 diabetes or insulin-deficient forms of pancreatogenic (type 3c) diabetes, isolation of islets from a deceased donor pancreas with intrahepatic transplantation of allogeneic islets can ameliorate problematic hypoglycemia, stabilize glycemic lability, and maintain on-target glycemic control, consequently with improved quality of life, and often without the requirement for insulin therapy. Because the metabolic benefits are dependent on the numbers of islets transplanted that survive engraftment, recipients of autoislets are limited to receive the number of islets isolated from their own pancreas, whereas recipients of alloislets may receive islets isolated from more than one donor pancreas. The development of alternative sources of islet cells for transplantation, whether from autologous, allogeneic, or xenogeneic tissues, is an active area of investigation that promises to expand access and indications for islet transplantation in the future treatment of diabetes.

Microbial contamination of transplant solutions during pancreatic islet autotransplants is not associated with clinical infection in a pediatric population

BACKGROUND/OBJECTIVES

Total pancreatectomy and islet autotransplant (TP-IAT) is a potential treatment for children with severe refractory chronic pancreatitis. Cultures from the resected pancreas and final islet preparation are frequently positive for microbes. It is unknown whether positive cultures are associated with adverse outcomes in pediatric patients.

METHODS

We reviewed the medical records of children (n = 86) who underwent TP-IAT from May 2006-March 2015 with emphasis on demographics, previous pancreatic interventions, culture results, islet yield, hospital days, posttransplant islet function, and posttransplant infections. We compared outcomes in patients with positive (n = 57) and negative (n = 29) cultures.

RESULTS

Patients with positive cultures had higher rates of previous pancreas surgery (P = 0.007) and endoscopic retrograde cholangiopancreatography (P < 0.0001). Positive cultures were not associated with posttransplant infections (P = 1.00) or prolonged hospital length of stay (P = 0.29). Patients with positive final islet preparation culture showed increased rates of graft failure at 2 years posttransplant (P = 0.041), but not when adjusted for islet mass transplanted (P = 0.39).

CONCLUSIONS

Positive cultures during pediatric TP-IATs do not increase the risk of posttransplant infections or prolong hospital length of stay. Endocrine function depends on islet mass transplanted.

Infectious complications of pancreatic islet transplantation: clinical experience and unanswered questions

Pancreatic islet transplantation is an evolving treatment modality for type I diabetes mellitus. While the field has advanced significantly over the course of the past three decades, our understanding of the infectious complications of pancreatic islet transplantation remains quite limited. This review aims to describe the current literature relating to infectious complications of pancreatic islet transplantation, including the role of microbiologically contaminated islet preparations in disease pathogenesis, our current understanding of the epidemiology and outcomes of cytomegalovirus and other infectious complications of pancreatic islet transplantation, and infectious concerns related to the use of porcine pancreatic islet cell xenografts. This review also highlights unanswered clinical questions and suggests areas of future research to mitigate infectious complications in recipients of islet transplantation.

Positive sterility cultures of transplant solutions during pancreatic islet autotransplantation are associated infrequently with clinical infection

BACKGROUND

Chronic pancreatitis is a painful and often debilitating disease. Total pancreatectomy with intra-portal islet autotransplantation (TP-IAT) is a treatment option that allows for pain relief and preservation of beta-cell mass, thereby minimizing the complication of diabetes mellitus. Cultures of harvested islets are often positive for bacteria, possibly due to frequent procedures prior to TP-IAT, such as endoscopic retrograde cholangiopancreatography (ERCP), stenting, or other operative drainage procedures. It is unclear if these positive cultures contribute to post-operative infections.

HYPOTHESIS

We hypothesized that positive cultures of transplant solutions will not be associated with increased infection risk.

METHODS

We reviewed retrospectively the sterility cultures from both the pancreas preservation solution used to transport the pancreas and the final islet preparation for intra-portal infusion of patients who underwent TP-IAT between April 2006 and November 2012. Two hundred fifty-one patients underwent total, near-total, or completion pancreatectomy with IAT and had complete sterility cultures. All patients received prophylactic peri-operative antibiotics. Patients with positive pancreas preservation solution or islet sterility cultures received further antibiotics for 5-7 d. Patients' medical records were reviewed for post-operative infections and causative organisms.

RESULTS

Of the 251 patients included, 151 (61%) had one or more positive bacterial cultures from the pancreas preservation solution or final islet product. Seventy-three of the 251 patients (29%) had an infectious complication. Thirty-four of the 73 (22%) patients with a post-operative infectious complication also had positive cultures. Only seven of 151 patients with positive cultures (4.7%) had an infectious complication caused by the same organism as that isolated from their pancreas or islet cell preparation.

CONCLUSIONS

In autologous islet preparations, isolation solutions frequently have positive cultures, but this finding is associated infrequently with clinical infection.

Autotransplantation of culture-positive islet product: is dirty always bad?

BACKGROUND

In selected patients, total pancreatectomy with islet autotransplantation (TPIAT) effectively relieves pain caused by chronic pancreatitis and ameliorates the brittle diabetes of the apancreatic state. Patients often undergo multiple endoscopic and surgical interventions prior to TPIAT, increasing the risk for pancreas colonization with enteric microorganisms. Little is known of the safety of transplanting islet cells with microbial contamination.

METHODS

A prospectively collected database of 80 patients submitted to TPIAT at the Medical University of South Carolina from March 2009 to February 2012 was retrospectively reviewed. Patient charts were reviewed for postoperative infectious complications and organisms identified were compared with those identified in pre-transplant islet cultures.

RESULTS

A total of 35 patients (43.8%) had a positive pre-transplant islet cell Gram stain or islet cell culture from the final islet preparation solution. Of these 35 patients, 33 (94.3%) were given antibiotics prophylactically post-transplant for a positive islet Gram stain or culture. Twenty patients (57.1%) receiving Gram stain- or culture-positive islets developed postoperative infectious complications, but only four patients (11.4%) developed infections that concorded with their pre-transplant islet product.

CONCLUSIONS

Islet transplant solutions are frequently culture-positive, presumably as a result of prior pancreas intervention. Microbial contamination of islet preparations should not preclude autotransplantation.

Prior surgery determines islet yield and insulin requirement in patients with chronic pancreatitis

BACKGROUND

Total pancreatectomy with islet autotransplantation (TP-IAT) is safe and effective in the management of intractable pain associated with chronic pancreatitis (CP). Prevention of pancreatogenic diabetes after TP-IAT is related to islet yield from the diseased pancreas. The purpose of this study is to compare islet yield and insulin requirement in the 76 patients who underwent different surgical procedures before TP-IAT at the Medical University of South Carolina between 2009 and 2011.

METHODS

Patients were grouped into four categories based on the operation they had before TP-IAT: transduodenal sphincteroplasty/no prior surgery (n=50), Whipple or Beger procedure (n=14), distal pancreatectomy (n=8), or lateral pancreaticojejunostomy (n=4). Islets were harvested from pancreases of those patients at our current good manufacturing practice facility. Total unpurified islets were transplanted into patients via portal vein infusion. Pancreatic fibrosis, islet yield, cell viability, and insulin requirement were measured.

RESULTS

The pancreases of transduodenal sphincteroplasty/no prior surgery and Whipple or Beger procedure patients were less fibrotic and had higher islet yield compared with those who had distal pancreatectomy or lateral pancreaticojejunostomy. Higher islet yield also correlated with a greater diabetes-free rate and a lesser insulin requirement at the following intervals: preoperative, postoperative, and 6 months after TP-IAT.

CONCLUSIONS

Prior surgery is strongly correlated with the extent of pancreatic fibrosis, islet yield, and insulin requirements in CP patients undergoing TP-IAT. The history of prior pancreatic resection and drainage procedures may be used to predict postoperative islet function and help to determine the optimal timing for TP-IAT in CP patients.

A Review of Autologous Islet Transplantation

Autologous islet transplantation after total or semitotal pancreatectomy aims to preserve insulin secretory function and prevent the onset of diabetes. The major indication for pancreatectomy is chronic pancreatitis with severe abdominal pain, a benign pancreatic tumor, and trauma. The metabolic outcome of autologous islet transplantation is better than that of allogeneic transplantation and depends on the number of transplanted islets. Achieving islet isolation from a fibrous or damaged pancreas is one of the biggest challenges of autologous islet transplantation; a major complication is portal vein thrombosis after crude islet infusion. However, the incidence of portal vein thrombosis has decreased as islet preparation techniques have improved over time.

Isolation of human islets for autologous islet transplantation in children and adolescents with chronic pancreatitis

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. The pain eventually becomes disabling. Once specific medical treatments and endoscopic interventions are no longer efficacious, total pancreatectomy is the alternative of choice for helping the patient achieve pain control. While daily administrations of digestive enzymes cannot be avoided, insulin-dependent diabetes can be prevented by transplanting the isolated pancreatic islets back to the patient. The greater the number of islets infused, the greater the chance to prevent or at least control the effects of surgical diabetes. We present here a technical approach for the isolation and preservation of the islets proven to be efficient to obtain high numbers of islets, favoring the successful treatment of young patients.

Autologous islet cell transplantation to prevent surgical diabetes

Autologous islet transplantation (AIT) is performed to prevent surgical diabetes after total or semi-total pancreatectomy for the treatment of chronic pancreatitis with severe abdominal pain. In addition, AIT is used in cases of benign pancreatic tumors and pancreatic trauma. It has been shown that AIT results in better outcomes in terms of glycemic control compared with allogeneic islet transplantation. The reasons for the favorable outcomes of AIT are thought to be: (i) patients have no autoimmune diseases; (ii) the transplanted islets do not suffer allogeneic rejection; (iii) diabetogenic antirejection drugs are not required; (iv) pancreata do not undergo a cytokine storm as a result of periods of brain death; (v) the period of cold preservation of retrieved pancreata is short; (vi) the isolated islets are immediately transplanted without culture; and (vii) pancreata with pancreatitis may contain more progenitor cells. Further research into AIT would help improve the results of allogeneic islet transplantation. Conversely, the technical difficulties associated with islet isolation appear to be the largest hurdle for AIT; therefore, remote center islet isolation may prove to be key in the promotion of this treatment.

Experience of Microbiological Screening of Human Hepatocytes for Clinical Transplantation

Hepatocyte transplantation is being used in patients with liver-based metabolic disorders and acute liver failure. Hepatocytes are isolated from unused donor liver tissue under GMP conditions. Cells must be free of microbiological contamination to be safe for human use. The experience of microbiological screening during 72 hepatocyte isolation procedures at one center is reported. Samples were taken at different stages of the process and tested using a blood culture bottle system and Gram stain. Bacterial contamination was detected in 37.5% of the UW organ preservative solutions used to transport the liver tissue to the Cell Isolation Unit. After tissue processing the contamination was reduced to 7% overall in the final hepatocyte product, irrespective of the presence of initial contamination of the transport solution. The most common organisms recovered were coagulase-negative staphylococci, a skin commensal. A total of 41 preparations of fresh or cryopreserved hepatocytes were used for cell transplantation in children with liver-based metabolic disorders without any evidence of sepsis due to infusion of hepatocytes. In conclusion, the incidence of bacterial contamination of the final product was low, confirming the suitability of the organs used, hepatocyte isolation procedure, and the environmental conditions of the clean room.