Introduction: Infections in solid organ transplantation

Monocentric, Retrospective Study on Infectious Complications within One Year after Solid-Organ Transplantation at a Belgian University Hospital

The epidemiology, diagnostic methods and management of infectious complications after solid-organ transplantation (SOT) are evolving. The aim of our study is to describe current infectious complications in the year following SOT and risk factors for their development and outcome. We conducted a retrospective study in adult SOT recipients in a Belgian university hospital between 2018 and 2019. We gathered demographic characteristics, comorbidities leading to transplantation, clinical, microbiological, surgery-specific and therapeutic data concerning infectious episodes, and survival status up to one year post-transplantation. Two-hundred-and-thirty-one SOT recipients were included (90 kidneys, 79 livers, 35 lungs, 19 hearts and 8 multiple organs). We observed 381 infections in 143 (62%) patients, due to bacteria (235 (62%)), viruses (67 (18%)), and fungi (32 (8%)). Patients presented a median of two (1-5) infections, and the first infection occurred during the first six months. Nineteen (8%) patients died, eleven (58%) due to infectious causes. Protective factors identified against developing infection were obesity [OR [IC]: 0.41 [0.19-0.89]; p = 0.025] and liver transplantation [OR [IC]: 0.21 [0.07-0.66]; p = 0.007]. Risk factors identified for developing an infection were lung transplantation [OR [IC]: 6.80 [1.17-39.36]; p = 0.032], CMV mismatch [OR [IC]: 3.53 [1.45-8.64]; p = 0.006] and neutropenia [OR [IC]: 2.87 [1.27-6.47]; p = 0.011]. Risk factors identified for death were inadequate cytomegalovirus prophylaxis, infection severity and absence of pneumococcal vaccination. Post-transplant infections were common. Addressing modifiable risk factors is crucial, such as pneumococcal vaccination.

Infections in Heart and Lung Transplant Recipients

Infections in heart and lung transplant recipients are complex and heterogeneous. This article reviews the epidemiology, risk factors, specific clinical syndromes, and most frequent opportunistic infections in heart and/or lung transplant recipients that will be encountered in the intensive care unit and will provide a practical approach of empirical management.

A quick algorithmic review on management of viral infectious diseases in pediatric solid organ transplant recipients

Pediatric solid organ transplant is a life-saving procedure for children with end-stage organ failure. Viral infections are a common complication following pediatric solid organ transplantation (SOT), which can lead to increased morbidity and mortality. Pediatric solid organ transplant recipients are at an increased risk of viral infections due to their immunosuppressed state. The most commonly encountered viruses include cytomegalovirus (CMV), Epstein-Barr virus (EBV), herpes simplex virus (HSV), varicella-zoster virus (VZV), adenoviruses, and BK polyomavirus. Prevention strategies include vaccination prior to transplantation, post-transplant prophylaxis with antiviral agents, and preemptive therapy. Treatment options vary depending on the virus and may include antiviral therapy and sometimes immunosuppression modification. This review provides a Quick Algorithmic overview of prevention and treatment strategies for viral infectious diseases in pediatric solid organ transplant recipient.

Comparison of the Prolonged- and Immediate-Release Tacrolimus Capsule Formulation: The Patient's View and Medication Satisfaction of Patients After Pediatric Heart Transplantation

BACKGROUND

Medication adherence is essential for long-term success after pediatric organ transplantation. Causes of reduced adherence should be detected early to improve the consequent medication intake. We describe the influence of switching from tacrolimus twice daily (tacrolimus-BID) to tacrolimus once daily (tacrolimus-QD) on medication satisfaction and medication adherence in patients after pediatric heart transplantation.

METHODS

A retrospective analysis was conducted regarding patient satisfaction and adherence to the immunosuppressant tacrolimus after pediatric heart transplantation, before and after conversion from tacrolimus-BID to tacrolimus-QD, using questionnaires.

RESULTS

Thirty-eight patients were enrolled (tacrolimus-BID: n = 35, mean age 15.7 ± 5.2 years; tacrolimus-QD: n = 38, mean age 16.2 ± 5.6 years). The amount of unadministered medication in the last 3 months did not differ between the 2 pharmaceutical forms. However, 17% (n = 6) reported unstable tacrolimus trough levels when taking tacrolimus-BID, vs 8% (n = 3) under tacrolimus-QD (P = .453). However, there was no statistically significant difference in the stability of the last 6 trough levels of each patient (P = .074). A total of 57% (n = 20) of patients had subjective side effects before conversion, compared to only 29% (n = 11) after conversion (P = .013). Regarding the intensity of the side effects, 6 patients reported strong/very strong side effects when taking tacrolimus-BID vs 1 patient when taking tacrolimus-QD (P = .250). In addition, the overall satisfaction with the immunosuppressant was higher under tacrolimus-QD (92% vs 83%; P = .508). However, this improvement was statistically not significant and may not be clinically relevant.

CONCLUSIONS

The amount of forgotten medication was not reduced after conversion from tacrolimus-BID to tacrolimus-QD. However, subjective side effects as well as patient satisfaction improved under tacrolimus-QD.

Applying Rituximab During the Conditioning Regimen Prevents Epstein-Barr Virus Infection Following Allogeneic Hematopoietic Stem Cell Transplant in a Children's Cohort: A Retrospective Case-Control Study

INTRODUCTION

Since hematopoietic stem cell transplant (HSCT) is an important therapy for malignant and non-malignant pediatric diseases, improving transplant-related mortality remains a challenge. Currently, rituximab, a monoclonal antibody of anti-CD20, is widely used for several post-HSCT complications. However, few studies have focused on the application of rituximab before HSCT.

METHODS

We conducted a retrospective case-control study from January 2019 to July 2021 to determine this effect in a single center. Forty-eight patients were included in the rituximab group, with a one-to-one ratio matched to the control group.

RESULTS

Both the occurrence rate and cumulative incidence rate of Epstein-Barr virus (EBV) infection were significantly lower in the rituximab group than in the without-rituximab group (10.4% vs. 33.3%, p = 0.014 and 12.2% vs. 39.3% p = 0.0026, respectively). Furthermore, without the application of rituximab was identified as a risk factor for post-HSCT EBV infection via both univariate [hazard ratio (HR) = 4.17, 95%CI (1.52-11.43), p = 0.005] and multivariate analyses [HR = 4.65, 95%CI (1.66-13.0), p = 0.003]. Although the overall survival (OS) probability of the rituximab group was comparable to the without-rituximab group, a markedly improved OS of the rituximab group was found in the malignant disease subgroup (78.9% vs. 42.1%, p = 0.032). The outcomes of graft-versus-host disease, neutrophil and platelet engraftment, other viral infections, and the reconstitution of lymphocytes showed no significant differences between the two groups.

CONCLUSIONS

The administration of rituximab before HSCT may prevent EBV infection following HSCT.

Minimizing the Risk of Donor-Derived Events and Maximizing Organ Utilization Through Education and Policy Development

Herein, we review the current knowledge of donor-derived disease and current US Organ Procurement and Transplantation Network policies to minimize the risk. During the process, we also consider actions to further mitigate the risk of donor-derived disease. The overarching goal is to provide an infectious disease perspective on the complex decision of organ acceptance for transplant programs and candidates.

Radiometal chelators for infection diagnostics

Infection of native tissues or implanted devices is common, but clinical diagnosis is frequently difficult and currently available noninvasive tests perform poorly. Immunocompromised individuals (for example transplant recipients, or those with cancer) are at increased risk. No imaging test in clinical use can specifically identify infection, or accurately differentiate bacterial from fungal infections. Commonly used [18F]fluorodeoxyglucose (18FDG) positron emission computed tomography (PET/CT) is sensitive for infection, but limited by poor specificity because increased glucose uptake may also indicate inflammation or malignancy. Furthermore, this tracer provides no indication of the type of infective agent (bacterial, fungal, or parasitic). Imaging tools that directly and specifically target microbial pathogens are highly desirable to improve noninvasive infection diagnosis and localization. A growing field of research is exploring the utility of radiometals and their chelators (siderophores), which are small molecules that bind radiometals and form a stable complex allowing sequestration by microbes. This radiometal-chelator complex can be directed to a specific microbial target in vivo, facilitating anatomical localization by PET or single photon emission computed tomography. Additionally, bifunctional chelators can further conjugate therapeutic molecules (e.g., peptides, antibiotics, antibodies) while still bound to desired radiometals, combining specific imaging with highly targeted antimicrobial therapy. These novel therapeutics may prove a useful complement to the armamentarium in the global fight against antimicrobial resistance. This review will highlight current state of infection imaging diagnostics and their limitations, strategies to develop infection-specific diagnostics, recent advances in radiometal-based chelators for microbial infection imaging, challenges, and future directions to improve targeted diagnostics and/or therapeutics.

NPP-669, a Novel Broad-Spectrum Antiviral Therapeutic with Excellent Cellular Uptake, Antiviral Potency, Oral Bioavailability, Preclinical Efficacy, and a Promising Safety Margin

DNA viruses are responsible for many diseases in humans. Current treatments are often limited by toxicity, as in the case of cidofovir (CDV, Vistide), a compound used against cytomegalovirus (CMV) and adenovirus (AdV) infections. CDV is a polar molecule with poor bioavailability, and its overall clinical utility is limited by the high occurrence of acute nephrotoxicity. To circumvent these disadvantages, we designed nine CDV prodrug analogues. The prodrugs modulate the polarity of CDV with a long sulfonyl alkyl chain attached to one of the phosphono oxygens. We added capping groups to the end of the alkyl chain to minimize β-oxidation and focus the metabolism on the phosphoester hydrolysis, thereby tuning the rate of this reaction by altering the alkyl chain length. With these modifications, the prodrugs have excellent aqueous solubility, optimized metabolic stability, increased cellular permeability, and rapid intracellular conversion to the pharmacologically active diphosphate form (CDV-PP). The prodrugs exhibited significantly enhanced antiviral potency against a wide range of DNA viruses in infected human foreskin fibroblasts. Single-dose intravenous and oral pharmacokinetic experiments showed that the compounds maintained plasma and target tissue levels of CDV well above the EC50 for 24 h. These experiments identified a novel lead candidate, NPP-669. NPP-669 demonstrated efficacy against CMV infections in mice and AdV infections in hamsters following oral (p.o.) dosing at a dose of 1 mg/kg BID and 0.1 mg/kg QD, respectively. We further showed that NPP-669 at 30 mg/kg QD did not exhibit histological signs of toxicity in mice or hamsters. These data suggest that NPP-669 is a promising lead candidate for a broad-spectrum antiviral compound.

Infections following rejection therapies in kidney and liver transplant recipients

INTRODUCTION

Infections are known complications of solid-organ transplant. Treatment for rejection may increase risk of infection. We aimed to study frequency of infection and identify the risk factors for infections in solid organ transplant (SOT) (liver and kidney) recipients treated for rejection.

METHODS

This is a retrospective chart review of all liver and kidney transplant recipients treated for rejection at our institution from 2014 to 2020. We collected information on episodes of acute rejection in the first year of transplant and infections within 6 months following rejection treatment.

RESULTS

We identified 257 transplant patients treated for rejection. One hundred twelve (43.6%) developed infections, with a total of 226 infections. Urinary tracts infections were the most common, 72 (31.9%), followed by cytomegalovirus viremia in 37 (16.4%), bacteremia in 24 (10.6%), and BK virus in 14 (6.2%). Female sex (p = .047), elevated neutrophil count at rejection (p = .002), and increased number of rejection episodes (p = .022) were predictors of infection in kidney and simultaneous liver-kidney recipients. No specific type of induction or rejection therapy was identified as a risk factor for infection, likely due to the prophylaxis protocols at our institution. Infection post rejection treatment was associated with higher graft loss (p = .021) and mortality (p = .031) in kidney transplant recipients.

CONCLUSIONS

Infections are common complications after treatment of SOT rejection. Female gender, higher neutrophil at time of rejection, and increased numbers of rejection episodes were predictors of infections after rejection in simultaneous liver-kidney and kidney transplant patients. Infections were predictors of graft loss at 6 months and mortality at any point in follow-up in kidney transplant patients.

Cladophialophora Bantiana Brain Abscess and Concurrent Pulmonary Cryptococcus Neoformans Infection in a Patient Twenty Years After Renal Transplantation

Recipients of solid organ transplants are at risk for a variety of infections due to their immunocompromised status. The types of infections are often correlated to the timing from their transplant. After about six to twelve months, transplant recipients remain at risk for typical community acquired pathogens, late viral infections, and fungal infections including atypical molds such as Cladophialophora bantiana. C. bantiana is a dematiaceous fungus that has a predilection for infecting the brain and is the most common cause of cerebral phaeohyphomycosis - a term used to describe infections caused by molds that produce dark cell walls. Patients with cerebral abscesses due to C. bantiana infections have an estimated mortality of about 70%. Improved outcomes have been seen in patients who receive both surgical and antifungal therapy. While there are no clear guidelines on antifungal therapy, most cases have been treated with combination amphotericin B, a triazole (itraconazole, voriconazole, or posaconazole) with flucytosine sometimes in conjunction as well. This case describes a patient with C. bantiana brain abscess and concurrent Cryptococcus neoformans pulmonary infection that occurred twenty years after his kidney transplantation. He was treated successfully with two craniotomies for cerebral abscess debridement and liposomal amphotericin B followed by planned lifelong voriconazole.

Bacterial and fungal bloodstream infections in solid organ transplant recipients: results from a Danish cohort with nationwide follow-up

OBJECTIVES

Bloodstream infections (BSI) are prevalent after solid organ transplantation (SOT). In this study, we aimed to investigate the incidence and risk factors for BSI in the first 5 years post-transplantation.

METHODS

The study included 1322 SOT (kidney, liver, lung and heart) recipients transplanted from 2010 to 2017 with a total of 5616 years of follow-up. Clinical characteristics and microbiology were obtained from the Centre of Excellence for Personalized Medicine of Infectious Complications in Immune Deficiency (PERSIMUNE) data repository with nationwide follow-up. Incidence was investigated in the different SOT groups. Risk factors associated with BSI were assed in the combined group in time-updated multivariable Cox regressions.

RESULTS

The cumulative incidence of first BSI in the first 5 years post-transplantation differed in the SOT groups with a lower incidence in heart transplant recipients than in the other SOT groups (heart: 4.4%, CI 0.0-9.7%, vs. kidney: 24.6%, CI 20.9-28.2%, liver: 24.7%, CI 19.4-29.9%, and lung: 19.6%, CI 14.5-24.8%, p <0.001). Age above 55 years (HR 1.71, CI 1.2-2.4, p=0.002) and higher Charlson comorbidity index score (HR per unit increase: 1.25, CI 1.1-1.4, p<0.001) at transplantation, current cytomegalovirus (CMV) infection (HR 4.5, CI 2.6-7.9, p<0.001) and current leucopenia (HR 13.3, CI 3.7-47.9, p<0.001) were all associated with an increased risk of BSI.

CONCLUSION

In SOT recipients, the incidence of BSI differed with the type of transplanted organ. Risk of BSI was higher in older recipients and in recipients with comorbidity, current CMV infection or leucopenia. Thus, increased attention towards BSI in recipients with these characteristics is warranted.

Pneumococcal pneumonia in adult hospitalised solid organ transplant recipients: Nationwide, population-based surveillance

BACKGROUND

Pneumococcal disease poses a burden to the community in high risk population. Most early studies focused on invasive pneumococcal disease. However, the epidemiology of pneumococcal pneumonia (PP) requiring hospitalisation in solid organ transplant recipients (SOTRs) is poorly defined.

METHODS

We conducted a retrospective cohort study (January 1, 2000 and December 31, 2012) to evaluate the risk of PP requiring hospitalisation in SOTRs. SOTRs and non-SOT cohorts, propensity score-matched at a 1:1 ratio for age, sex, index date and underlying comorbidities, were identified from the National Health Insurance Research Database.

RESULTS

Each cohort consisted of 7507 patients. In the SOT cohort, 26 episodes of PP requiring hospitalisation were identified (incidence rate of 52.4 per 100,000 person-years). The risk of PP requiring hospitalisation in the SOT cohort was 1.50 times greater than in the non-SOT cohort [adjusted hazard ratio: 1.50, 95% confidence interval = 1.31-1.71, P < .001]. The nested case control study identified older age, kidney transplant, and concomitant chronic obstructive pulmonary disease, chronic kidney disease and heart failure as predictors of PP requiring hospitalisation in the SOT cohort. The highest risk period for PP requiring hospitalisation occurred within the first year of transplantation (36.47 per 1000 patients). Amongst kidney transplant recipients, patients with PP requiring hospitalisation exhibited higher cumulative incidences of graft failure than those without PP (log-rank test: P value = .004).

CONCLUSIONS

SOTRs are at risk of PP requiring hospitalisation with its attendant morbidity. Strategies to reduce risk of PP requiring hospitalisation using preventive vaccinations warrant further study.

Burden and Timeline of Infectious Diseases in the First Year After Solid Organ Transplantation in the Swiss Transplant Cohort Study

Background

The burden and timeline of posttransplant infections are not comprehensively documented in the current era of immunosuppression and prophylaxis.

Methods

In this prospective study nested within the Swiss Transplant Cohort Study (STCS), all clinically relevant infections were identified by transplant–infectious diseases physicians in persons receiving solid organ transplant (SOT) between May 2008 and December 2014 with ≥12 months of follow-up.

Results

Among 3541 SOT recipients, 2761 (1612 kidney, 577 liver, 286 lung, 213 heart, and 73 kidney-pancreas) had ≥12 months of follow-up; 1520 patients (55%) suffered 3520 infections during the first year posttransplantation. Burden and timelines of clinically relevant infections differed between transplantations. Bacteria were responsible for 2202 infections (63%) prevailing throughout the year, with a predominance of Enterobacteriaceae (54%) as urinary pathogens in heart, lung, and kidney transplant recipients, and as digestive tract pathogens in liver transplant recipients. Enterococcus spp (20%) occurred as urinary tract pathogens in kidney transplant recipients and as digestive tract pathogens in liver transplant recipients, and Pseudomonas aeruginosa (9%) in lung transplant recipients. Among 1039 viral infections, herpesviruses predominated (51%) in kidney, liver, and heart transplant recipients. Among 263 fungal infections, Candida spp (60%) prevailed as digestive tract pathogens in liver transplant recipients. Opportunistic pathogens, including Aspergillus fumigatus (1.4%) and cytomegalovirus (6%), were rare, scattering over 12 months across all SOT recipients.

Conclusions

In the current era of immunosuppression and prophylaxis, SOT recipients experience a high burden of infections throughout the first year posttransplantation, with rare opportunistic pathogens and a predominance of bacteria.

Preventing Coronavirus Disease 2019 in Kidney Transplant Recipients: Where Should We Begin?

Context

Chronic immunosuppression is associated with an increased risk of opportunistic infections. Although kidney transplant recipients with coronavirus disease 2019 (COVID-19) have higher mortality than the general population, data on their risk of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are unknown.

Subject of Review

A recent single-center screening study from the UK (Transplantation. 2021 Jan 1;105(1):151–7) showed that 89 (10.4%) of 855 consecutive kidney transplant recipients tested positive for SARS-CoV-2 antibodies. Risk factors for infection included a nonwhite background, diabetes, and a history of allograft rejection. Risk factors for mortality in individuals who developed COVID-19 were older age and receiving steroids.

Second Opinion

This study shows that the rate of SARS-CoV-2 infection in kidney transplant recipients is similar to the one observed in the general population in the same area (13%), indicating that transplant recipients are not at increased risk of COVID-19. However, the investigators raise the interesting point that since transplant individuals were advised to shelter earlier than the general population, they may be in fact more susceptible. This statement is hard to substantiate, but the identification of specific risk factors for infection and poor outcomes is crucial to tailor strategies to prevent spread of the infection. This is particularly important, considering that kidney transplant recipients may be at increased risk of prolonged viral spread and in-host viral mutations, making them not just a particularly fragile population for COVID-19 but also a potentially major source of further contagions.

Relative Frequency of Blood-Borne Viruses in Hemodialysis-Dependent and Kidney Transplant Recipients in Iran

Background:

Hemodialysis (HD) patients and kidney transplant (KT) recipients are exposed to be infected by blood-borne viruses (BBVs). Current study was conducted to evaluate the prevalence of BBVs in HD and KT patients in the whole Iranian population.

Methods:

From Jan 2016 to Dec 2017, 174 hemodialysis and 139 kidney transplant recipients enrolled in this survey. After blood sampling, serum samples were detected for HBV, HCV, HCMV, HIV and HTLV antibodies. Seropositive samples confirmed by Polymerase chain reaction (PCR) method.

Results:

Overall, 6 (3.44%) and 3 (2.15%) of hemodialysis-dependent and transplantation patients had evidence of HCV infection, whereas no patients were HIV and HBV positive, two cases (1.14%) of hemodialysis and one case (0.71%) of transplantation patients demonstrated the HTLV-1 infection. 52 (37.4%) of patients received graft were positive for HCMV antibody. In addition, our study showed a co-infection of HCMV with HCV (3 patients, 2.15%) in transplantation patients.

Conclusion:

Prevalence of BBVs infection was lower in comparison to the previous studies. The current strict infection control practices in Iran appear to be effective in limiting dialysis and related infections after transplantation. Because BBVs infections constantly occur especially in dialysis and after transplantation units, our data will be useful to build a new strategic plan for the elimination of BBVs infection in kidney therapycenters.

Sepsis in Immunocompromised Patients Without Human Immunodeficiency Virus

Sepsis remains among the most common complications from infectious diseases worldwide. The morbidity and mortality rates associated with sepsis range from 20% to 50%. The advances in care for patients with an immunocompromised status have been remarkable over the last 2 decades, but sepsis continues to be a major cause of death in this population Immunocompromised patients who are recipients of a solid organ or hematopoietic stem cell transplant are living longer with a better quality of life. However, some of these patients need lifelong treatment with immunosuppressive medications to maintain their transplant status. A consequence of the need for this permanent immunosuppression is the high risk of opportunistic, community, and hospital-acquired infections, all of which can lead to sepsis. In addition, the detection of serious infections may be more challenging owing to patients' lower ability to mount the clinical symptoms that usually accompany sepsis. This article provides an update on the current knowledge of sepsis in immunocompromised patients without human immunodeficiency virus. It reviews the most pertinent causes of sepsis in this population, and addresses the specific diagnostic and therapeutic challenges in neutropenia and solid organ and hematopoietic stem cell transplantation.

A Large-Scale Bank of Organ Donor Bone Marrow and Matched Mesenchymal Stem Cells for Promoting Immunomodulation and Transplant Tolerance

Induction of immune tolerance for solid organ and vascular composite allografts is the Holy Grail for transplantation medicine. This would obviate the need for life-long immunosuppression which is associated with serious adverse outcomes, such as infections, cancers, and renal failure. Currently the most promising means of tolerance induction is through establishing a mixed chimeric state by transplantation of donor hematopoietic stem cells; however, with the exception of living donor renal transplantation, the mixed chimerism approach has not achieved durable immune tolerance on a large scale in preclinical or clinical trials with other solid organs or vascular composite allotransplants (VCA). Ossium Health has established a bank of cryopreserved bone marrow (BM), termed "hematopoietic progenitor cell (HPC), Marrow," recovered from deceased organ donor vertebral bodies. This new source for hematopoietic cell transplant will be a valuable resource for treating hematological malignancies as well as for inducing transplant tolerance. In addition, we have discovered and developed a large source of mesenchymal stem (stromal) cells (MSC) tightly associated with the vertebral body bone fragment byproduct of the HPC, Marrow recovery process. Thus, these vertebral bone adherent MSC (vBA-MSC) are matched to the banked BM obtained from each donor, as opposed to third-party MSC, which enhances safety and potentially efficacy. Isolation and characterization of vBA-MSC from over 30 donors has demonstrated that the cells are no different than traditional BM-MSC; however, their abundance is >1,000-fold higher than obtainable from living donor BM aspirates. Based on our own unpublished data as well as reports published by others, MSC facilitate chimerism, especially at limiting hematopoietic stem and progenitor cell (HSPC) numbers and increase safety by controlling and/or preventing graft-vs.-host-disease (GvHD). Thus, vBA-MSC have the potential to facilitate mixed chimerism, promote complementary peripheral immunomodulatory functions and increase safety of BM infusions. Both HPC, Marrow and vBA-MSC have potential use in current VCA and solid organ transplant (SOT) tolerance clinical protocols that are amenable to "delayed tolerance." Current trials with HPC, Marrow are planned with subsequent phases to include vBA-MSC for tolerance of both VCA and SOT.

Induction of Allograft Tolerance While Maintaining Immunity Against Microbial Pathogens: Does Coronin 1 Hold a Key?

Selective suppression of graft rejection while maintaining anti-pathogen responses has been elusive. Thus far, the most successful strategies to induce suppression of graft rejection relies on inhibition of T-cell activation. However, the very same mechanisms that induce allograft-specific T-cell suppression are also important for immunity against microbial pathogens as well as oncogenically transformed cells, resulting in significant immunosuppression-associated comorbidities. Therefore, defining the pathways that differentially regulate anti-graft versus antimicrobial T-cell responses may allow the development of regimen to induce allograft-specific tolerance. Recent work has defined a molecular pathway driven by the immunoregulatory protein coronin 1 that regulates the phosphodiesterase/cyclic adenosine monophosphate pathway and modulates T cell responses. Interestingly, disruption of coronin 1 promotes allograft tolerance while immunity towards a range of pathogenic microbes is maintained. Here, we briefly review the work leading up to these findings as well as their possible implications for transplantation medicine.

Infectious disease considerations in immunocompromised patients

Immunocompromised patients account for about 3% of the US population. Complications arising from infection are common in these patients and can present diagnostic and therapeutic challenges. This article describes the pathophysiology of immunosuppression in five common immunocompromised states-asplenia, HIV infection, solid organ transplant, biologic use, and cancer-as well as specific infectious risks and considerations for affected patients and how to manage them.

Pneumococcal vaccination in lung transplant patients

Introduction: This review analyzes the efficacy of pneumococcal vaccinations in lung transplant patients before and after transplantation.Areas covered: This review addresses the risk for respiratory infections, in particular pneumococcal infections, in lung transplantation patients in the context of immunodeficiency and immunosuppressive medication. Vaccination is recommended to counteract the increased risk of pneumococcal infection, and the relevant guidelines are discussed in this review. The design of specific vaccination schedules is required because of the impaired antibody response in specific patient categories.Expert opinion: Lung transplantation candidates should be vaccinated with pneumococcal vaccines prior to transplantation. Currently, the 23-valent pneumococcal polysaccharide vaccine offers the broadest coverage, but the antibody response should be monitored. New generation pneumococcal conjugate vaccines with equally broad serotype coverage could be used in the future. During the post-transplantation period, the immune status of the patients should be monitored regularly, and vaccination should be repeated when indicated.

Skin Transplantation and Lymphoid Organ Analysis in Mice

Skin transplantation in mice is an important procedure to evaluate immune responses generated against heterologous grafts, especially given its highly immunogenic nature. In fact, skin is one of the most challenging organs in terms of allograft retention. In this protocol, we provide a detailed procedure for skin grafting using the tail skin as donor organ that is grafted on the dorsal site of thoracic cage in a recipient mouse. We also provide protocols for the systematic analysis of lymphoid organ analysis in transplanted mice. Together these protocols may be valuable for evaluation of parameters that affect skin grafting, including genetic factors, immune cell activation as well as the analysis of compounds that may be useful in allowing graft tolerance.

Causes of acute respiratory failure in the immunocompromised host

PURPOSE OF REVIEW

A wide spectrum of heterogeneous conditions can render a patient immunocompromised. Recent years have seen an increase in the number of immunocompromised patients given the earlier detection of conditions that require immunosuppressive therapies, changes in immunosuppressive regimens leading to increased survival or novel therapeutic advancements in oncologic care. Acute respiratory failure (ARF) is the leading cause of critical illness and mortality in this population. This review highlights the spectrum of causes of ARF in immunocompromised patients with a particular focus on acute toxicities of novel oncologic treatments.

RECENT FINDINGS

Recent years have seen improved survival amongst critically ill immunocompromised patients with ARF. This is likely attributable to patient selection of immunosuppressive therapy, improved noninvasive microbiologic diagnostic techniques, improved antimicrobial prophylaxis, treatment, stewardship, and advancements in supportive care including intensive care. Infectious complications remain the leading cause of ARF in this population. However, one of the greatest challenges physicians continue to face is accurate identification of the cause of ARF, given the vast (and increasing) noninfectious causes of ARF across these patients. Emerging therapies, such as immune checkpoint inhibitors (ICIs) and chimeric antigen receptor T-cell therapy (CAR T-cell) have contributed to this problem. Finally, undetermined ARF is reported in approximately 13% of immunocompromised and is associated with a worse prognosis.

SUMMARY

Infectious complications are still the leading cause of ARF in immunocompromised patients. However, noninfectious complications, derived from the underlying disease or treatment, should be always considered, including novel therapies, such as ICIs and CAR T cells. Further research should focus in improving the diagnostic rate in this subgroup.

Complications of total joint arthroplasty in solid organ transplant patients versus a large control group

BACKGROUND

Solid organ transplant patients are theoretically at increased risk for complications after total joint replacement due to immunosuppressive medication regimens and multiple medical co-morbidities. There are a number of studies that report on outcomes of total joint arthroplasty (TJA) following solid organ transplant, however, the results are heterogeneous. This study evaluated the outcomes of TJA in solid organ transplant patients as compared to non-organ transplant controls at one academic medical center.

METHODS

This study was a single institution retrospective review of a consecutive series of patients who underwent joint replacement following solid organ transplant as compared to a control cohort over a 10-year period. Univariable and multivariable generalized linear mixed effects models were used to compare the odds of readmission, infection, mortality, and being discharged home between transplanted (cases) and non-transplanted (control) patients.

RESULTS

Transplant and non-transplant cohorts had similar BMI, although transplant patients were younger (61 versus 65 years) and had a higher incidence of Diabetes (55% vs. 16%). On multivariable analysis, there was no difference in the odds of re-admission or rate of infection, but there was an increased risk of death and admission to a rehab facility in the transplant cohort.

CONCLUSION

Overall, this study demonstrates that solid organ transplant alone does not increase the risk of peri-operative complications in patients who underwent hip and knee replacement. However, it should be expected that these patients have a higher mortality rate and that many of them will need to be discharged to a post-acute care facility.

American Thoracic Society 2019 Pediatric Core Curriculum

The American Thoracic Society Pediatric Core Curriculum updates clinicians annually in pediatric pulmonary disease in a 3 to 4 year recurring cycle of topics. The 2019 course was presented in May during the Annual International Conference. An American Board of Pediatrics Maintenance of Certification module and a continuing medical education exercise covering the contents of the Core Curriculum can be accessed online at www.thoracic.org.

Post-transplant infection improves outcome of hepatocellular carcinoma patients after orthotopic liver transplantation

BACKGROUND

Tumor recurrence after orthotopic liver transplantation (OLT) remains a serious threat for long-term survival of the recipients with hepatocellular carcinoma (HCC), since very few factors or measures have shown impact on overcoming HCC recurrence after OLT. Postoperative infection suppresses tumor recurrence and improves patient survival in lung cancer and malignant glioma probably via stimulating the immune system. Post-transplant infection (PTI), a common complication, is deemed to be harmful for the liver transplant recipients from a short-term perspective. Nevertheless, whether PTI inhibits HCC recurrence after OLT and prolongs the long-term survival of HCC patients needs to be clarified.

AIM

To investigate the potential influence of PTI on the survival and tumor recurrence of patients with HCC after OLT.

METHODS

A total of 238 patients with HCC who underwent OLT between August 2002 and July 2016 at our center were retrospectively included and accordingly subdivided into a PTI group (53 patients) and a non-PTI group (185 patients). Univariate analyses, including the differences of overall survival (OS), recurrence-free survival (RFS), and post-recurrence survival (PRS), between the PTI and non-PTI subgroups as well as survival curve analysis were performed by the Kaplan-Meier method, and the differences were compared using the log rank test. The variables with a P-value < 0.1 in univariate analyses were included in the multivariate survival analysis by using a Cox proportional-hazards model.

RESULTS

The 1-, 3-, and 5-year OS and RFS rates of the whole cohort were 86.6%, 69.0%, and 63.6%, and 75.7%, 60.0%, and 57.3%, respectively. The 1-, 3-, and 5-year OS rates for the PTI patient group (96.0%, 89.3%, and 74.0%) were significantly higher than those for the non-PTI group (84.0%, 63.4%, and 60.2%) (P = 0.033). The absence of PTI was an independent risk factor for dismal OS (relative risk [RR] = 2.584, 95%CI: 1.226-5.449) and unfavorable RFS (RR = 2.683, 95%CI: 1.335-5.390). Subgroup analyses revealed that PTI remarkably improved OS (P = 0.003) and RFS (P = 0.003) rates of HCC patients with vascular invasion (IV), but did not impact on OS (P = 0.404) and RFS (P = 0.304) of patients without VI. Among the patients who suffered post-transplant tumor recurrence, patients with PTI showed significantly better OS (P = 0.026) and PRS (P = 0.042) rates than those without PTI.

CONCLUSION

PTI improves OS and RFS of the transplant HCC patients at a high risk for post-transplant death and tumor recurrence, which is attributed to suppressive effect of PTI on HCC recurrence.

Evaluation of the Renal Transplant Recipient in the Emergency Department

Renal transplants are becoming more and more frequent in the United States and worldwide. Studies demonstrate that these patients inevitably end up visiting an emergency department. In addition to typical medical and surgical problems encountered in the general population, this group of patients has unique problems arising from their immunocompromised state and also due to side effects of the medications required. This article discusses these risks and management decisions that the emergency department physician should be aware of in order to prevent adverse outcomes for the patient and transplanted kidney.

Immunosuppression following organ transplantation. Part 2: complications and their management

Advances in the care of patients who have had a solid organ transplant has led to a growing population of post-transplant patients, who are also living for longer. As a result of their longer life expectancy, transplant recipients often face a multitude of challenges, including optimising their immunosuppressive regimens and managing potential complications. Life-threatening infections, malignancies, and organ-specific toxicities are the complications post-transplant patients commonly encounter and these complications are often associated with increased morbidity and mortality, adverse graft functioning and survival, profound impairment in the patient's quality of life, and significant healthcare burden. This article, the second of two parts, gives an overview of the issues involved in the care of patients who are receiving immunosuppressants. The common complications encountered by post-transplant patients are discussed and their assessment, management, prevention and treatment explored.

Comparative transcriptome analysis of peripheral blood mononuclear cells in renal transplant recipients in everolimus- and tacrolimus-based immunosuppressive therapy

To better define the biological impact of immunosuppression on peripheral blood mononuclear cells (PBMC), we employed RNASeq analysis to compare the whole transcriptomic profile of a group of renal transplant recipients undergoing maintenance treatment with Everolimus (EVE) with those treated with Tacrolimus (TAC). Then, obtained results were validated by classical biomolecular methodologies. The statistical analysis allowed the identification of four genes discriminating the 2 study groups: Sushi Domain Containing 4 (SUSD4, P = 0.02), T Cell Leukemia/Lymphoma 1A (TCL1A, P = 0.02), adhesion G protein-coupled receptor E3 (ADGRE3, P = 0.01), Immunoglobulin Heavy Constant Gamma 3 (IGHG3, P = 0.03). All of them were significantly down-regulated in patients treated with EVE compared to TAC. The Area under Receiver Operating Characteristic (AUROC) of the final model based on these 4 genes was 73.1% demonstrating its good discriminative power. RT-PCR and ELISA validated transcriptomic results. Additionally, an in vitro model confirmed that EVE significantly down-regulates (P<0.001) TCL1A, SUSD4, ADGRE3 and IgHG3 in PBMCs as well as in T cells and monocytes isolated from healthy subjects. Taken together, our data, revealed, for the first time, a new four gene-based transcriptomic fingerprint down-regulated by EVE in PBMCs of renal transplant patients that could improve the available knowledge regarding some of the biological/cellular effects of the mTOR-Is (including their antineoplastic and immune-regulatory properties).

Intra-abdominal infections in solid organ transplant recipients: Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

This new guideline from the AST IDCOP reviews intra-abdominal infections (IAIs), which cause substantial morbidity and mortality among abdominal SOT recipients. Each transplant type carries unique risks for IAI, though peritonitis occurs in all abdominal transplant recipients. Biliary infections, bilomas, and intra-abdominal and intrahepatic abscesses are common after liver transplantation and are associated with the type of biliary anastomosis, the presence of vascular thrombosis or ischemia, and biliary leaks or strictures. IAIs after kidney transplantation include renal and perinephric abscesses and graft-site candidiasis, which is uncommon but may require allograft nephrectomy. Among pancreas transplant recipients, duodenal anastomotic leaks can have catastrophic consequences, and polymicrobial abscesses can lead to graft loss and death. Intestinal transplant recipients are at the highest risk for sepsis, infection due to multidrug-resistant organisms, and death from IAI, as the transplanted intestine is a contaminated, highly immunological, pathogen-rich organ. Source control and antibiotics are the cornerstone of the management of IAIs. Empiric antimicrobial regimens should be tailored to local susceptibility patterns and pathogens with which the patient is known to be colonized, with subsequent optimization once the results of cultures are reported.

Characteristics of community-acquired respiratory viruses infections except seasonal influenza in transplant recipients and non-transplant critically ill patients

Background/Purpose

Transplant recipients are vulnerable to life-threatening community-acquired respiratory viruses (CA-RVs) infection (CA-RVI). Even if non-transplant critically ill patients in intensive care unit (ICU) have serious CA-RVI, comparison between these groups remains unclear. We aimed to evaluate clinical characteristics and mortality of CA-RVI except seasonal influenza A/B in transplant recipients and non-transplant critically ill patients in ICU.

Methods

We collected 37,777 CA-RVs multiplex real-time reverse transcription-polymerase chain reaction test results of individuals aged ≥18 years from November 2012 to November 2017. The CA-RVs tests included adenovirus, coronavirus 229E/NL63/OC43, human bocavirus, human metapneumovirus, parainfluenza virus 1/2/3, rhinovirus, and respiratory syncytial virus A/B.

Results

We found 286 CA-RVI cases, including 85 solid organ transplantation recipients (G1), 61 hematopoietic stem cell transplantation recipients (G2), and 140 non-transplant critically ill patients in ICU (G3), excluding those with repeated isolation within 30 days. Adenovirus positive rate and infection cases were most prominent in G2 (p < 0.001). The median time interval between transplantation and CA-RVI was 30 and 20 months in G1 and G2, respectively. All-cause in-hospital mortality was significantly higher in G3 than in G1 or G2 (51.4% vs. 28.2% or 39.3%, p = 0.002, respectively). The mechanical ventilation (MV) was the independent risk factor associated with all-cause in-hospital mortality in all three groups (hazard ratio, 3.37, 95% confidence interval, 2.04–5.56, p < 0.001).

Conclusions

This study highlights the importance of CA-RVs diagnosis in transplant recipients even in long-term posttransplant period, and in non-transplant critically ill patients in ICU with MV.

Infections among pediatric transplant candidates: An approach to decision-making

INTRODUCTION

The presence of infections in the immediate pretransplant period poses challenges in decision-making. Delaying transplantation because of these infections may be required, but is associated with a risk to the potential recipient. The aim of this project was to develop a structured framework based on expert opinion to guide decision-making regarding the safety of transplantation for candidates with infection immediately before transplant, and to show how this framework can be applied to clinical scenarios.

METHODS

Categories were created as follows: Category A: no delay; Category B: brief delay (≤1 week); Category C: intermediate delay (>1 week); and Category D: more prolonged or indefinite delay. A survey containing 59 clinical scenarios was sent to members of the IPTA ID CARE committee. Answers were reviewed, and the level of agreement was characterized as follows: Level 1: ≥75% agreement; Level 2:51%-74% agreement; and Level 3: ≤50% agreement. 95% CIs were calculated for the mean overall agreement across 59 scenarios.

RESULTS

Among the panel, the agreement level ranged from 33% to 92% with the mean overall agreement across the 59 scenarios being 61%. For 7/59 scenarios, the lower bound of 95% CI was greater than 50%, indicating a difference at the 5% level of significance between the observed proportion and the chance level of 0.5.

SUMMARY

The document provides expert opinion regarding the need to delay transplantation in the setting of different infections. The most important points in the decision to proceed to SOT included the urgency of transplantation and the severity of infection.

Diagnostic and therapeutic approach to infectious diseases in solid organ transplant recipients

Purpose

Prognosis of solid organ transplant (SOT) recipients has improved, mainly because of better prevention of rejection by immunosuppressive therapies. However, SOT recipients are highly susceptible to conventional and opportunistic infections, which represent a major cause of morbidity, graft dysfunction and mortality.

Methods

Narrative review.

Results

We cover the current epidemiology and main aspects of infections in SOT recipients including risk factors such as postoperative risks and specific risks for different transplant recipients, key points on anti-infective prophylaxis as well as diagnostic and therapeutic approaches. We provide an up-to-date guide for management of the main syndromes that can be encountered in SOT recipients including acute respiratory failure, sepsis or septic shock, and central nervous system infections as well as bacterial infections with multidrug-resistant strains, invasive fungal diseases, viral infections and less common pathogens that may impact this patient population.

Conclusion

We provide state-of the art review of available knowledge of critically ill SOT patients with infections.

Evaluation of the impact of conventional immunosuppressant on the establishment of murine transplantation tolerance - an experimental study

Regulatory T cells (Tregs) play a significant role in immune tolerance. Since Treg function deeply depends on Interleukin-2 signaling, calcineurin inhibitors could affect their suppressive potentials, whereas mammalian target of rapamycin (mTOR) inhibitors may have less impact, as mTOR signaling is not fundamental to Treg proliferation. We previously reported a novel mixed hematopoietic chimerism induction regimen that promotes Treg proliferation by stimulating invariant natural killer T cells under CD40 blockade. Here, we use a mouse model to show the impact of tacrolimus (TAC) or everolimus (EVL) on the establishment of chimerism and Treg proliferation in the regimen. In the immunosuppressive drug-dosing phase, peripheral blood chimerism was comparably enhanced by both TAC and EVL. After dosing was discontinued, TAC-treated mice showed gradual graft rejection, whereas EVL-treated mice sustained long-term robust chimerism. Tregs of TAC-treated mice showed lower expression of both Ki67 and cytotoxic T lymphocyte antigen-4 (CTLA-4), and lower suppressive activity in vitro than those of EVL-treated mice, indicating that TAC negatively impacted the regimen by interfering with Treg proliferation and activation. Our results suggest that the usage of calcineurin inhibitors should be avoided if utilizing the regimen to induce Tregs in vivo for the establishment of mixed hematopoietic chimerism.

Prevention and Treatment of Yeast and Endemic Fungal Infections

Invasive fungal infections (IFIs) remain an important complication of solid organ transplantation owing to their significant morbidity and mortality and include infections due to Candida, Cryptococcus, endemic mycosis, and other rare yeasts and molds. IFIs occur in different intervals posttransplantation and depend on a number of extrinsic and intrinsic risk factors, some of which are specific to the type of organs transplanted, surgical techniques, and type of immunosuppressive medications. Donor-derived IFIs and emergence of new multidrug-resistant yeasts have been reported in various healthcare settings. Clinical manifestations of yeast and endemic fungal infections vary in different types of organ transplants. Diagnosis of IFIs in SOT recipients is challenging due to their nonspecific signs and symptoms owing to the impaired inflammatory responses as a result of immunosuppression and the lack of highly sensitive and specific diagnostic modalities. Early diagnosis is key to successful therapy, and physicians should have a high index of suspicion based on risk factors and epidemiology of these pathogens. Antifungal treatment strategies for yeast infections have been outlined in various society guidelines. Management of complications that arise before or during antifungal therapy is critical for optimizing clinical response.

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.

Infections in Heart and Lung Transplant Recipients

Infections in heart and lung transplant recipients are complex and heterogeneous. This article reviews the epidemiology, risk factors, specific clinical syndromes, and most frequent opportunistic infections in heart and/or lung transplant recipients that will be encountered in the intensive care unit and will provide a practical approach of empirical management.

In-hospital outcomes for solid organ transplants according to type 2 diabetes status: An observational, 15-year study in Spain

AIMS

To describe trends and outcomes during admission for solid organ transplant in people with or without type 2 diabetes in Spain, 2001-2015.

METHODS

We used national hospital discharge data to select all hospital admissions for kidney, lung, heart, and liver transplant. We estimated admission rates stratified by type 2 diabetes status. We built Poisson regression models to compare the adjusted time trends in admission rates. We tested in-hospital mortality (IHM) in logistic regression analyses.

RESULTS

We identified 50 964 transplants (16.7% in people with type 2 diabetes): kidney, 30 919; lung, 2810; heart, 3649; liver, 13 586. The overall adjusted incidence rate ratios (95% confidence intervals) of admission in people with type 2 diabetes vs no diabetes were 2.4 (2.32-2.48) for kidney, 1.51 (1.33-1.70) for lung, 2.87 (2.63-3.13) for heart, and 4.16 (3.99-4.33) for liver transplant. In the multivariate analysis, IHM decreased significantly over time for all types of transplant. Type 2 diabetes independently predicted lower IHM during admission only for heart (Odds ratio, OR [95% CI] = 0.62 [0.47-0.81]) and liver transplant (OR [95% CI] = 0.69 [0.58-0.82]).

CONCLUSIONS

Admission rates for solid organ transplant were higher in people with type 2 diabetes than in people without diabetes. Type 2 diabetes was associated with lower in-hospital mortality during admission for heart and liver transplant.

Approach to Transplant Infectious Diseases in the Emergency Department

The emergency department (ED) is an increasingly important site of care for patients who have undergone solid organ transplantation or hematopoietic cell transplantation. It is paramount for emergency physicians to recognize infections early on, obtain appropriate diagnostic testing, initiate empirical antimicrobial therapy, and consider specialty consultation and inpatient admission when caring for these patients. This review provides emergency physicians with an approach to the assessment of transplant patients' underlying risk for infection, formulation of a broad differential diagnosis, and initial management of transplant infectious disease emergencies in the ED.

Severe infections in critically ill solid organ transplant recipients

BACKGROUND

Severe infections are among the most common causes of death in immunocompromised patients admitted to the intensive care unit. The epidemiology, diagnosis and treatment of these infections has evolved in the last decade.

AIMS

We aim to provide a comprehensive review of these severe infections in this population.

SOURCES

Review of the literature pertaining to severe infections in critically ill solid organ transplant recipients. PubMed and Embase databases were searched for documents published since database inception until November 2017.

CONTENT

The epidemiology of severe infections has changed in the immunocompromised patients. This population is presenting to the intensive care unit with specific transplantation procedure-related infections, device-associated infections, a multitude of opportunistic viral infections, an increasing number of nosocomial infections and bacterial diseases with a more limited therapeutic armamentarium. Both molecular diagnostics and imaging techniques have had substantial progress in the last decade, which will, we hope, translate into faster and more precise diagnoses, as well as more optimal empirical treatment de-escalation.

IMPLICATIONS

The key clinical elements to improve the outcome of critically ill solid organ transplant recipients depend on the knowledge of geographic epidemiology, specific surgical procedures, net state of immunosuppression, hospital microbial ecology, aggressive diagnostic strategy and search for source control, rapid initiation of antimicrobials and minimization of iatrogenic immunosuppression.

Diagnostic delay and mortality of active tuberculosis in patients after kidney transplantation in a tertiary care hospital in China

TB infection in patients after kidney transplantation remains a concern in a successful long-term outcome. This retrospective, descriptive study was performed on tuberculosis infection after kidney transplantation in the Department of Infectious Disease of the First Affiliated Hospital of Zhejiang University, a tertiary care hospital in China, from January 2011 to April 2017, with the aim to explain the clinical features of active tuberculosis after kidney transplantation and explore the correlated factors for diagnostic delay and mortality. It included 48 cases. All these cases were followed up for at least 12 months after anti-tuberculosis therapy, except the ones who died during this period. The median time of transplantation to active tuberculosis of these 48 patients was about 5.4 years. The time from a first hospital visit to the diagnosis (diagnostic delay) of 12 (25%) cases was more than 30 days. The correlated factors for the diagnostic delay more than 30 days were a fever for more than 2 weeks and antibiotic use for more than 2 weeks. Nine (18.8%) cases died during the anti-tuberculosis therapy or following-up period due to TB relapse. The risk factors for mortality were severe complications, such as encephaledema, severe pneumonia, intestinal perforation, liver function failure, and the following multiple-organ failure. In conclusion, the possibility of tuberculosis infection should be carefully assessed and sometimes diagnostic anti-tuberculosis therapy may be required for patients who had a fever for more than 2 weeks or used antibiotics for more than 2 weeks after kidney transplantation. Severe complications and the following multiple-organ failure might increase the mortality among these patients.

Dysfunctional immunoregulation in human liver allograft rejection associated with compromised galectin-1/CD7 pathway function

Regulatory T cells in rejected allograft patients display an inability to control responder T cells. Galectin-1 (Gal1) inhibits responder T cells through binding CD7. We investigated whether the dysfunctional immunoregulation in liver allograft rejection patients results from reduced regulatory T-cell Gal1 expression and/or responder T-cell CD7 expression. Circulating regulatory T cells and responder T cells were profiled from 31 acute rejection transplant patients, 85 transplant patients in remission, and 40 healthy controls. CD7+ and CD7− responder T cells were co-cultured with regulatory T cells to assess regulatory T-cell suppressor function. Gal1-small interfering RNA was used to silence regulatory T-cell Gal1. The CD7+ cell percentage was inversely correlated with AST, ALT, and GGT levels. The proportions of CD7+ responder T cells and Gal1+ regulatory T cells were higher in healthy controls than in transplant patients in remission and lowest in acute rejection transplant patients. Notably, CD7+ responder T-cell susceptibility to Gal1+ regulatory T-cell control was ranked in the same manner. Silencing Gal1 expression in regulatory T cells reduced their ability to suppress CD7+ (but not CD7−) responder T cells. Additionally, the proportions of CD43+ and CD45+ responder T cells were higher in healthy controls than in acute rejection transplant patients. CD43 co-expression (but not CD45 co-expression) on CD7+ responder T cells promoted their apoptosis in a Gal1-dependent manner. In sum, dysfunctional immunoregulation in liver allograft rejection patients can be partly attributed to reduced regulatory T-cell Gal1 expression and reduced responder T-cell CD7 expression. Responder T-cell CD43 downregulation in acute rejection patients may further contribute to reduced responder T-cell responsiveness to regulatory T-cell control.

Cytomegalovirus and Other β-Herpesviruses

Cytomegalovirus (CMV), human herpes virus (HHV)-6, and HHV-7 are ubiquitous β-herpesviruses that can cause opportunistic infection and disease in kidney transplant recipients. Active CMV infection and disease are associated with acute allograft failure and death, and HHV-6 and HHV-7 replication are associated with CMV disease. CMV prevention strategies are used commonly after kidney transplantation, and include prophylaxis with antiviral medications and preemptive treatment upon the detection of asymptomatic viral replication in blood. Both approaches decrease CMV disease and allograft rejection, but CMV prophylaxis is preferred for high-risk patients because it is easy to administer and may be more effective in real-world settings. CMV disease commonly occurs even with current preventive strategies, whereas HHV-6 and HHV-7 diseases are rare. The clinical manifestations of CMV, HHV-6, and HHV-7 are nonspecific, and laboratory confirmation is essential to establishing diagnoses. Although nucleic acid testing has supplanted other diagnostic modalities given its high sensitivity and specificity, histopathologic examination sometimes is necessary to identify disease definitively. Ganciclovir and valganciclovir are the treatments of choice for CMV and HHV-6, and foscarnet can be used to treat HHV-7. Treatment duration should be informed by the initial severity of disease, and subsequent clinical and virologic responses.

Risk factors for development of surgical site infections among liver transplantation recipients: An integrative literature review

BACKGROUND

Surgical site infection (SSI) is an important complication in the postoperative period of recipients of liver transplantation. The purpose of this integrative literature review is to summarize the knowledge available about the risk factors contributing to the development SSI among adults undergoing liver transplantation.

METHODS

We reviewed the Medical Literature Analysis and Retrieval System Online/PubMed, the Cumulative Index to Nursing and Allied Health Literature, the Latin American and Caribbean Health Sciences Literature, Scopus, and Web of Science databases.

RESULTS

Two hundred sixteen articles were identified and the final sample of 9 articles was analyzed in full length. The SSI rate found in the investigations ranged between 9.6% and 35.5%. Risk factors for SSI were grouped into categories related to the preoperative period, such as Model for End-Stage Renal Disease score > 35 and ventilated support on day of transplant; to the intraoperative period activity, such as transfusion of packed red blood cells, extended surgical time, hyperglycemia >200 mg/dL, use of vasopressor drugs, and ascites flow >1 L; and to the donor/recipient relationship, such as age differences >10 years, ratio of donor liver mass to recipient body mass < 0.01. Additionally, centers that annually perform <50 transplants appear to have higher rates of SSI.

CONCLUSIONS

Few studies have addressed the subject of SSI in relation to liver transplantation in the scientific literature. Risk factors for SSI in patients who underwent liver transplantation vary between institutions.