Selecting suitable solid organ transplant donors: Reducing the risk of donor-transmitted infections

Donor heart selection: Evidence-based guidelines for providers

The proposed donor heart selection guidelines provide evidence-based and expert-consensus recommendations for the selection of donor hearts following brain death. These recommendations were compiled by an international panel of experts based on an extensive literature review.

The Association of Organ Preservation Fluid Pathogens with Early Infection-Related Events after Kidney Transplantation

(1) Background: The need to elucidate the microbial patterns in preservation fluid and explore their relationship with early infection-related events post kidney transplant and investigate antimicrobial resistance and the effects of preemptive antibiotic therapy. (2) Methods: This retrospective study analyzed the clinical data of 514 kidney transplant donors and 808 recipients from April 2015 to October 2020. Clinical data of donor and recipient characteristics, preservation fluid microbes, early infections (≤30 days), probable donor-derived infections (P-DDIs), antimicrobial resistance and preemptive antibiotic therapy was collected. (3) Results: The incidence of bloodstream (10.3% versus 5.2%, p = 0.006) and graft-site infections (9.7% versus 4.6%, p = 0.004) was significantly higher in recipients with culture-positive preservation fluid. In addition, recipients with ESKAPE pathogens or Candida species had a notably higher rate of bloodstream infections (14.1% versus 6.9%, p = 0.033) and graft-site infections (16.7% versus 3.5%, p < 0.01) than those with other positive pathogens. Preemptive antibiotic therapy decreased the bloodstream infection rate (11.8% versus 35.7%, p = 0.047) when preservation fluid was positive for ESKAPE pathogens. (4) Conclusions: Culture-positive preservation fluid has potential implications for kidney transplant recipients. ESKAPE pathogens or Candida species in preservation fluid as well as their antimicrobial resistance properties and non-preemptive antibiotic therapy could pose a risk of early infection-related events.

Infective endocarditis in solid organ transplant: a review

PURPOSE OF REVIEW

Infective endocarditis remains an uncommon disease with significant morbidity and mortality. In the last two decades, progress has been made describing the unique aspects of infective endocarditis in solid organ transplant (SOT) recipients.

RECENT FINDINGS

Incidence of infective endocarditis in SOT is higher when compared with the general population. End-stage organ dysfunction, diabetes mellitus, older age, and prior intravenous lines have been identified as risk factors predisposing to infective endocarditis in SOT. Staphylococci and enterococci represent the most frequently isolated pathogens, whereas fungi are rarely isolated. Median time from transplantation to diagnosis ranges from 33 to 66 months. Nosocomial acquisition and mural endocarditis are more common in SOT recipients with infective endocarditis. Procurement of organs from patients with infective endocarditis might be well tolerated so long as close monitoring and targeted antibiotics are given. Selected patients might benefit from heart transplantation as definitive or salvage therapy for infective endocarditis. Outcomes of infective endocarditis in SOT recipients compared with the general population might be similar; however, patient survival and graft function are reduced when recipients suffer from infective endocarditis.

SUMMARY

Infective endocarditis although rare can affect donors and recipients involved in the SOT process. Recognition of the unique characteristics in the presentation, prevention, medical, and surgical therapy of this disease is essential in order to minimize adverse outcomes.

Candida Contamination in Kidney and Liver Organ Preservation Solution: Does It Matter?

INTRODUCTION

Fungal infections remain a major challenge affecting outcomes after kidney (KT) and liver transplantation (LT).

METHODS

In this retrospective single center study, the incidence of Candida contamination in renal and hepatic graft preservation solution (PS) was evaluated. In addition, Candida associated infections in recipients and related complications were analyzed.

RESULTS

Overall, the PS of 1248 hepatic and 1273 renal grafts were evaluated. The incidence of fungal contamination in the PS of hepatic and renal grafts was 1.2% and 0.86%, respectively. Additionally, the hepatic PS of one patient who underwent a combined liver-kidney transplant had Candida contamination. Candida albicans was the most common organism (70.4%) and 65.4% of the patients received antifungal treatment. Candida-associated complications in the recipients was 19%. Complications in LT patients included Candida peritonitis and Candida sepsis. Two KT recipients with contaminated PS developed a mycotic aneurysm at the anastomotic site resulting in severe bleeding. The 1-year mortality in patients with PS contamination for LT and KT recipients was 33% and 18%, respectively. Although the incidence of fungal contamination of PS was low, contaminated PS was associated with a high mortality.

CONCLUSION

The results of the study suggest that PS should be evaluated for fungal growth.

2020 European guideline on the management of syphilis

The 2020 edition of the European guideline on the management of syphilis is an update of the 2014 edition. Main modifications and updates include: -The ongoing epidemics of early syphilis in Europe, particularly in men who have sex with men (MSM) -The development of dual treponemal and non-treponemal point-of-care (POC) tests -The progress in non-treponemal test (NTT) automatization -The regular episodic shortage of benzathine penicillin G (BPG) in some European countries -The exclusion of azithromycin as an alternative treatment at any stage of syphilis -The pre-exposure or immediate post-exposure prophylaxis with doxycycline in populations at high risk of acquiring syphilis.

Diverse Routes of Allograft Tolerance Disruption by Memory T Cells

Memory T lymphocytes constitute a significant problem in tissue and organ transplantation due their contribution to early rejection and their relative resistance to tolerance-promoting therapies. Memory cells generated by environmental antigen exposure, as with T cells in general, harbor a high frequency of T cell receptors (TCR) spontaneously cross-reacting with allogeneic major histocompatibility complex (MHC) molecules. This phenomenon, known as ‘heterologous’ immunity, is thought to be a key barrier to transplant tolerance induction since such memory cells can potentially react directly with essentially any prospective allograft. In this review, we describe two additional concepts that expand this commonly held view of how memory cells contribute to transplant immunity and tolerance disruption. Firstly, autoimmunity is an additional response that can comprise an endogenously generated form of heterologous alloimmunity. However, unlike heterologous immunity generated as a byproduct of indiscriminate antigen sensitization, autoimmunity can generate T cells that have the unusual potential to interact with the graft either through the recognition of graft-bearing autoantigens or by their cross-reactive (heterologous) alloimmune specificity to MHC molecules. Moreover, we describe an additional pathway, independent of significant heterologous immunity, whereby immune memory to vaccine- or pathogen-induced antigens also may impair tolerance induction. This latter form of immune recognition indirectly disrupts tolerance by the licensing of naïve alloreactive T cells by vaccine/pathogen directed memory cells recognizing the same antigen-presenting cell in vivo. Thus, there appear to be recognition pathways beyond typical heterologous immunity through which memory T cells can directly or indirectly impact allograft immunity and tolerance.

Antibiotic therapy in case of positive cultures of kidney transplant preservation fluid: a nationwide survey of prescribing practices

Our survey aimed to describe current prescribing practices for perioperative antibiotic prophylaxis in French kidney transplant centers. We conducted a nationwide cross-sectional clinical vignette-based survey that we sent via email to hospital practitioners involved in perioperative management of kidney transplant patients (KTR). Nearly half of practitioners contacted (182/427, 42.6%) were respondents. A total of 167 getting enough kidney transplant activity were eligible for the survey. The response rate was 50.7% (68/134) among interns and 33.8% (99/293) among seniors. Positive perfusion fluids (PF) cultures for methicillin-susceptible Staphylococcus aureus were associated with antibiotic prescribing in 35% of cases, with no difference in prescribing in patients with diabetes, obesity, or delayed graft function. Antibiotic prescribing was most frequent with Pseudomonas aeruginosa (67%) and Klebsiella pneumoniae strains producing extended spectrum β-lactamases (57%). About 77%, 16%, and 13% of respondents, respectively, reported the existence of local practice guidelines for surgical antibiotic prophylaxis, a standardized approach for antibiotic prescribing in case of positive kidney transplant PF cultures, and local practice guidelines for systematical antibiotic prophylaxis in the early post-transplant period. In France, antibiotic prophylaxis practices in the perioperative kidney transplant period are very heterogeneous. To prevent unnecessary prescribing and bacterial resistance, evidence-based practice guidelines should be developed.

Microbiological epidemiology of preservation fluids in transplanted kidney: a nationwide retrospective observational study

OBJECTIVES

Kidney transplant recipients are at high-risk for donor-derived infections in the early post-transplant period. Transplant preservation fluid (PF) samples are collected for microbiological analysis. In case of positive PF cultures, the risk for the recipient is unknown and there is no consensus for prescribing prophylactic antibiotics. This nationwide observational study aimed to determine the epidemiology of bacterial and fungal agents in kidney transplant PF cultures and identify risk factors associated with positive PF cultures.

METHODS

We performed a retrospective observational study on the following data collected from a national database between October 2015 and December 2016: characteristics of donor, recipient, transplantation, infection in donor and PF microbiological data.

RESULTS

Of 4487 kidney transplant procedures, including 725 (16.2%, 725/4487) from living donors, 20.5% had positive PF cultures (living donors: 1.8%, 13/725; deceased donors: 24.1%, 907/3762). Polymicrobial contamination was found in 59.9% (485/810) of positive PF cultures. Coagulase-negative staphylococci (65.8%, 533/810) and Enterobacteriaceae (28.0%, 227/810) were the most common microorganisms. Factors associated with an increased risk of positive PF cultures in multivariable analysis were (for deceased-donor kidney transplants): intestinal perforation during procurement (OR 4.4, 95% CI 2.1-9.1), multiorgan procurement (OR 1.4, 95% CI 1.1-1.7) and en bloc transplantation (OR 2.5, 95% CI 1.3-4.9). Use of perfusion pump and donor antibiotic therapy were associated with a lower risk of positive PF cultures (OR 0.4, 95% CI 0.3-0.5 and OR 0.6, 95% CI 0.5-0.7, respectively).

CONCLUSION

In conclusion, 24% of deceased-donor PF cultures were positive, and PF contamination during procurement seemed to be the major cause.

Post-Streptococcal Glomerulonephritis in Two Patients Following Deceased Donor Kidney Transplant

Patient: Female, 25

Final Diagnosis: Post-streptococcal glomerulonephritis

Symptoms: Elevated creatinine

Medication: —

Clinical Procedure: —

Specialty: Nephrology

Infectious Disease Transmission in Solid Organ Transplantation: Donor Evaluation, Recipient Risk, and Outcomes of Transmission

In 2016, the Transplantation Society of Australia and New Zealand, with the support of the Australian Government Organ and Tissue authority, commissioned a literature review on the topic of infectious disease transmission from deceased donors to recipients of solid organ transplants. The purpose of this review was to synthesize evidence on transmission risks, diagnostic test characteristics, and recipient management to inform best-practice clinical guidelines. The final review, presented as a special supplement in Transplantation Direct, collates case reports of transmission events and other peer-reviewed literature, and summarizes current (as of June 2017) international guidelines on donor screening and recipient management. Of particular interest at the time of writing was how to maximize utilization of donors at increased risk for transmission of human immunodeficiency virus, hepatitis C virus, and hepatitis B virus, given the recent developments, including the availability of direct-acting antivirals for hepatitis C virus and improvements in donor screening technologies. The review also covers emerging risks associated with recent epidemics (eg, Zika virus) and the risk of transmission of nonendemic pathogens related to donor travel history or country of origin. Lastly, the implications for recipient consent of expanded utilization of donors at increased risk of blood-borne viral disease transmission are considered.

Clinical Vignettes: Donor-Derived Infections

Patients undergoing solid organ transplantation (SOT) may acquire infections from the transplanted organ. Routine screening for common infections are an established part of the pretransplant evaluation of donors and recipients. Likewise, strategies exist for prophylaxis and surveillance for common donorassociated infections including hepatitis B, CMV and EBV. However, despite advances in diagnostic testing to evaluate the infectious risk of donors, unanticipated transmission of pathogens occurs, particularly when donors are asymptomatic or have subtle or unusual manifestations of a transmissible Infection. Infectious diseases (ID) providers play an integral role in donor and recipient risk assessment and can advise transplant centers on organ utilization and guide evaluation and management of the SOT recipient. Consideration of the donor cause of death and preceding clinical syndromes are important for characterizing the potential risk for recipient infection. This allows a more accurate analysis of the risk: benefit of accepting a life-saving organ and risk of infection. ID providers and transplant teams should work closely with organ procurement organizations (OPOs) to solicit additional donor information when a donor-derived infection is suspected so that reporting can be facilitated to ensure communication with the care-teams of other organ recipients from the same donors. National advisory committees work closely with federal agencies to provide oversight, guide policy development, and assess outcomes to assist with the prevention and management of donor-transmitted disease through organ transplantation. The clinical vignettes in this review highlight some of the complexities in the evaluation of potential donor transmission.

Outcome of pediatric heart transplantation in blood culture positive donors in the United States

Active donor infection at the time of organ procurement poses a potential infection risk and may increase post-transplant morbidity and mortality in recipients. Our hypothesis was that pediatric heart transplant recipients from blood culture positive donors (BCPD) would have increased morbidity and mortality compared to non-blood culture positive donors (NBCPD). A retrospective analysis of pediatric heart transplant recipients using the organ procurement and transplant network (OPTN) between 1987 and 2015 was conducted. Recipient as well as donor data were analyzed. Propensity score matching with 1:2 ratios was performed for recipient variables. Post-transplant morbidity and mortality were compared for recipients of BCPD and NBCPD. Among 9618 heart transplant recipients, 450 (4.7%) were from culture positive donors. Recipients of BCPD had longer duration of listing as Status 1; diagnosis of congenital heart disease or restrictive cardiomyopathy and required support (IV inotropes, Inhaled NO and LVAD) prior to transplant. Post-transplant survival between the 2 groups was not different. Propensity-matched recipients had similar length of stay; stroke rate; need for dialysis; pacemaker implantation and treated rejection episodes in the first year post-transplant. Careful acceptance of BCPD may have the potential to increase availability of donor hearts in the pediatric population.

Donor-Transmitted Bacterial Infection in Deceased Donor Liver Transplantation: Experience of Southern Taiwan Medical Center

BACKGROUND

Bacterial Infection is the most important source of mortality and morbidity in liver transplantation recipients. Donor transmitted bacterial infection is rare but one of the most important infection sources. This kind of infection is difficult to identify, causing treatment dilemma.

PATIENTS AND METHODS

In this article, we retrospectively reviewed our deceased donor liver transplants performed from January 2014 to December 2016. Forty-two recipients in Kaohsiung Chang Gung Memorial Hospital receiving liver grafts from 35 deceased liver donors were evaluated. The demography, donor transmitted infection, and outcomes were evaluated.

RESULT

Two patients had probable donor transmitted bacterial infection and 1 patient died of suspected transmitted infection.

CONCLUSION

Early identification of donor infection and adequate antibiotic treatment for the donor and recipient are the keys to preventing donor transmitted bacterial infection. Donor infection is not an absolute contraindication for organ donation in the area of organ shortage. Organ procurement organizations or similar authorities may establish the platform for sharing the data about donor and recipient infections.

Potential yield of imminent death kidney donation

About 99 000 people are waiting for a kidney in the United States, and many will die waiting. The concept of "imminent death" donation, a type of living donation, has been gaining attention among physicians, patients, and ethicists. We estimated the number of potential imminent death kidney donors at the University of Wisconsin Hospital and Clinics by assessing the number of annual deaths in individuals with normal kidney function. Based on a previous survey suggesting that one-third of patients might be willing to donate at imminent death, we estimate that between 76 and 396 people in the state of Wisconsin would be medically eligible and willing to donate each year at the time of imminent death. We extrapolated these numbers to all transplant centers in the United States, estimating that between 5925 and 31 097 people might be eligible and willing to donate each year. Our results suggest that allowing donation at imminent death and including discussions about organ donation in end-of-life planning could substantially reduce the nation's kidney waiting list while providing many more donors the opportunity to give this gift.

Infection in Kidney Transplantation

Infection is an important cause of morbidity and mortality after kidney transplantation. It has been estimated that 70% of kidney transplant recipients will experience an infection episode within the first 3 years after transplantation (Dharnidharka et al. 2007). After cardiovascular disease, infection is the second leading cause of death in recipients with allograft function (Snyder et al. 2009). The immunosuppressive therapy required to prevent organ rejection places the kidney transplant recipient at increased risk for donor-derived, nosocomial, and community-acquired infections as well as reactivation of latent pathogens. Pretransplant screening, immunizations, and optimal antibacterial and antiviral prophylaxis can help to reduce the impact of infection. Awareness of the approach to infection in the transplant recipient including diagnostic and management strategies is essential to optimizing outcomes.

The Care of the Postliver Transplant Patient

Since 1988 nearly 150,000 liver transplants have been performed in the United States. Over the past 3 decades the indications for liver transplant have changed from end-stage liver disease from alcohol and cholestatic liver diseases to hepatitis C and most recently nonalcoholic fatty liver disease. Liver transplant recipients are living longer with 10-year survival rates exceeding 60%. Gastroenterologists are likely to encounter or consult on postliver transplant recipients as they live longer and seek care closer to home. Complications after liver transplant are related to immunosuppression, malignancy, recurrent disease, and conditions associated with metabolic syndrome. This review will discuss postliver transplant care and complications in liver transplant recipients.

Infections in pediatric solid-organ transplant recipients

Solid-organ transplantation in pediatrics can be a life-saving procedure, but it cannot be accomplished without risk of infection-related morbidity and mortality. Evaluation of the recipient during candidacy and donor during evaluation can assist with identification of risk. Further, risk of infection from the surgical procedure can be mitigated through careful planning and attention to infection prevention processes. Finally, early recognition of infection posttransplant can limit the impact of these events.

Disruption of Transplant Tolerance by an "Incognito" Form of CD8 T Cell-Dependent Memory

Several approaches successfully achieve allograft tolerance in preclinical models but are challenging to translate into clinical practice. Many clinically relevant factors can attenuate allograft tolerance induction, including intrinsic genetic resistance, peritransplant infection, inflammation, and preexisting antidonor immunity. The prevailing view for immune memory as a tolerance barrier is that the host harbors memory cells that spontaneously cross-react to donor MHC antigens. Such preexisting "heterologous" memory cells have direct reactivity to donor cells and resist most tolerance regimens. In this study, we developed a model system to determine if an alternative form of immune memory could also block tolerance. We posited that host memory T cells could potentially respond to donor-derived non-MHC antigens, such as latent viral antigens or autoantigens, to which the host is immune. Results show that immunity to a model nonself antigen, ovalbumin (OVA), can dramatically disrupt tolerance despite undetectable initial reactivity to donor MHC antigens. Importantly, this blockade of tolerance was CD8⁺ T cell-dependent and required linked antigen presentation of alloantigens with the test OVA antigen. As such, this pathway represents an unapparent, or "incognito," form of immunity that is sufficient to prevent tolerance and that can be an unforeseen additional immune barrier to clinical transplant tolerance.

Guidelines for the assessment and acceptance of potential brain-dead organ donors

Organ transplantation is the only alternative for many patients with terminal diseases. The increasing disproportion between the high demand for organ transplants and the low rate of transplants actually performed is worrisome. Some of the causes of this disproportion are errors in the identification of potential organ donors and in the determination of contraindications by the attending staff. Therefore, the aim of the present document is to provide guidelines for intensive care multi-professional staffs for the recognition, assessment and acceptance of potential organ donors.

Severe Bloodstream Infection due to KPC-Producer E coli in a Renal Transplant Recipient Treated With the Double-Carbapenem Regimen and Analysis of In Vitro Synergy Testing: A Case Report

Transplant recipients are at high risk of infections caused by multidrug resistant microorganisms. Due to the limited therapeutic options, innovative antimicrobial combinations against carbapenem-resistant Enterobacteriaceae causing severe infections are necessary.A 61-year-old woman with a history of congenital solitary kidney underwent renal transplantation. The postoperative course was complicated by nosocomial pneumonia due to Stenotrophomonas maltophilia and pan-sensitive Escherichia coli, successfully treated with antimicrobial therapy. On postoperative day 22, diagnosis of surgical site infection and nosocomial pneumonia with concomitant bacteremia due to a Klebisella pneumoniae carbapenemase-producer E coli was made. The patient was treated with the double-carbapenem regimen (high dose of meropenem plus ertapenem) and a potent synergistic and bactericidal activity of this un-conventional therapeutic strategy was observed in vitro. Despite a microbiological response with prompt negativity of blood cultures, the patient faced a worse outcome because of severe hemorrhagic shock.The double-carbapenem regimen might be considered as a rescue therapy in those subjects, including transplant recipients, in whom previous antimicrobial combinations failed or when colistin use might be discouraged. Performing in vitro synergy testing should be strongly encouraged in cases of infections caused by pan-drug resistant strains, especially in high-risk patients.

Necessities for a Clinical Islet Program

For more than two decades we have been refining advances in islet cell transplantation as a clinical therapy for patients suffering from type 1 diabetes. A great deal of effort has gone to making this a viable therapy for a broader range of patients with type 1 diabetes. Clinical results have progressively improved, demonstrating clinical outcomes on par with other organ transplants, specifically in terms of insulin independence, graft and patient survival. We are now at the point where islet cell transplantation, in the form of allotransplantation, has become accepted as a clinical therapy in adult patients affected by type 1 diabetes, in particular those suffering from severe hypoglycaemic unawareness. This chapter provides an overview on how this has been undertaken over the years to provide outcomes on par with other organ transplantation results. In particular this chapter focuses on the processes and facilities that are required to establish a clinical islet isolation and transplantation program. It also outlines the very important underpinning processes of selection of the organ donor for islet isolation, the processes of organ donor operation and preservation of the pancreas by various means and the ideal ways to best improve outcomes for human islet cell isolation. Providing these more optimal conditions we can underpin the isolation processes to provide islets for transplantation and as such a safe, effective and feasible therapeutic option for an increasing number of patients suffering from type 1 diabetes with severe hypoglycaemic unawareness.