Donor-derived infections in solid organ transplant recipients

Modulatory immune responses in fungal infection associated with organ transplant - advancements, management, and challenges

Organ transplantation stands as a pivotal achievement in modern medicine, offering hope to individuals with end-stage organ diseases. Advancements in immunology led to improved organ transplant survival through the development of immunosuppressants, but this heightened susceptibility to fungal infections with nonspecific symptoms in recipients. This review aims to establish an intricate balance between immune responses and fungal infections in organ transplant recipients. It explores the fundamental immune mechanisms, recent advances in immune response dynamics, and strategies for immune modulation, encompassing responses to fungal infections, immunomodulatory approaches, diagnostics, treatment challenges, and management. Early diagnosis of fungal infections in transplant patients is emphasized with the understanding that innate immune responses could potentially reduce immunosuppression and promise efficient and safe immuno-modulating treatments. Advances in fungal research and genetic influences on immune-fungal interactions are underscored, as well as the potential of single-cell technologies integrated with machine learning for biomarker discovery. This review provides a snapshot of the complex interplay between immune responses and fungal infections in organ transplantation and underscores key research directions.

Infection and clinical xenotransplantation: Guidance from the Infectious Disease Community of Practice of the American Society of Transplantation

This guidance was developed to summarize current approaches to the potential transmission of swine-derived organisms to xenograft recipients, health care providers, or the public in clinical xenotransplantation. Limited specific data are available on the zoonotic potential of pig pathogens. It is anticipated that the risk of zoonotic infection in xenograft recipients will be determined by organisms present in source animals and relate to the nature and intensity of the immunosuppression used to maintain xenograft function. Based on experience in allotransplantation and with preclinical models, viral infections are of greatest concern, including porcine cytomegalovirus, porcine lymphotropic herpesvirus, and porcine endogenous retroviruses. Sensitive and specific microbiological assays are required for routine microbiological surveillance of source animals and xenograft recipients. Archiving of blood samples from recipients, contacts, and hospital staff may provide a basis for microbiological investigations if infectious syndromes develop. Carefully implemented infection control practices are required to prevent zoonotic pathogen exposures by clinical care providers. Informed consent practices for recipients and their close contacts must convey the lack of specific data for infectious risk assessment. Available data suggest that infectious risks of xenotransplantation are manageable and that clinical trials can advance with carefully developed protocols for pretransplant assessment, syndrome evaluation, and microbiological monitoring.

The relationship between chikungunya virus and the kidneys: A scoping review

Several atypical forms of chikungunya fever (CHIK) have been described, including neurological, cardiac and renal involvement. These forms may be related to high morbidity and mortality rates. This scoping review based on the PubMed, Scopus, and WOS databases aims to identify and summarise all the available evidence regarding the clinical and histopathological presentations and risk factors associated with kidney injury related to CHIK, as well as the clinical impact. Thus, a total of 54 papers were selected from 1606 initial references after applying the defined inclusion criteria. Data on the association between kidney injury and CHIK are scarce, with studies only conducted in the acute phase of the disease, lacking further characterisation. Kidney injury incidence in hospitalised patients using the Kidney Disease Improving Global Outcomes criteria varies from 21% to 45%, being higher among patients with atypical and severe manifestations. Although acute kidney injury does not seem to be related to viraemia, it may be related to higher mortality. Few studies have described the renal histopathological changes in the acute phase of CHIK, with prevalent findings of acute interstitial nephritis with mononuclear infiltrate, glomerular congestion and nephrosclerosis. Only one study assessed the kidney function of patients in the subacute and chronic phases of CHIK. Additionally, individuals with comorbidities, including chronic kidney disease, may be among those with a greater risk of presenting worse outcomes when affected by CHIK. The results described herein may contribute to better understand the relationship between the kidneys and chikungunya virus.

Epidemiology of Invasive Fungal Infections in Solid Organ Transplant Recipients: an Indian Perspective

Purpose of Review

This review summarizes the available Indian data on epidemiology of invasive fungal infections (IFI) in recipients of solid organ transplants (SOT). The epidemiology is further compared with studies from other parts of the world for each SOT type.

Recent Findings

The available studies on Indian epidemiology of IFI in SOT are scarce, though the number of SOTs performed in India have increased tremendously in recent years. The limited data from India present a distinct spectrum of infection in transplant recipients with high incidence of mucormycosis. During COVID-19 outbreak, IFI rate increased and renal transplant recipients acquired mucormycosis earlier than previous studies.

Summary

Maximum data on IFI was available from renal transplant recipients, wherein mucormycosis was the predominant IFI in Indian patients in contrast to invasive candidiasis in majority countries. The other IFIs had varied spectrum. With the increasing number of SOTs being performed and the already persisting high burden of IFI in India, there is an urgent need of larger prospective studies on epidemiology of IFI in transplant recipients.

Kidney Transplantation From Infected Donors With Particular Emphasis on Multidrug-Resistant Organisms: A Single-Center Cohort Study

OBJECTIVES

Prevention of sepsis-related organ dysfunction in septic donors is crucial. In this study, septic donors were followed-up based on donor Sequential Organ Failure Assessment criteria.

MATERIALS AND METHODS

Between January 2014 and 2020 at our center, 29 primary kidney transplant recipients received organs from 20 septic donors. All donors received either pathogen-specific or broad-spectrum antibiotics at least 48 hours before procurement, and all recipients received similar treatment posttransplant for an average of 7 to 14 days. Donor eligibility was determined according to the sum of donor-Sequential Organ Failure Assessment scores obtained from 6 parameters: Pao2/Fio2 ratio; platelet count; serum bilirubin, creatinine, and lactate levels; and presence of hypotension. The cut-off value for bacteremic donor acceptance was below 12 points.

RESULTS

Fever (≥38 °C) persisted in 5 donors in the last 24 hours before organ removal. However, in these 5 donors, the mean donor-Sequential Organ Failure Assessment score was 6.5 ± 1.1, mean arterial pressure was >70 mm Hg, and serum lactate levels were <2 mmol/L. Fifteen donors had systemic inflammatory response syndrome scores of ≤2 with corresponding donor-Sequential Organ Failure Assessment scores of 7.9 ± 1.2; none had systemic inflammatory response syndrome scores >3, which would have indicated severe organ failure. In 28 recipients (97%), no donor-related infections were observed in the perioperative first month and afterwards.

CONCLUSIONS

Treatment of donors and recipients with a common protocol greatly reduced the risk of donor-induced infection transmission. In addition, we found the donor-Sequential Organ Failure Assessment criteria to be a helpful tool in predicting organ failure in infected donors.

Consent to organ offers from public health service “Increased Risk” donors decreases time to transplant and waitlist mortality

Background

The Public Health Service Increased Risk designation identified organ donors at increased risk of transmitting hepatitis B, hepatitis C, and human immunodeficiency virus. Despite clear data demonstrating a low absolute risk of disease transmission from these donors, patients are hesitant to consent to receiving organs from these donors. We hypothesize that patients who consent to receiving offers from these donors have decreased time to transplant and decreased waitlist mortality.

Methods

We performed a single-center retrospective review of all-comers waitlisted for liver transplant from 2013 to 2019. The three competing risk events (transplant, death, and removal from transplant list) were analyzed. 1603 patients were included, of which 1244 (77.6%) consented to offers from increased risk donors.

Results

Compared to those who did not consent, those who did had 2.3 times the rate of transplant (SHR 2.29, 95% CI 1.88–2.79, p < 0.0001), with a median time to transplant of 11 months versus 14 months (p < 0.0001), as well as a 44% decrease in the rate of death on the waitlist (SHR 0.56, 95% CI 0.42–0.74, p < 0.0001). All findings remained significant after controlling for the recipient age, race, gender, blood type, and MELD. Of those who did not consent, 63/359 (17.5%) received a transplant, all of which were from standard criteria donors, and of those who did consent, 615/1244 (49.4%) received a transplant, of which 183/615 (29.8%) were from increased risk donors.

Conclusions

The findings of decreased rates of transplantation and increased risk of death on the waiting list by patients who were unwilling to accept risks of viral transmission of 1/300–1/1000 in the worst case scenarios suggests that this consent process may be harmful especially when involving “trigger” words such as HIV. The rigor of the consent process for the use of these organs was recently changed but a broader discussion about informed consent in similar situations is important.

Detection and quantification of human immunodeficiency virus and hepatitis C virus in cadaveric tissue donors using different molecular tests

BACKGROUND

Tissues from cadaveric donors are used in several clinical circumstances, and the transmission of infectious diseases has been reported. Cadaveric donor (CD) blood sample analysis is challenging due to its poor quality. However, studies have demonstrated the usefulness of molecular based methods, and the lack of studies using available commercial molecular tests was reported.

OBJECTIVE

The aim of this study was to evaluate the performance, specificity, sensitivity, and accuracy of different commercial molecular tests for HIV and HCV detection and quantification in CD through spiked samples.

STUDY DESIGN

20 CD and 20 blood donor samples were tested using 1,000 copies/mL and 1,000 IU/mL of lyophilized standards of HIV and HCV, respectively. Samples were analyzed by different molecular kits: XPERT HCV Viral Load and HIV-1 (Cepheid), COBAS® TaqMan® HIV-1 and COBAS® TaqMan® HCV Test, v2.0 (Roche), and artus® HI Virus-1 QS-RGQ and artus® HCV RG RT-PCR Kit (Qiagen).

RESULTS

HIV and HCV in CD were detected by RT-PCR-based quantitative kits. The tests performed by the Cepheid and the Roche kits showed the most accurate, sensitive and specific results, however, a wide variability between the assays and kits was observed. The Qiagen kits did not demonstrate satisfactory results.

CONCLUSIONS

CD evaluation showed great variability. The Cepheid and Roche kits were more sensitive for detecting HIV on CD and Cepheid was the most efficient kit for HCV quantification in CD. The Roche and Cepheid kits can be used to screen tissue donors for HIV and HCV.

Single mutidrug resistant enterobacteriacae donor-derived infection in four solid organ transplant recipients: a case report

Background

Bacteraemia of the donor is not considered to be contraindication of organ procurement. On the other hand, infection of solid organ transplant recipients remains to be a major cause of their morbidity and mortality. When using organs from bacteraemic donors, individual risks need to be assessed and the appropriate antibiotic treatment applied.

Case presentation

In this case series we report several serious donor–derived infectious complications in four out of five recipients of different organs from one single donor in the early posttransplant period. Donor-transmitted multi-drug resistant strains of Escherichia coli and Klebsiella pneumonia was confirmed by both serologic and molecular testing.

Conclusions

To prevent donor-derived infections, careful microbiological screening followed by targeted antibiotic treatment is essential. Although such complications can never by completely prevented, a high index for potential bacterial infection in organ donors and transplant recipients should be routinely employed.

Donor-derived infections, lessons learnt from the past, and what is the future going to bring us

PURPOSE OF REVIEW

Donor-derived transmission of infectious diseases is a well-recognized complication of solid organ transplantation (SOT). Most donor-derived disease transmissions are expected. Although uncommon, unexpected donor-derived infections can be associated with significant morbidity and mortality, and as the volume of patients undergoing SOT increases, the number of infections transmitted through organ donation can also be expected to rise. The growing gap between the number of patients waiting for transplantation and available organs continue in fact to be the number one issue facing the transplant community. As a consequence the major focus in organ transplantation has been developing strategies to increase the available organs, including the use of organs from donors with infections or risky behaviors that have disqualified them from the donation in the past.

RECENT FINDINGS

In addition to the commonly reported donor-derived transmissions, an increasing number of studies have reported unusual infections transmitted by SOT.

SUMMARY

Transplant surgeons and physicians should increase their awareness toward uncommon donor-derived infections including them in the differential diagnosis of unusual clinical pictures in their recipients.

Variation in Assessing Renal Allograft Rejection: A National Assessment of Nephrology Practice

BACKGROUND

The clinical utility of early detection and treatment of allograft rejection is well-established. Despite frequent testing called for by standard of care protocols, the five-year kidney allograft survival rate is estimated to be as low as 71%. Herein, we report on posttransplant care provided to kidney allograft recipients by board-certified nephrologists in the United States.

METHODS

We measured clinical practice in a representative sample of 175 practicing nephrologists. All providers cared for simulated patients' status after renal transplant ranging from 30-75 years in age and 3-24 months after transplant. Our sample of nephrologists cared for a total of 525 allograft cases. Provider responses to the cases were reviewed by trained clinicians, and care was compared to evidence-based care standards and accepted standard of care protocols.

RESULTS

Among nephrologists, practicing in settings ranging from transplant centers to community practice, we found that the clinical workup of kidney injury in posttransplant patients is highly variable and frequently deviates from evidence-based care. In cases with pathologic evidence of rejection, only 29.1% (102/350) received an appropriate, evidence-based biopsy, whereas, in cases with no pathological evidence of rejection, 41.3% (45/109) received low-value, unnecessary biopsies.

CONCLUSION

Clinical care in the posttransplant setting is highly variable. Biopsies are often ordered in cases where their results do not alter treatment. Additionally, we found that misdiagnosis was common as were opportunities for earlier biopsy and detection of rejection. This evidence suggests that better diagnostic tools may be helpful to determine which transplant patients should be biopsied and which should not. This study suggests that nephrologists and transplant patients need better tests than creatinine and proteinuria and less invasive approaches than routine biopsies to determine when transplant patients should be investigated for rejection and additional treatment.

Bidirectional transfer of Anelloviridae lineages between graft and host during lung transplantation

Solid organ transplantation disrupts virus-host relationships, potentially resulting in viral transfer from donor to recipient, reactivation of latent viruses, and new viral infections. Viral transfer, colonization, and reactivation are typically monitored using assays for specific viruses, leaving the behavior of full viral populations (the "virome") understudied. Here we sought to investigate the temporal behavior of viruses from donor lungs and transplant recipients comprehensively. We interrogated the bronchoalveolar lavage and blood viromes during the peritransplant period and 6-16 months posttransplant in 13 donor-recipient pairs using shotgun metagenomic sequencing. Anelloviridae, ubiquitous human commensal viruses, were the most abundant human viruses identified. Herpesviruses, parvoviruses, polyomaviruses, and bacteriophages were also detected. Anelloviridae populations were complex, with some donor organs and hosts harboring multiple contemporaneous lineages. We identified transfer of Anelloviridae lineages from donor organ to recipient serum in 4 of 7 cases that could be queried, and immigration of lineages from recipient serum into the allograft in 6 of 10 such cases. Thus, metagenomic analyses revealed that viral populations move between graft and host in both directions, showing that organ transplantation involves implantation of both the allograft and commensal viral communities.

Emergent Arboviruses and Renal Transplantation: A Global Challenge

In recent years, Zika, Chikungunya, Dengue, West Nile Fever, and Yellow Fever epidemics have generated some concerns. Besides difficulties related to vector control, there are challenges related to behavior of pathologies not yet fully understood. The transplanted population requires additional care due to immunosuppressive drugs. Furthermore, the potential risk of transmission during donation is another source of uncertainty and generates debate among nephrologists in transplant centers. Do the clinical outcomes and prognoses of these infections tend to be more aggressive in this population? Is there a risk of viral transmission via kidney donation? In this review article, we address these issues and discuss the relationship between arbovirus and renal transplantation.

Indian Antimicrobial Prescription Guidelines in Critically Ill Immunocompromised Patients

How to cite this article: Kulkarni AP, Sengar M, Chinnaswamy G, Hegde A, Rodrigues C, Soman R, Khilnani GC, Ramasubban S, Desai M, Pandit R, Khasne R, Shetty A, Gilada T, Bhosale S, Kothekar A, Dixit S, Zirpe K, Mehta Y, Pulinilkunnathil JG, Bhagat V, Khan MS, Narkhede AM, Baliga N, Ammapalli S, Bamne S, Turkar S, Bhat KV, Choudhary J, Kumar R, Divatia JV. Indian Journal of Critical Care Medicine 2019;23(Suppl 1): S64-S96.

Infection in Kidney Transplant Recipients

In organ transplant recipients, impaired inflammatory responses suppress the clinical and radiologic findings of infection. The possible etiologies of infection are diverse, ranging from common bacterial and viral pathogens that affect the entire community to opportunistic pathogens that cause invasive disease only in immunocompromised hosts. Antimicrobial therapies required to treat established infection are often complex, with accompanying risks for drug toxicities and drug interactions with the immunosuppressive agents used to maintain graft function. Rapid and specific diagnosis is essential for successful therapy. The risk of serious infections in the organ transplant patient is largely determined by the interaction between two factors: the patient’s epidemiologic exposures and the patient’s net state of immunosuppression. The epidemiology of infection includes environmental exposures and nosocomial infections, organisms derived from donor tissues, and latent infections from the recipient activated with immunosuppression. The net state of immune suppression is a conceptual framework that measures those factors contributing to risk for infection: the dose, duration, and temporal sequence of immunosuppressive drugs; the presence of foreign bodies or injuries to mucocutaneous barriers; neutropenia; metabolic abnormalities including diabetes; devitalized tissues, hematomas, or effusions postsurgery; and infection with immunomodulating viruses. Multiple factors are present in each host. A timeline exists to aid in the development of a differential diagnosis for infection. The timeline for each patient is altered by changes in prophylaxis and immunosuppressive drugs. For common infections, new microbiologic assays, often nucleic acid based, are useful in the diagnosis and management of opportunistic infections.

Implications of declining donor offers with increased risk of disease transmission on waiting list survival in lung transplantation

BACKGROUND

Donors with characteristics that may increase the likelihood of disease transmission with transplantation are noted as increased risk via Public Health Service criteria. This study aimed to establish the implications of declining an increased-risk donor (IRD) organ offer in lung transplantation.

METHODS

Adult candidates waitlisted for isolated lung transplantation in the United States using the Organ Procurement and Transplantation Network /United Network of Organ Sharing registry from 2007 to 2017 were identified. Individual match run files identified candidate recipients who matched to an IRD offer. Competing-risks analysis ascertained the likelihood of survival to transplantation. A stratified Cox model and restricted mean survival times estimated the survival benefit associated with the acceptance of an IRD organ.

RESULTS

A total of 6,963 candidates met inclusion criteria, and 1,473 (21.2%) accepted an IRD offer. Candidates who accepted an IRD offer were older, more likely to be male, and had a higher lung allocation score at the time of listing (all p < 0.05). At 1 year after an IRD offer decline, 70.5% of candidates underwent a lung transplant, 13.8% died or decompensated, and 14.9% were still awaiting transplant. Compared with those who declined, candidates who accepted the IRD offer had significantly improved cumulative mortality at 1 year (14.1% vs 23.9%, p < 0.001) and 5 years (48.4% vs 53.8%, p < 0.001).

CONCLUSIONS

IRD organ declination is associated with a decreased rate of lung transplantation and worse survival. Overall post-transplant survival rates for those who survive to transplantation are equivalent.

Infectious disease risks in xenotransplantation

Hurdles exist to clinical xenotransplantation including potential infectious transmission from nonhuman species to xenograft recipients. In anticipation of clinical trials of xenotransplantation, the associated infectious risks have been investigated. Swine and immunocompromised humans share some potential pathogens. Swine herpesviruses including porcine cytomegalovirus (PCMV) and porcine lymphotropic herpesvirus (PLHV) are largely species-specific and do not, generally, infect human cells. Human cellular receptors exist for porcine endogenous retrovirus (PERV), which infects certain human-derived cell lines in vitro. PERV-inactivated pigs have been produced recently. Human infection due to PERV has not been described. A screening paradigm can be applied to exclude potential human pathogens from "designated pathogen free" breeding colonies. Various microbiological assays have been developed for screening and diagnosis including antibody-based tests and qualitative and quantitative molecular assays for viruses. Additional assays may be required to diagnose pig-specific organisms in human xenograft recipients. Significant progress has been made in the evaluation of the potential infectious risks of clinical xenotransplantation. Infectious risk would be amplified by intensive immunosuppression. The available data suggest that risks of xenotransplant-associated recipient infection are manageable and that clinical trials can be performed safely. Possible infectious risks of xenotransplantation to the community at large are undefined but merit consideration.

Donor-derived multiorgan transmission of mixed P. malariae and P. ovale infection: Impact of globalization on post-transplant infections

A 57-year-old man was admitted with fever and thrombocytopenia 1 month after renal transplantation. He had never received a blood transfusion or travelled outside Spain. A peripheral blood smear revealed Plasmodium malariae and P. ovale parasites, diagnosis confirmed later by malaria PCR. The donor, from Equatorial Guinea, had negative thick and thin blood smears and rapid malaria antigen test prior to organ donation. Peripheral blood malaria PCR was not performed during donor screening. The second renal recipient and the liver recipient were evaluated and were found to be asymptomatic. Thick and thin films and rapid malaria diagnostic tests were negative for both patients and blood for malaria PCR was sent to the referral laboratory. The index patient was treated with oral chloroquine diphosphate, with a favorable outcome and was considered cured. Malaria PCR was negative for the other renal recipient and positive for P. malariae and P. ovale curtisi for the liver transplant patient. Both were treated with oral chloroquine and the liver recipient also completed treatment with primaquine phosphate. This reported case of multiorgan transmission of mixed malaria infection highlights the importance of PCR-based tests for Plasmodium in the screening of donors from endemic areas.

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

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

Infections in pediatric solid-organ transplant recipients

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

High clinical suspicion of donor-derived disease leads to timely recognition and early intervention to treat solid organ transplant-transmitted lymphocytic choriomeningitis virus

Despite careful donor screening, unexpected donor-derived infections continue to occur in organ transplant recipients (OTRs). Lymphocytic choriomeningitis virus (LCMV) is one such transplant-transmitted infection that in previous reports has resulted in a high mortality among the affected OTRs. We report a LCMV case cluster that occurred 3 weeks post-transplant in three OTRs who received allografts from a common organ donor in March 2013. Following confirmation of LCMV infection at Centers for Disease Control and Prevention, immunosuppression was promptly reduced and ribavirin and/or intravenous immunoglobulin therapy were initiated in OTRs. The liver recipient died, but right kidney recipients survived without significant sequelae and left kidney recipient survived acute LCMV infection with residual mental status deficit. Our series highlights how early recognition led to prompt therapeutic intervention, which may have contributed to more favorable outcome in the kidney transplant recipients.

Infection in Organ Transplantation

The prevention, diagnosis, and management of infectious disease in transplantation are major contributors to improved outcomes in organ transplantation. The risk of serious infections in organ recipients is determined by interactions between the patient's epidemiological exposures and net state of immune suppression. In organ recipients, there is a significant incidence of drug toxicity and a propensity for drug interactions with immunosuppressive agents used to maintain graft function. Thus, every effort must be made to establish specific microbiologic diagnoses to optimize therapy. A timeline can be created to develop a differential diagnosis of infection in transplantation based on common patterns of infectious exposures, immunosuppressive management, and antimicrobial prophylaxis. Application of quantitative molecular microbial assays and advanced antimicrobial therapies have advanced care. Pathogen-specific immunity, genetic polymorphisms in immune responses, and dynamic interactions between the microbiome and the risk of infection are beginning to be explored. The role of infection in the stimulation of alloimmune responses awaits further definition. Major hurdles include the shifting worldwide epidemiology of infections, increasing antimicrobial resistance, suboptimal assays for the microbiologic screening of organ donors, and virus-associated malignancies. Transplant infectious disease remains a key to the clinical and scientific investigation of organ transplantation.

Clinical impact of bacterial contamination of perfusion fluid in kidney transplantation

Contamination of perfusion fluid (PF) could lead to serious infections in kidney transplant recipients. Preemptive therapy (PE-T) in case of yeast contamination of PF is mandatory. The usefulness of PE-T in presence of bacteria remains unclear. In this study we evaluated the incidence of PF bacterial contamination and the impact of PE-T on clinical outcome. Microbiological data of 290 PF and clinical data of the corresponding recipients collected in our hospital from January 2010 and December 2012 were analyzed. Recipients with bacterial contaminated PF (101) were divided in 3 groups: group 1 (n = 52) PE-T treated bacteria resistant to perioperative antibiotic prophylaxis (PAP), group 2 (n = 28) bacteria sensitive to PAP, group 3 (n = 21) PE-T-untreated bacteria resistant to PAP. Incidence of positive PF was 34.8 %, 50.4 % staphylococci, 9.9 % C. albicans. No significant differences in the rate of PF-related infections between the three groups were found. In conclusion, although PF contamination is frequent, the incidence of PF-related infections is very low. In addition, in this study PE-T did not help to reduce the rate of PF-related infection suggesting that a resonable reduction in the use of antibiotic terapy could be made. However, waiting for largest and prospective clinical trials to confirm our findings, a closely clinical and microbiologic monitoring of the recipient is highly recommended in case of PF contamination.

Landscape of Deceased Donors Labeled Increased Risk for Disease Transmission Under New Guidelines

Deceased donors are labeled increased risk for disease transmission (IRD) if they meet certain criteria. New PHS guidelines were recently implemented; the impact of these changes remains unknown. We aimed to quantify the impact of the new guidelines on the proportion of deceased donors labeled IRD, as well as demographic and clinical characteristics. We used Poisson regression with an interaction term for era (new vs. old guidelines) to quantify changes. Under the new guidelines, 19.5% donors were labeled IRD, compared to 10.4%, 12.2%, and 12.3% in the 3 most recent years under the old guidelines (IRR = 1.45, p < 0.001). Increases were consistent across OPOs: 44/59 had an increase in the percent of donors labeled IRD, and 14 OPOs labeled 25% of their donors IRD under the new guidelines (vs. 5 OPOs under the old). African-Americans were 52% more likely to be labeled IRD under the new guidelines (RR = 1.52, p = 0.01). There has been a substantial increase in donors labeled IRD under the new PHS guidelines; it is important to understand the mechanism and consequences to ensure an optimal balance of patient safety and organ utilization is achieved.

Chikungunya infection in a human immunodeficiency virus-infected kidney transplant recipient returning to Italy from the Dominican Republic

Since December 2013, chikungunya virus (CHIKV) spread in many countries of the Western Hemisphere, and during the last year some cases of infected European travelers, coming back from the Caribbean, have been reported. The risk of acquiring severe travel-related illness is higher in immunocompromised subjects, such as patients with human immunodeficiency virus (HIV) infection or solid organ transplant recipients. We reported the first case, to our knowledge, of CHIKV infection in an HIV-infected kidney transplant recipient.

Characterization and risk of blood-borne virus transmission in organ transplantation: what are the priorities?

ABSTRACT 

Blood-borne virus transmission through organ transplantation, although rare, has been associated with severe complications in recipients. There are few data available to ascertain the risk of infection in organ transplantation for known and emerging pathogens, as most information comes from events of transmission, which are rare and not always well characterized. The balance between quality of life through organ transplantation and the risks of donor-derived infection can be improved through advances in donor screening, enhanced monitoring and a multidisciplinary approach to improving donor assessment and recipient biosurveillance. The involvement of investigators with clinical, laboratory, surveillance and policy expertise is critical to bridge research knowledge and clinical practice.

Donor-derived infection--the challenge for transplant safety

Unusual clinical syndromes or clusters of infections in recipients of organs from the same donor suggest donor-derived infection as a possible source of transmission

The incidence of transmission of unexpected infection by organ allografts is low, but precise data are lacking

Screening of donors for common pathogens involves both epidemiologic history and microbiological assays, and is highly effective for preventing the transmission of HIV and hepatitis B and C viruses

Donor screening for uncommon pathogens must be guided by knowledge of changes in the local epidemiology of infection

The key element in the detection of donor-derived infection is suspicion on the part of the clinicians caring for organ recipients

Application of newer microbiological techniques will increase the speed of donor screening and enhance transplant safety

Each year, over 70,000 organs are transplanted worldwide. The degree of risk of transmission of infection from transplanted organs to the recipient is largely unknown and is difficult to assess for specific organs. Here, Jay A. Fishman and Paolo A. Grossi describe the major risk factors for organ donor-derived transmission of infection and discuss opportunities to reduce the incidence of such events.

Organ transplantation, including of the heart, lung, kidney, liver, pancreas, and small bowel, is considered the therapy of choice for end-stage organ failure. Each year, over 70,000 organs are implanted worldwide. One donor may provide multiple organs, as well as corneas and other tissues, for multiple recipients. The degree of risk for transmission of infection carried with grafts, notably of viruses, is largely unknown and, for a specific organ, difficult to assess. The approach to microbiological screening of organ donors varies with national and regional regulations and with the availability and performance of microbiological assays used for potential donors. Transmission of both expected or common, and unexpected infections has been observed in organ transplants, generally recognized after development of clusters of infections among recipients of organs from a common donor. Other than for unusual or catastrophic events, few data exist that define the incidence and manifestations of donor-derived infections or the ideal assays to use in screening to prevent such transmissions. Absolute prevention of the transmission of donor-derived infections in organ transplantation is not possible. However, improvements in screening technologies will enhance the safety of transplantation in the future.

Central nervous system syndromes in solid organ transplant recipients

Solid organ transplant recipients have a high incidence of central nervous system (CNS) complications, including both focal and diffuse neurologic deficits. In the immunocompromised host, the initial clinical evaluation must focus on both life-threatening CNS infections and vascular or anatomic lesions. The clinical signs and symptoms of CNS processes are modified by the immunosuppression required to prevent graft rejection. In this population, these etiologies often coexist with drug toxicities and metabolic abnormalities that complicate the development of a specific approach to clinical management. This review assesses the multiple risk factors for CNS processes in solid organ transplant recipients and establishes a timeline to assist in the evaluation and management of these complex patients.

Bacterial infection after liver transplantation

Infectious complications are major causes of morbidity and mortality after liver transplantation, despite recent advances in the transplant field. Bacteria, fungi, viruses and parasites can cause infection before and after transplantation. Among them, bacterial infections are predominant during the first two months post-transplantation and affect patient and graft survival. They might cause surgical site infections, including deep intra-abdominal infections, bacteremia, pneumonia, catheter-related infections and urinary tract infections. The risk factors for bacterial infections differ between the periods after transplant, and between centers. Recently, the emergence of multi-drug resistant bacteria is great concern in liver transplant (LT) patients. The instructive data about effects of infections with extended-spectrum beta lactamase producing bacteria, carbapenem-resistant gram-negative bacteria, and glycopeptide-resistant gram-positive bacteria were reported on a center-by-center basis. To prevent post-transplant bacterial infections, proper strategies need to be established based upon center-specific data and evidence from well-controlled studies. This article reviewed the recent epidemiological data, risk factors for each type of infections and important clinical issues in bacterial infection after LT.

Management of infections pre- and post-liver transplantation: report of an AISF consensus conference

The burden of infectious diseases both before and after liver transplantation is clearly attributable to the dysfunction of defensive mechanisms of the host, both as a result of cirrhosis, as well as the use of immunosuppressive agents. The present document represents the recommendations of an expert panel commended by the Italian Association for the Study of the Liver (AISF), on the prevention and management of infectious complications excluding hepatitis B, D, C, and HIV in the setting of liver transplantation. Due to a decreased response to vaccinations in cirrhosis as well as within the first six months after transplantation, the best timing for immunization is likely before transplant and early in the course of disease. Before transplantation, a vaccination panel including inactivated as well as live attenuated vaccines is recommended, while oral polio vaccine, Calmette-Guerin's bacillus, and Smallpox are contraindicated, whereas after transplantation, live attenuated vaccines are contraindicated. Before transplant, screening protocols should be divided into different levels according to the likelihood of infection, in order to reduce costs for the National Health Service. Recommended preoperative and postoperative prophylaxis varies according to the pathologic agent to which it is directed (bacterial vs. viral vs. fungal). Timing after transplantation greatly determines the most likely agent involved in post-transplant infections, and specific high-risk categories of patients have been identified that warrant closer surveillance. Clearly, specifically targeted treatment protocols are needed upon diagnosis of infections in both the pre- as well as the post-transplant scenarios, not without considering local microbiology and resistance patterns.

Cryptococcal infections: changing epidemiology and implications for therapy

Although the incidence of HIV-associated cryptococcosis has decreased in developed countries since the introduction of antiretroviral therapy, this disease continues to cause significant morbidity and mortality in sub-Saharan Africa among patients with AIDS. Important strides have been made in an attempt to decrease the burden of disease, particularly the development of the lateral flow assay cryptococcal antigen (LFA CrAg) as a diagnostic tool in resource-limited settings, coupled with the introduction of pre-emptive treatment with fluconazole for HIV-positive patients at risk for cryptococcosis with a positive LFA CrAg. Among solid organ transplant recipients, recent prospective studies have identified cryptococcosis as the third most common invasive fungal infection, and progress is being made toward earlier diagnosis and more effective therapy. Finally, the Cryptococcus gattii outbreak in British Columbia, Canada and the US Pacific Northwest is providing important new insights into the emergence of this pathogen in geographic areas previously considered low risk for acquisition of infection. Understanding the similarities and differences among C. gattii and C. neoformans infections will provide critical insights into the behavior of these organisms in the human host. Both pathogens affect immunocompetent and immunosuppressed hosts, causing pulmonary, central nervous system and widely disseminated infections. Treatment recommendations in the future will necessarily take into account the site of infection, clinical severity of the infection, Cryptococcus species, host immune status and economic resources.

Opportunistic infections--coming to the limits of immunosuppression?

Possible etiologies of infection in the solid organ recipient are diverse, ranging from common bacterial and viral pathogens to opportunistic pathogens that cause invasive disease only in immunocompromised hosts. The recognition of infectious syndromes in this population is limited by alterations in the clinical manifestations by immunosuppression. The risk of serious infections in the organ transplant patient is determined by the interaction between the patients' recent and distant epidemiological exposures and all factors that contribute to the patient's net state of immune suppression. This risk is altered by antimicrobial prophylaxis and changes in immunosuppressive therapies. In addition to the direct effects of infection, opportunistic infections, and the microbiome may adversely shape the host immune responses with diminished graft and patient survivals. Antimicrobial therapies are more complex than in the normal host with a significant incidence of drug toxicity and a propensity for drug interactions with the immunosuppressive agents used to maintain graft function. Rapid and specific microbiologic diagnosis is essential. Newer microbiologic assays have improved the diagnosis and management of opportunistic infections. These tools coupled with assays that assess immune responses to infection and to graft antigens may allow optimization of management for graft recipients in the future.

Clinical and microbial impact of screening kidney allograft preservative solution for bacterial contamination with high-sensitivity methods

The clinical and bacteriological consequences of routinely performing highly sensitive bacterial screening of kidney transplant preservation solution (PS) are not known. To evaluate the clinical and microbiological impacts of this strategy, we retrospectively analyzed 200 consecutive kidney allograft recipients from March 2009 to February 2011 for whom PS samples were routinely screened. PS were inoculated into aerobic and anaerobic blood culture bottles, as well as blood agar plates. A rectal swab for extended-spectrum β-lactamase-producing Enterobacteriaceae (EBSL-PE) faecal carriage was also routinely obtained from each patient at admission and every 7 days until hospital discharge. In addition, a standard culture of drain fluid was collected on the day after kidney transplantation. Complete samples and cultures of PS were performed in 165 cases (82.5%), and 62 (37.6%) had positive blood culture results. The most frequent microbial agent isolated was coagulase-negative staphylococci (51.8%). Of these 62 positive samples, only seven (11.3%) were confirmed to contain the same organism by the standard culture method. Drain fluid and PS culture positivity with the same microorganism occurred in only two patients. Of the 62 patients with positive PS cultures, 26 (41.9%) received pre-emptive antibiotic therapy initiated within 48 h post-transplant. During the hospitalization period, patients with a positive PS culture, regardless of whether they received pre-emptive antibiotic therapy, did not exhibit any invasive infections (urinary, blood, peritoneal or wound) related to the microorganisms isolated in the PS. Patients with positive PS cultures who were treated with antibiotic therapy acquired significantly more colonizing ESBL-PE than patients who did not receive antibiotics (53.8% vs. 16.6%; P = 0.01); these patients also developed more clinical infections related to the ESBL-PE (23.1% vs. 5.2%; P < 0.01). The use of antibiotics for patients with positive PS cultures was an independent risk factor for ESBL-PE acquisition in both univariate and multivariate analyses. In conclusion, the use of more sensitive culture methods increases the rate of bacterial contamination of PS and is associated with an increased prescription of antibiotics and increased ESBL-PE carriage and related infections. Therefore, the systematic use of PS blood bottle cultures in kidney transplantation may have no benefit and might increase the rate of ESBL-PE emergence.

Donor-derived bacteremia in liver transplant recipients despite antibiotic prophylaxis

As the disparity between the number of candidates listed for transplant and the number of donors continues to grow, marginal organ donors are increasingly utilized. This includes bacteremic donors which may carry an increased risk of transmission of infection. It is recommended that recipients of organs from bacteremic donors receive antibiotic prophylaxis based on the susceptibilities of the donor isolate to prevent transmission. Here, we present four cases of donor-derived bacteremia, despite appropriate antimicrobial prophylaxis, in four liver transplant recipients. Transmitted pathogens included Staphylococcus aureus in two cases, and Escherichia coli and Group B Streptococcus each in one case. Interestingly, none of the nonhepatic organs (n=10) utilized from these bacteremic donors resulted in transmissions. These cases highlight the fact that risk of transmission from bacteremic donors is not eliminated with antimicrobial therapy in the donor and recipient. As no transmissions occurred in recipients of nonhepatic organs from these donors, these cases also suggest that liver recipients may be at higher risk of donor transmitted bacteremia.

Evaluating the risk of transmission of infection from donor to recipient of a solid organ transplantation

In the context of solid organ transplantation, screening of potential organ donors is crucial, and should be performed with great rigor to minimize the risk of transmission of certain infectious processes. This review aims to update understanding of the possible pathologies involved, as well as of emerging infections that, as a result of globalization, are gaining increasing prominence on a daily basis.

Invasive fungal infections in solid organ transplant recipients

Invasive fungal infections are a major problem in solid organ transplant (SOT) recipients. Overall, the most common fungal infection in SOT is candidiasis, followed by aspergillosis and cryptococcosis, except in lung transplant recipients, where aspergillosis is most common. Development of invasive disease hinges on the interplay between host factors (e.g., integrity of anatomical barriers, innate and acquired immunity) and fungal factors (e.g., exposure, virulence and resistance to prophylaxis). In this article, we describe the epidemiology and clinical features of the most common fungal infections in organ transplantation. Within this context, we review recent advances in diagnostic modalities and antifungal chemotherapy, and their impact on evolving prophylaxis and treatment paradigms.