The adaptive and innate immune systems coordinate for successful control of CMV infection.

Previous studies of the immune control of cytomegalovirus infection have primarily focused on analysis of the traditional adaptive T-cell response. Donadeu et al. bring a new perspective through evaluation of multiple adaptive and innate immune subtypes in parallel with cytomegalovirus-specific cell-mediated immunity in a prospective cohort of kidney transplant recipients with findings validated in 2 independent studies. Identification of a natural killer T-cell subtype associated with cell-mediated immunity and freedom from cytomegalovirus infection demonstrates the importance of the coordinated innate and adaptive immune response for effective viral control.

Domestically Acquired NDM-1-Producing Pseudomonas aeruginosa, Southern California, USA, 2023.

We describe a case of New Delhi metallo-ß-lactamase 1-producing carbapenem-resistant Pseudomonas aeruginosa (CRPA) in a transplant patient with multiple hospitalizations in California, USA. Whole-genome sequencing revealed the isolate was genetically distinctive, despite ≈95% similarity to other global strains. The patient's lack of international travel suggests this CRPA was acquired domestically.

Cowpox to COVID: History of vaccination in the immunocompromised host.

BACKGROUND: The use of vaccination to prevent infection has a long history, starting in the 1700s with Jenner. New innovations have led to improvements in the safety and efficacy of vaccines, from live attenuated viruses to subunit vaccines, to RNA-based vaccination for SARS-CoV-2. Despite this progress, however, solid organ transplant (SOT) recipients on immunosuppression demonstrate an impaired vaccine response compared with healthy controls. This issue is important given the increased vulnerability to infection in immunocompromised patients, especially in the setting of the Coronavirus Disease 2019 (COVID-19) pandemic. METHODS: We reviewed the literature on key topics in vaccination with significant clinical impact on SOT patients. RESULTS: Prior to COVID-19, a large amount of data has been published demonstrating impaired humoral and T-cell responses to multiple vaccinations targeting influenza, hepatitis B, VZV, and Pneumococcus. Poor immunogenicity can be addressed through the use of adjuvants to boost the immune response, even in the setting of senescence related to age or immunosuppression. New vaccines provide hope for preventing infection due to hepatitis C and Cytomegalovirus, and to the emerging infection, monkeypox. The data on the impact of the COVID-19 vaccine in SOT patients is reviewed, with a focus on seroconversion, antibody titer, and antigen-specific T cells. Factors associated with impaired response, including mycophenolate, are described. CONCLUSION: The history of vaccination demonstrates how scientific breakthroughs can be applied to clinical challenges. New approaches using adjuvants, strategic antigen selection, and RNA-based vaccines offer the potential to improve immune response in SOT recipients. Future innovations are needed to better protect the vulnerable immunocompromised host.

Donor call simulation: A novel medical education tool to evaluate trainees' clinical decision-making in transplant infectious disease.

BACKGROUND: Evaluating organ suitability for transplantation based on infection risk is a core competency in transplant infectious disease (TID). It is unclear if trainees have opportunities to practice during training. We created a simulation curriculum to develop and evaluate this skill among infectious disease (ID) trainees. METHODS: We created six simulation questions about organ suitability for transplant based on infection risk. During trainees' TID rotations, faculty texted or paged the simulation cases posing as the transplant coordinator. Trainees had 15 min to ask questions before deciding the suitability of the organ and explained their clinical reasoning in a survey. Trainees completed a post-simulation survey to evaluate its effectiveness. RESULTS: ID trainees, including residents and fellows on rotation, from seven centers participated. Eighty-seven percent (13/15) of trainees felt the simulation was effective in teaching them this concept, and 80% (12/15) felt prepared for clinical practice. The proportion of correct responses was generally high among the six different cases (43%-100%); correct responses increased for some cases in the post-activity survey. Of the 100 clinical reasoning decisions made during the activity, 19% were discordant, where the trainee correctly identified suitable organs for incorrect reasons. CONCLUSION: Our simulation was effective in teaching when to accept or reject an organ for transplant and was a valuable educational tool. By evaluating clinical reasoning for decisions our simulation provides educators with nuanced insight and allows for targeted coaching. This study demonstrates a critical need for further educational tools in TID.

Plasma CXCL9 and CXCL10 at allograft injury predict chronic lung allograft dysfunction.

Histopathologic lung allograft injuries are putative harbingers for chronic lung allograft dysfunction (CLAD). However, the mechanisms responsible are not well understood. CXCL9 and CXCL10 are potent chemoattractants of mononuclear cells and potential propagators of allograft injury. We hypothesized that these chemokines would be quantifiable in plasma, and would associate with subsequent CLAD development. In this prospective multicenter study, we evaluated 721 plasma samples for CXCL9/CXCL10 levels from 184 participants at the time of transbronchial biopsies during their first-year post-transplantation. We determined the association between plasma chemokines, histopathologic injury, and CLAD risk using Cox proportional hazards models. We also evaluated CXCL9/CXCL10 levels in bronchoalveolar lavage (BAL) fluid and compared plasma to BAL with respect to CLAD risk. Plasma CXCL9/CXCL10 levels were elevated during the injury patterns associated with CLAD, acute rejection, and acute lung injury, with a dose-response relationship between chemokine levels and CLAD risk. Importantly, there were strong interactions between injury and plasma CXCL9/CXCL10, where histopathologic injury associated with CLAD only in the presence of elevated plasma chemokines. We observed similar associations and interactions with BAL CXCL9/CXCL10 levels. Elevated plasma CXCL9/CXCL10 during allograft injury may contribute to CLAD pathogenesis and has potential as a minimally invasive immune monitoring biomarker.

Enteral feeding tube administration with therapeutic drug monitoring of crushed posaconazole tablets and opened isavuconazonium sulfate capsules.

BACKGROUND: Isavuconazole and posaconazole are commonly used for both prophylaxis and treatment of invasive fungal infections. These agents are formulated for oral administration as a capsule and delayed release (DR) tablet or suspension, respectively. In patients unable to swallow, alternative means of administration, such as crushing posaconazole DR tablets and opening isavuconazole capsules, may be used to avoid IV administration or use of posaconazole suspension, which often produces subtherapeutic concentrations. OBJECTIVES: To assess the feasibility of achieving target plasma drug concentrations with enteral feeding tube (EFT) administration of crushed posaconazole DR tablets and opened isavuconazole capsules. METHODS: We retrospectively reviewed pharmacy records to identify patients receiving EFT administration of posaconazole or isavuconazole with concurrent therapeutic drug monitoring from October 2019 to June 2021. Plasma concentrations of either agent as well as clinical outcomes were documented. RESULTS: We identified 37 patients receiving 38 courses of EFT isavuconazole or posaconazole. The majority of patients received primary prophylaxis following lung transplantation (64.9%). Plasma concentrations upon first assessment were therapeutic in the majority of patients (posaconazole 71.5%, isavuconazole 83.3%) with a mean level of 1.61 ± 0.77 mg/L for posaconazole and 2.07 ± 1.1 mg/L for isavuconazole. Of those that were subtherapeutic on initial assessment, all but one subsequently achieved target levels upon dose titration. Standard maintenance doses were used in all isavuconazole and most posaconazole patients. CONCLUSIONS: Our case series demonstrates that isavuconazole and posaconazole can be administered via EFT with concurrent therapeutic drug monitoring to achieve target plasma concentrations in the majority of patients.

Predictive value of chart-based frailty evaluation for lung transplant candidates.

Frailty, defined as a state of decreased physiologic reserve, has been correlated with poorer outcomes after hospitalization or surgery. Studies in lung transplant patients have associated frailty with an increased risk of post-transplant mortality; however, a unified approach is lacking. The identification of frail patients can help clinicians pre-emptively target modifiable risk factors and may facilitate risk stratification. The Frailty Risk Score (FRS) is a chart review-based approach based on eight symptoms and four laboratory biomarkers. We applied this method in a retrospective study to investigate its utility in predicting post-transplant lung outcomes. Eighty-four lung transplant recipients were evaluated, including 51 older (≥ 60) and 33 younger (< 60) patients. Median FRS score was 3.9, with 63 categorized as frail (75%) and 21 as non-frail (25%), using a previously published cut-off of ≥3 to define frailty. A high FRS was associated with readmission in the first year after transplantation and with the number of readmissions. There was also an association between FRS score and death (p = .047). FRS may be a viable tool in the assessment of lung transplant candidates. Frail patients may benefit from earlier referral and targeted therapy prior to transplant, as well as close post-transplant follow-up.

Benefits of both physical assessment and electronic health record review to assess frailty prior to heart transplant.

INTRODUCTION: Frailty status affects outcomes after heart transplantation, but the optimal way to assess frailty prior to transplant remains unknown. METHODS: This single-center, observational study assessed 44 heart transplant candidates for frailty using three methods. The Short Physical Performance Battery (SPPB) and Fried Frailty Phenotype (FFP) were used as two physical assessments of frailty. The Frailty Risk Score (FRS) was used as a chart-review based assessment measuring 20 different biopsychosocial and functional components, including biomarkers, depression, cognitive impairment, and sleep. RESULTS: We determined the correlation between FRS, SPPB, and FFP and how each correlated with clinical outcomes. Of 44 participants, mean age was 60 years. FRS correlated with SPPB and FFP (P = .043, P < .001, respectively). Higher frailty as measured by SPPB and FRS was significantly associated with lack of achieving waitlist status (P = .022; P = .002) and not being transplanted (P = .026; P = .008). Higher frailty by SPPB and FFP was also associated with mortality (P = .010; P = .025). CONCLUSION: SPPB and chart-review FRS showed potential for predicting waitlist and transplant status of heart transplant candidates, while SPPB and FFP were associated with mortality. Additional studies may serve to validate these observations.

Impact of solid organ transplant status on outcomes of hospitalized patients with COVID-19 infection.

BACKGROUND: The COVID-19 pandemic has caused significant morbidity and mortality in solid organ transplant (SOT) recipients. However, it remains unclear whether the risk factor for SOT patients is the immunosuppression inherent to transplantation versus patient comorbidities. METHODS: We reviewed outcomes in a cohort of SOT (n = 129) and non-SOT (NSOT) patients (n = 708) admitted to the University of California, Los Angeles for COVID-19 infection. Data analyses utilized multivariate logistic regression to evaluate the impact of patient demographics, comorbidities, and transplant status on outcomes. SOT patients were analyzed by kidney SOT (KSOT) versus nonkidney SOT (NKSOT) groups. RESULTS: SOT and NSOT patients with COVID-19 infection differed in terms of patient age, ethnicity, and comorbidities. NKSOT patients were the most likely to experience death, with a mortality rate of 16.2% compared with 1.8% for KSOT and 8.3% for NSOT patients (p = .013). Multivariable analysis of hospitalized patients revealed that patient age (odds ratio [OR] 2.79, p = .001) and neurologic condition (OR 2.66, p < .001) were significantly associated with mortality. Analysis of ICU patients revealed a 2.98-fold increased odds of death in NKSOT compared with NSOT patients (p = .013). CONCLUSIONS: This study demonstrates the importance of transplant status in predicting adverse clinical outcomes in patients hospitalized or admitted to the ICU with COVID-19, especially for NKSOT patients. Transplant status and comorbidities, including age, could be used to risk stratify patients with COVID-19. This data suggests that immunosuppression contributes to COVID-19 disease severity and mortality and may have implications for managing immunosuppression, especially for critically ill patients admitted to the ICU.

Mycoplasma hominis infections in solid organ transplant recipients: Clinical characteristics, treatment outcomes, and comparison of phenotypic and genotypic susceptibility profiles.

BACKGROUND: Mycoplasma hominis can cause significant infections after solid organ transplantation (SOT). Treatment should be guided by susceptibility testing, but conventional lab methods are laborious with prolonged turnaround time (TAT). This case series compares the phenotypic and genotypic susceptibility profiles of M. hominis isolates identified from SOT patients. METHODS: This is a single-center retrospective study evaluating SOT recipients with confirmed M. hominis infections. Patients' demographic, clinical, microbiological, and radiographic data were collected. Culture of M. hominis isolates was performed according to current Clinical and Laboratory Standards Institute guidelines. Phenotypic susceptibility testing was performed by University of Alabama Diagnostic Mycoplasma Laboratory. Whole genome sequencing (WGS) was performed followed by bioinformatic analysis of known genetic determinants of resistance. RESULTS: Seven SOT recipients with M. hominis infections were identified. Two out of seven (28.5%) patients had resistance detected by phenotypic susceptibility testing (Case 5 to levofloxacin and Case 7 to tetracycline). Genomic analyses confirmed the presence of mutations in the parC and parE topoisomerase genes at positions conferring to fluoroquinolone resistance in the isolate from Case 5, while the tetracycline-resistant isolate from Case 7 harbored the tetM gene. The median TAT from the date of specimen collection was 24 days for phenotypic susceptibility testing and 14 days for genotypic susceptibility testing. All seven patients received antimicrobials directed toward M. hominis and recovered with complete resolution of infection. CONCLUSIONS: WGS may offer a novel and more rapid methodology for M. hominis susceptibility testing to help optimize antimicrobial usage, but more data are needed.

Frailty and aging-associated syndromes in lung transplant candidates and recipients.

Many lung transplant candidates and recipients are older and frailer compared to previous eras. Older patients are at increased risk for pre- and posttransplant mortality, but this risk is not explained by numerical age alone. This manuscript represents the product of the American Society of Transplantation (AST) conference on frailty. Experts in the field reviewed the latest published research on assessment of elderly and frail lung transplant candidates. Physical frailty, often defined as slowness, weakness, low physical activity, shrinking, and exhaustion, and frailty evaluation is an important tool for evaluation of age-associated dysfunction. Another approach is assessment by cumulative deficits, and both types of frailty are common in lung transplant candidates. Frailty is associated with death or delisting before transplant, and may be associated with posttransplant mortality. Sarcopenia, cognitive dysfunction, depression, and nutrition are other important components for patient evaluation. Aging-associated inflammation, telomere dysfunction, and adaptive immune system senescence may also contribute to frailty. Developing tools for frailty assessment and interventions holds promise for improving patient outcomes before and after lung transplantation.

Leukocyte transcriptome indicators of development of infection in kidney transplant recipients.

After kidney transplantation, infection and death are important clinical complications, especially for the growing numbers of older patients with limited resilience to withstand adverse events. Evaluation of changes in gene expression in immune cells can reveal the underlying mechanisms behind vulnerability to infection. A cohort of 60 kidney transplant recipients was evaluated. Gene expression in peripheral blood mononuclear cells 3 months after kidney transplantation was analyzed to compare differences between patients with infection and those who were infection-free in the first-year post-transplant. Pro-inflammatory genes such as IL1B, CCL4, and TNF were found to be downregulated in post-transplant PBMC from patients who developed infection. In contrast, genes involved in metabolism, HLA genes, and transcripts involved in type I interferon innate antiviral responses were found to be upregulated. Promoter-based bioinformatic analyses implicated increased activity of interferon regulatory factors, erythroid nuclear factor (E2), and CCAAT-enhancer-binding protein (C/EBP) in patients who developed infections. Differential patterns of gene expression were observed in patients who developed infection after kidney transplantation, with patterns distinct from changes associated with patient age, suggesting possible mechanisms behind vulnerability to infection. Assessment of gene expression in blood may offer an approach for patient risk stratification and monitoring after transplantation.

Early cytomegalovirus DNAemia and antiviral dose adjustment in high vs intermediate risk kidney transplant recipients.

BACKGROUND: Cytomegalovirus (CMV) infection continues to negatively affect outcomes for solid organ transplant recipients, despite the advent of strategies for preemptive surveillance and prophylaxis. The impact is especially great for CMV seronegative recipients of donor seropositive organs, who typically lack the ability to control CMV infection at the time of transplantation. METHODS: We reviewed episodes of CMV DNAemia in a modern cohort of kidney transplant recipients over a 3-year period at a high-volume transplant center to investigate the frequency of DNAemia during antiviral prophylaxis. RESULTS: Despite receipt of antiviral prophylaxis per current guidelines, 75 cases of CMV DNAemia were observed in the first 100 days after transplantation. For high risk patients, median time to DNAemia was 75 days after transplantation, and the majority of patients had experienced dose-reduction of valganciclovir due to renal insufficiency. Review of CMV seropositive intermediate risk patients demonstrated DNAemia occurring earlier after transplantation compared with high risk patients with a median time of 64 days (P = .029). The impact of valganciclovir dose adjustment was less notable in the intermediate risk group. CONCLUSIONS: Guidelines recommend beginning routine surveillance for CMV after the completion of antiviral prophylaxis. Our findings suggest that closer monitoring may be beneficial, especially for high risk patients at risk for DNAemia. Patients requiring dose adjustment of valganciclovir due to renal insufficiency may be at increased risk for CMV DNAemia. Improved methods for CMV prophylaxis and evaluation of immunologic risk for CMV DNAemia and disease are needed to improve patient outcomes after kidney transplantation.

Frailty Does Not Impact Caregiver Burden in Patients with Cirrhosis.

BACKGROUND: Frailty is common and is associated with increased mortality, lower quality of life, and higher readmission rates in cirrhotic patients. Not only are these outcomes important, but further understanding the impact of frailty on a caregiver's life is crucial to better comprehend caregiver burden in cirrhotic patients and develop strategies to improve care for patients and their caregivers. METHODS: A single-center, prospective study was conducted of cirrhotic patients and their caregivers between 4/1/2019 and 11/1/2019. Frailty testing combined aspects from the Fried Frailty Instrument, Short Physical Performance Battery, and activities of daily living. Caregivers completed questionnaires to evaluate caregiver burden using the Zarit Burden Interview (ZBI-12), and perceived social support, using the Interpersonal Support Evaluation List. RESULTS: In total, 94 cirrhotic patients were included, 50% males with a median age of 63.1 years. The most common etiology of cirrhosis was nonalcoholic steatohepatitis. Frailty was prevalent (45.1%). In total, 12.8% of caregivers reported a high burden based on ZBI-12. There was no association between frailty and caregiver burden, hospitalization rates, or death. However, frailty was associated with a higher number of outpatient GI visits (p = 0.002). Lower perceived social support among caregivers was associated with a higher caregiver burden (p < 0.0001). CONCLUSION: Frailty is prevalent in cirrhotic patients but is not associated with higher rates of caregiver burden. Low perceived social support among caregivers, however, was associated with higher caregiver burden. It is important to recognize the impact of caregiver burden on caregivers of cirrhotic patients and ensure caregivers have the appropriate support to mitigate burden.

Coinfections of Two Strains of NDM-1- and OXA-232-Coproducing Klebsiella pneumoniae in a Kidney Transplant Patient.

We report here a fatal case of carbapenem-resistant Klebsiella pneumoniae (CRKP) infections in a renal transplant patient without a travel history in the prior year, from whom 2 genetically different CRKP (sequence type 14 [ST14] and ST2497) strains carrying the same plasmids and antimicrobial resistance genes, including blaNDM-1, blaOXA-232, blaCTX-M-15, armA, and tet(D), were isolated from blood and the abdominal cavity. The isolates were susceptible to colistin, tigecycline, eravacycline, and cefiderocol, which was used to treat the CRKP in combination with ceftazidime-avibactam and polymyxin B and resulted in bacterial clearance. Despite the aggressive treatment, the patient died of ischemic colitis and multiorgan failure.

Heart transplantation in the early phase of the COVID-19 pandemic: A single-center case series.

The infectious disease coronavirus disease 2019 (COVID-19) was declared a pandemic by the World Health Organization in March 2020. The impact of COVID-19 on solid organ transplantations, including heart transplantation, is currently unclear. Many transplant programs have been forced to swiftly re-evaluate and adapt their practices, leading to a marked decrease in transplants performed. This trend has been due to various factors, including increased donor COVID-19 screening scrutiny and recipient waiting list management in anticipation of COVID-19 critical care surge capacity planning. In the face of these unknown variables, determining when and how to proceed with transplantation in our population of patients with end-stage cardiomyopathies is challenging. Here, we describe our center's experience with orthotopic heart transplantation (OHT) in one of the country's pandemic epicenters, where we performed eight OHTs in the first 2 months after community spread began in late February 2020.

The aging transplant population and immunobiology: any therapeutic implication?

PURPOSE OF REVIEW: The aim of this review is to describe the latest investigations into the immunobiology of aging and the potential impact on outcomes after mechanical circulatory support implantation and heart transplantation. This information is relevant given the growing numbers of older patients with heart failure undergoing evaluation for mechanical circulatory support device (MCSD) or heart transplantation. RECENT FINDINGS: A host of aging-associated aspects of immune dysfunction have been described in the general population including T-cell senescence, exhaustion, and terminal dedifferentiation, as well as impaired function of innate immune cells. Another important consequence of T-cell senescence is inflammation, which is known to have a strong relationship with both heart failure and frailty in older patients. Recent data on the association between T-cell and monocyte phenotypes as well as evaluation of gene expression and adverse outcomes after MCSD suggests the potential value of immunologic assessment of MCSD and heart transplant candidates and recipients. Measurement of physical frailty represents another avenue for patient evaluation that may complement immunologic assessment. Determination of immune dysfunction and frailty prior to transplantation may have implications for choice of induction and dosing of maintenance immunosuppression. SUMMARY: As the age of transplant and MCSD candidates and recipients continues to increase, it is important for providers to recognize the potential impact of aging-associated immune dysfunction and how it may influence candidate selection, postintervention monitoring, and adjustment of immunosuppression.

Report from the American Society of Transplantation on frailty in solid organ transplantation.

A consensus conference on frailty in kidney, liver, heart, and lung transplantation sponsored by the American Society of Transplantation (AST) and endorsed by the American Society of Nephrology (ASN), the American Society of Transplant Surgeons (ASTS), and the Canadian Society of Transplantation (CST) took place on February 11, 2018 in Phoenix, Arizona. Input from the transplant community through scheduled conference calls enabled wide discussion of current concepts in frailty, exploration of best practices for frailty risk assessment of transplant candidates and for management after transplant, and development of ideas for future research. A current understanding of frailty was compiled by each of the solid organ groups and is presented in this paper. Frailty is a common entity in patients with end-stage organ disease who are awaiting organ transplantation, and affects mortality on the waitlist and in the posttransplant period. The optimal methods by which frailty should be measured in each organ group are yet to be determined, but studies are underway. Interventions to reverse frailty vary among organ groups and appear promising. This conference achieved its intent to highlight the importance of frailty in organ transplantation and to plant the seeds for further discussion and research in this field.

Adenovirus in solid organ transplant recipients: Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice.

These updated guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the diagnosis, prevention, and management of adenovirus infections after solid organ transplantation. Adenovirus is an important cause of infectious complications in both stem cell transplant and SOT patients, causing a range of clinical syndromes including pneumonitis, colitis, and disseminated disease. The current update of the guidelines highlights that adenovirus surveillance testing should not be performed in asymptomatic recipients. Serial quantitative PCR might play a role in the decision to initiate or assess response to therapy in a symptomatic patient. The initial and most important components of therapy remain supportive care and decrease in immunosuppression. The use of antiviral therapy is not supported by prospective randomized clinical trials. However, intravenous cidofovir is considered the standard practice for treatment of severe, progressive, or disseminated adenovirus disease in most transplant centers. Intravenous immunoglobulin may be beneficial, primarily in a select group of patients with hypogammaglobulinemia. Future approaches to treatment of adenovirus disease may include administration of adenovirus-specific T-cell therapy.

Screening of donors and recipients for infections prior to solid organ transplantation.

PURPOSE OF REVIEW: This review is a brief overview of current guidelines on screening donors and candidates for bacterial, fungal, parasitic and viral infections prior to solid organ transplantation. The pretransplant period is an important time to evaluate infection exposure risk based on social history as well as to offer vaccinations. RECENT FINDINGS: One of the major changes in the past few years has been increased utilization of increased Public Health Service risk, HIV positive, and hepatitis C-positive donors. There has also been increased attention to donor and recipient risks for geographically associated infections, such as endemic fungal infections and flaviviruses. SUMMARY: Screening for donors and candidates prior to organ transplantation can identify and address infection risks. Diagnosing infections in a timely manner can help guide treatment and additional testing. Use of necessary prophylactic treatment in organ recipients can prevent reactivation of latent infections and improve posttransplant outcomes.