Infections in pediatric solid organ transplant recipients

Comparative Effectiveness of Perioperative Antibiotic Regimens to Prevent Surgical Site Infections in Pediatric Liver Transplant Recipients

BACKGROUND

Surgical site infections (SSIs) are a common complication in liver transplant (LT) recipients. Lack of pediatric prophylaxis guidelines results in variation in preventative antibiotic regimens.

METHODS

We performed a retrospective observational study of LT recipients <18 years old using a merged data set that included data from the Pediatric Health Information System and the United Network for Organ Sharing between 2006 and 2017. The exposure was defined as the antibiotic(s) received within 24 hours of LT, with 6 categories, ranging from narrow (category 1: cefazolin), to broad). The primary outcome was presence or absence of SSI in the index admission. Mixed-effects logistic regression compared the effectiveness of each category in preventing SSI, relative to category 1.

RESULTS

Of the 2586 LT, 284 (11%) met SSI criteria. The SSI rate was higher in the younger subcohort (16.2%) than in the older (8.6%), necessitating a stratified analysis. Antibiotics from category 5 were most commonly used. In the younger subcohort, the adjusted risk was increased in all categories compared with the reference, most notably in category 3 (odds ratio [OR], 2.58 [95% confidence interval: .69-9.59]) and category 6 (2.76 [.66-11.56]). In the older subcohort, estimated ORs were also increased for each category, most notably in category 4 (2.49 [95% confidence interval: .99-6.27]). None of the ORs suggested benefit from broader-spectrum prophylaxis. Our E-value assessment suggests that it's unlikely there is unmeasured confounding by indication to the degree necessary to revert ORs to protective.

CONCLUSIONS

There was wide variation in antibiotic prophylaxis. Adjusted analyses did not reveal a protective benefit of broader-spectrum prophylaxis in either subcohort, suggesting that narrower regimens may be adequate.

Vaccination practices in pediatric transplantation: A survey among member centers of the European reference network TransplantChild

BACKGROUND

There is considerable variation in vaccination practices between pediatric transplant centers. This study aims to evaluate active immunization attitudes and practices among ERN-TransplantChild centers and identify potential areas of improvement that could be addressed by shared evidence-based protocols.

METHODS

A cross-sectional questionnaire of attitudes and practices toward immunization of pediatric SOT and HSCT candidates and recipients was sent to a representative member of multidisciplinary teams from 27 European centers belonging to the ERN-TransplantChild.

RESULTS

A total of 28/62 SOT programs and 6/12 HSCT programs across 21 European centers participated. A quarter of centers did not have an on-site protocol for the immunizations. At the time of transplantation, pediatric candidates were fully immunized (80%-100%) in 57% and 33% of the SOT and HSCT programs. Variations in the time between vaccine administration and admission to the waiting list were reported between the centers, with 2 weeks for inactivated vaccines and variable time (2-4 weeks) for live-attenuated vaccines (LAVs). Almost all sites recommended immunization in the post-transplant period, with a time window of 4-8 months for the inactivated vaccines and 16-24 months for MMR and Varicella vaccines. Only five sites administer LAVs after transplantation, with seroconversion evaluated in 80% of cases.

CONCLUSIONS

The immunization coverage of European pediatric transplant recipients is still inconsistent and far from adequate. This survey is a starting point for developing shared evidence-based immunization protocols for safe vaccination among pediatric transplant centers and generating new research studies.

Multidrug-resistant organisms: A significant cause of severe sepsis in pediatric intestinal and multi-visceral transplantation

Severe sepsis in immunocompromised children is associated with increased mortality. This paper describes the epidemiology landscape, clinical acuity, and outcomes for severe sepsis in pediatric intestinal (ITx) and multi-visceral (MVTx) transplant recipients requiring admission to the pediatric intensive care unit (PICU). Severe sepsis episodes were retrospectively reviewed in 51 ITx and MVTx patients receiving organs between 2009 and 2015. Twenty-nine (56.8%) patients had at least one sepsis episode (total of 63 episodes) through December 2016. Bacterial etiologies accounted for 66.7% of all episodes (n = 42), occurring a median of 122.5 days following transplant (IQR 59-211.8 days). Multidrug-resistant organisms (MDROs) accounted for 73.8% of bacterial infections; extended spectrum beta-lactamase producers, vancomycin-resistant enterococcus, and highly-resistant Pseudomonas aeruginosa were the most commonly identified. Increased mechanical ventilation and vasoactive requirements were noted in MDRO episodes (OR 3.03, 95% CI 1.09-8.46 and OR 3.07, 95% CI 1.09-8.61, respectively; p < .05) compared to non-MDRO episodes. PICU length of stay was significantly increased for MDRO episodes (7 vs. 3 days, p = .02). Graft loss was 24.1% (n = 7) and mortality was 24.1% (n = 7) in patients who experienced severe sepsis. Further attention is needed for MDRO risk mitigation and modification of sepsis treatment guidelines to ensure MDRO coverage for this population.

Epidemiology and long-term outcomes of cytomegalovirus DNAemia and disease in pediatric solid organ transplant recipients

Despite prevention strategies, cytomegalovirus (CMV) remains a common infection in pediatric solid organ transplant recipients (SOTR). We sought to determine the frequency, associations with, and long-term outcomes of CMV DNAemia in pediatric SOTR. We performed a single-center retrospective cohort study, including 687 first time SOTR ≤21 years receiving universal prophylaxis from 2011 to 2018. Overall, 159 (23%) developed CMV DNAemia, the majority occurring after completing primary prophylaxis. CMV disease occurred in 33 (5%) SOTR, 25 (4%) with CMV syndrome and 10 (1%) with proven/probable tissue-invasive disease. CMV contributed to the death of three (0.4%) patients (all lung). High-risk (OR 6.86 [95% CI, 3.6-12.9]) and intermediate-risk (4.36 [2.3-8.2]) CMV status and lung transplantation (4.63 [2.33-9.2]) were associated with DNAemia on multivariable analysis. DNAemia was associated with rejection in liver transplant recipients (p < .01). DNAemia was not associated with an increase in graft failure, all-cause mortality, or other organ-specific poor outcomes. We report one of the lowest rates of CMV disease after SOTR, showing that universal prophylaxis is effective and should be continued. However, we observed CMV morbidity and mortality in a subset of patients, highlighting the need for research on optimal prevention strategies. This study was IRB approved.

Perioperative blood transfusion decreases long-term survival in pediatric living donor liver transplantation

BACKGROUND

The impact of perioperative blood transfusion on short- and long-term outcomes in pediatric living donor liver transplantation (PLDLT) must still be ascertained, mainly among young children. Clinical and surgical postoperative complications related to perioperative blood transfusion are well described up to three months after adult liver transplantation.

AIM

To determine whether transfusion is associated with early and late postoperative complications and mortality in small patients undergoing PLDLT.

METHODS

We evaluated the effects of perioperative transfusion on postoperative complications in recipients up to 20 kg of body weight, submitted to PLDLT. A total of 240 patients were retrospectively allocated into two groups according to postoperative complications: Minor complications (n = 109) and major complications (n = 131). Multiple logistic regression analysis identified the volume of perioperative packed red blood cells (RBC) transfusion as the only independent risk factor for major postoperative complications. The receiver operating characteristic curve was drawn to identify the optimal volume of the perioperative RBC transfusion related to the presence of major postoperative complications, defining a cutoff point of 27.5 mL/kg. Subsequently, patients were reallocated to a low-volume transfusion group (LTr; n = 103, RBC ≤ 27.5 mL/kg) and a high-volume transfusion group (HTr; n = 137, RBC > 27.5 mL/kg) so that the outcome could be analyzed.

RESULTS

High-volume transfusion was associated with an increased number of major complications and mortality during hospitalization up to a 10-year follow-up period. During a short-term period, the HTr showed an increase in major infectious, cardiovascular, respiratory, and bleeding complications, with a decrease in rejection complications compared to the LTr. Over a long-term period, the HTr showed an increase in major infectious, cardiovascular, respiratory, and minor neoplastic complications, with a decrease in rejection complications. Additionally, Cox hazard regression found that high-volume RBC transfusion increased the mortality risk by 3.031-fold compared to low-volume transfusion. The Kaplan-Meier survival curves of the studied groups were compared using log-rank tests and the analysis showed significantly decreased graft survival, but with no impact in patient survival related to major complications. On the other hand, there was a significant decrease in both graft and patient survival, with high-volume RBC transfusion.

CONCLUSION

Transfusion of RBC volume higher than 27.5 mL/kg during the perioperative period is associated with a significant increase in short- and long-term postoperative morbidity and mortality after PLDLT.

Cancer morbidity and mortality after pediatric solid organ transplantation-a nationwide register study

BACKGROUND

The prevalence of malignancies after pediatric solid organ transplantation was evaluated in a nationwide study.

METHODS

All patients who had undergone kidney, liver, or heart transplantation during childhood between the years 1982 and 2015 in Finland were identified. The inclusion criteria were age under 16 years at transplantation and age over 18 years at the last follow-up day. A total of 233 (137 kidney, 53 liver, and 43 heart) transplant recipients were enrolled. Controls (n = 1157) matched by the year of birth, gender, and hometown were identified using the Population Register Center registry. The cancer diagnoses were searched using the Finnish Cancer Registry.

RESULTS

Altogether 26 individuals diagnosed with cancer were found, including 18 transplant recipients. Cancer was diagnosed at a median of 12.0 (IQR 7.8-17.8) years after the transplantation. The transplant recipients' risk for cancer was significantly higher when compared with the controls (HR 14.7; 95% CI 6.4-33.9). There was no difference for different graft types. Sixty-one percent of cancers among the transplant recipients were diagnosed at age older than 18 years.

CONCLUSION

The risk for cancer is significantly higher among young adults having undergone solid organ transplantation during childhood in comparison with population controls. Careful follow-up and attention to prevent cancers throughout adulthood are warranted.

Under-immunization of pediatric transplant recipients: a call to action for the pediatric community

Vaccine-preventable infections (VPIs) are a common and serious complication following transplantation. One in six pediatric solid organ transplant recipients is hospitalized with a VPI in the first 5 years following transplant and these hospitalizations result in significant morbidity, mortality, graft injury, and cost. Immunizations are a minimally invasive, cost-effective approach to reducing the incidence of VPIs. Despite published recommendations for transplant candidates to receive all age-appropriate immunizations, under-immunization remains a significant problem, with the majority of transplant recipients not up-to-date on age-appropriate immunizations at the time of transplant. This is extremely concerning as the rate for non-medical vaccine exemptions in the United States (US) is increasing, decreasing the reliability of herd immunity to protect patients undergoing transplant from VPIs. There is an urgent need to better understand barriers to vaccinating this population of high-risk children and to develop effective interventions to overcome these barriers and improve immunization rates. Strengthened national policies requiring complete age-appropriate immunization for non-emergent transplant candidates, along with improved multi-disciplinary immunization practices and tools to facilitate and ensure complete immunization delivery to this high-risk population, are needed to ensure that we do everything possible to prevent infectious complications in pediatric transplant recipients.

Pediatric vascularized composite allotransplantation: What is the landscape for obtaining appropriate donors in the United States?

Listing the world's first pediatric bilateral hand transplant patient for a donor posed many challenges including matching the appropriate donor age, bone size, skin tone, and growth potential in an already limited donor population. This study describes the prevalence and distribution of potential pediatric VCA donors in the United States. We assessed the UNOS database from 2008 to 2015 to identify the prevalence of potential pediatric VCA donors. Standard VCA inclusion and exclusion criteria were applied to the dataset for all pediatric solid organ donors. Frequency analyses were performed of characteristics important for VCA matching. The dataset began with 57 300 brain-dead donors and after applying the inclusion and exclusion criteria including age <18, decreased to 4663 (8.1%). The number of pediatric potential VCA donors per UNOS region ranged from 11 to 112/year. The majority of pediatric potential VCA donors were blood type O Whites, with the least common profile being blood type AB of "other" ethnicity. The present study confirmed that pediatric VCA donors are rare and may require longer travel times for procurement and listing at multiple centers in order to find a suitable donor. This will be a limiting factor for the expansion of pediatric VCA.

Non-viral infections in children after renal transplantation

Renal transplantation has long been recognised as the gold standard treatment for children with end-stage renal failure. There has been an improvement over the years in patient and renal allograft survival because of improved immunosuppression, surgical techniques and living kidney donation. Despite reduced acute allograft rejection rates, non-viral infections continue to be a serious complication for paediatric renal transplant recipients (RTR). The risk of infections in RTR is determined by the pre-transplantation immunisation status, post-transplant exposure to potential pathogens and the amount of immunosuppression. The greatest risk of life-threatening and Cytomegalovirus infections is during the first 6 months post-transplant owing to a high immunosuppressive burden. The potential sources of bacterial infections are donor derived, transplant medium fluid, peritoneal and haemodialysis catheter and transplant ureteric stent. Urinary tract infections are frequent in patients with lower urinary tract dysfunction and can result in renal allograft damage. This review outlines the incidence, timing, risk factors, prevention and treatment of non-viral infections in paediatric RTR by critically reviewing current immunosuppressive regimens, their risk-benefit ratio in order to optimise renal allograft survival with reduced rates of rejection and infectious complications.

PDIA3 mRNA expression and IL-2, IL-4, IL-6, and CRP levels of acute kidney allograft rejection in rat

Kidney transplantation to treat end-stage renal disease has evolved rapidly from the first successful transplantations to the current widespread use of grafts from both cadaveric and living donors. But acute rejection is still a strong risk factor for chronic rejection in recipients of renal grafts. To investigate possible mechanisms, we describe a comparison between differentially proteins expression and immune markers profile (IL-2, IL-4, IL-6, and CRP) of acute rejection and the controls. Through quantitative real-time RT-PCR confirmation, PDIA3 mRNA and protein expression levels in serum and transplanted kidney in experiment group was significantly (P < 0.05) higher than that in control group. Immunity analysis showed that plasma IL-2, IL-4, IL-6, and CRP levels were higher in experimental rats than those in control rats. Our data thus indicate that PDIA3 might be potentially involve into the occurence and development of acute rejection response in renal transplantation and increased plasma IL-2, IL-4, IL-6, and CRP levels play an important role to prevent acute kidney allograft rejection in rats.

Psychiatric issues in pediatric organ transplantation

Solid organ transplantation has become the first line of treatment for a growing number of life-threatening pediatric illnesses. With improved survival, research into the long-term outcome of transplant recipients has become important to clinicians. Adherence to medical instructions remains a challenge, particularly in the adolescent population. New immunosuppressant approaches promise to expand organ transplantation in additional directions. Extension of transplantation into replacement of organs such as faces and hands raises complex ethical issues.

Analytic Review: Neurological Complications of Transplantation

Recipients of solid organ or hematopoietic cell transplants are at risk of life-threatening neurological disorders including encephalopathy, seizures, infections and tumors of the central nervous system, stroke, central pontine myelinolysis, and neuromuscular disorders—often requiring admission to, or occurring in, the intensive care unit (ICU). Many of these complications are linked directly or indirectly to immunosuppressive therapy. However, neurological disorders may also result from graft versus host disease, or be an expression of the underlying disease which prompted transplantation, as well as injury induced during radiation, chemotherapy, surgery, and ICU stay. In rare cases, neuroinfectious pathogens may be transmitted with the transplanted tissue or organ. Diagnosis may be a challenge because clinical symptoms and findings on neuroimaging lack specificity, and a biological specimen or tissue diagnosis is often needed for definitive diagnosis. Management is centered on preventing further neurological injury, etiology-targeted therapy, and balancing the benefits and toxicities of specific immunosuppressive agents.

Impaired cellular immune response to diphtheria and tetanus vaccines in children after thoracic transplantation

Safety and immunogenicity of diphtheria and tetanus booster vaccination were evaluated in 28 children after thoracic transplantation. Adverse events were documented in a patient diary. Blood was collected prior to and four wk after vaccination. Specific antibody concentrations were measured by ELISA. Lymphocytes were investigated for expression of activation markers (CD25, HLA-DR) by flow cytometry and proliferation assays with and without stimulation. Post-vaccination antibody titers were higher than prevaccination (p < 0.001), with more patients having protective antibody levels against diphtheria (p < 0.02) and tetanus (p < 0.001). There was no increased proliferation in non-stimulated or stimulated cultures after vaccination. The number of T-lymphocytes activated by the vaccination antigens was similar pre- and post-vaccination, whereas HLA-DR-expression on stimulated and non-stimulated CD4(+) T-cells increased significantly. Increase in antibodies was negatively correlated with tacrolimus dose, and impaired cellular immunity was associated with higher tacrolimus dose and steroid use. Adverse events were similar to the general population; serious adverse events and rejection did not occur. Vaccination with inactivated vaccines can be performed safely in immunosuppressed children after thoracic transplantation and induces protective antibody levels in the majority of patients. Impaired induction of specific cellular immunity is correlated with intensity of immunosuppression and may explain reduced sustainability of antibodies.

Solid-organ transplantation in childhood: transitioning to adult health care

Pediatric solid-organ transplantation is an increasingly successful treatment for solid-organ failure. With dramatic improvements in patient survival rates over the last several decades, there has been a corresponding emergence of complications attributable to pretransplant factors, transplantation itself, and the management of transplantation with effective immunosuppression. The predominant solid-organ transplantation sequelae are medical and psychosocial. These sequelae have a substantial effect on transition to adult care; as such, hurdles to successful transition of care arise from the patients, their families, and pediatric and adult health care providers. Crucial to successful transitioning is the ongoing development of a sense of autonomy and responsibility for one's own care. In this article we address the barriers to transitioning that occur with long-term survival in pediatric solid-organ transplantation. Although a particular transitioning model is not promoted, practical tools and strategies that contribute to successful transitioning of pediatric patients who have received a transplant are suggested.

Invasive Candida infections in solid organ transplant recipient children

Solid organ transplantation (SOT) is now an accepted therapy for many end-stage organ disorders and fungal infections are the principal cause of infection-related mortality in SOT recipients. Among invasive fungal infections, Candida species are the most common pathogens identified, associated with high mortality rates. The epidemiology and clinical manifestations of Candida infections vary with the type of organ transplantation. This article reviews invasive Candida infections in pediatric SOT recipients.

Invasive mould infections in newborns and children

Invasive mould infections represent important complications of different pediatric conditions. Epidemiology and clinical features vary according to the type of underlying conditions that determine the risk of invasive mycosis. No pediatric study has specifically evaluated the efficacy of prophylaxis or therapy invasive moulds infections, while pediatric dosages for the treatment of invasive aspergillosis are available for drugs that produced positive results in clinical trials undertaken in adults.

Outcomes in pediatric solid-organ transplantation

LaR Pediatric solid-organ transplantation is an increasingly successful treatment for organ failure. Five- and 10-yr patient survival rates have dramatically improved over the last couple of decades, and currently, over 80% of pediatric patients survive into adolescence and young adulthood. Waiting list mortality has been a concern for liver, heart, and intestinal transplantation, illustrating the importance of transplant as a life-saving therapy. Unfortunately, the success of pediatric transplantation comes at the cost of long-term or late complications that arise as a result of allograft rejection or injury, immunosuppression-related morbidity, or both. As transplant recipients enter adolescence treatment, non-adherence becomes a significant issue, and the medical and psychosocial impacts transition to adulthood not only with regard to healthcare but also in terms of functional outcomes, economic potential, and overall QoL. This review addresses the clinical and psychosocial challenges encountered by pediatric transplant recipients in the current era. A better understanding of pediatric transplant outcomes and adult morbidity and mortality requires further ongoing assessment.

Quality of surgical care in liver and small-bowel transplant: approach to risk assessment and antibiotic prophylaxis

In August 2002, The Centers for Medicare and Medicaid Services and the Centers for Disease Control and Prevention implemented the National Surgical Infection Prevention project. The goal of the project was to decrease the morbidity and mortality associated with postoperative surgical site infections through appropriate selection and timing of administration and discontinuation of prophylactic antimicrobials. The National Surgical Infection Prevention project, however, excluded transplant surgeries from its focus because of the lack of randomized clinical trials comparing antimicrobial agents. The goals of this article are to (1) provide a framework for risk factors associated with surgical site infections in liver, small-bowel, and multivisceral transplants; (2) review general principles of the appropriate antimicrobial prophylaxis; (3) provide a framework for developing a triage of liver, small-bowel, and multivisceral transplant candidates for appropriate antibiotic prophylaxis; and (4) develop an approach to further quality improvements in transplant surgical care. A multidisciplinary team produced recommendations for antibacterial prophylaxis and monitoring.

Quality of Surgical Care in Liver and Small-Bowel Transplant: Approach to Risk Assessment and Antibiotic Prophylaxis

In August 2002, The Centers for Medicare and Medicaid Services and the Centers for Disease Control and Prevention implemented the National Surgical Infection Prevention project. The goal of the project was to decrease the morbidity and mortality associated with postoperative surgical site infections through appropriate selection and timing of administration and discontinuation of prophylactic antimicrobials. The National Surgical Infection Prevention project, however, excluded transplant surgeries from its focus because of the lack of randomized clinical trials comparing antimicrobial agents. The goals of this article are to (1) provide a framework for risk factors associated with surgical site infections in liver, small-bowel, and multivisceral transplants; (2) review general principles of the appropriate antimicrobial prophylaxis; (3) provide a framework for developing a triage of liver, small-bowel, and multivisceral transplant candidates for appropriate antibiotic prophylaxis; and (4) develop an approach to further quality improvements in transplant surgical care. A multidisciplinary team produced recommendations for antibacterial prophylaxis and monitoring.

Psychiatric issues in pediatric organ transplantation

Solid organ transplantation has become the first line of treatment for a growing number of life-threatening pediatric illnesses. With improved survival, research into the long-term outcome of transplant recipients has become important to clinicians. Adherence to medical instructions remains a challenge, particularly in the adolescent population. New immunosuppressant approaches promise to expand organ transplantation in additional directions. Extension of transplantation into replacement of organs such as faces and hands raises complex ethical issues.

Neurologic manifestations of transplant complications

Neurologic complications affect posttransplant recovery of more than 20% of transplant recipients. Etiology is usually related to surgical procedure of transplantation, primary disorders causing failure of transplanted organ, opportunistic infections, and neurotoxicity of immunosuppressive medications. Risk of opportunistic infections and immunosuppressant neurotoxicity is greatest within the first six months, but it persists along with long-term maintenance immunosuppression required to prevent graft rejection. Neurotoxicity may require alteration of immunosuppressive regimen, and prompt therapy of opportunistic infections improves outcomes.

Respiratory syncytial virus prophylaxis: a survey of pediatric solid organ transplant centers

RSV can cause respiratory illness after SOT, yet preventive recommendations are lacking for this population. To ascertain current preventive practices against RSV disease in pediatric SOT candidates and recipients, a survey was developed. The survey was mailed to 108 SOT programs in the United States (liver, 42; heart, 28; lung, 11; intestinal, 25; and heart-lung, 2). Results were tabulated and analyzed using standard methods. Sixty-two percent (67/108) of surveys were completed. Forty-nine percent (33/67) of programs reported using RSV prophylaxis; palivizumab was used at 97% (32/33) of centers with 26 giving palivizumab to candidates and 27 to recipients. Prophylaxis was provided to infants aged 0-12 months by 27/29 (93%) of responding centers; 23/29 of centers extended its use to infants aged 0-24 months. Three centers gave prophylaxis to children between ages two and four yr and two centers for those over four yr. RSV prophylactic strategies, and in particular the use of palivizumab, are employed by almost 50% of responding pediatric SOT centers. Strategies varied at centers based on age and organ type. Data on RSV hospitalization and outcome are needed to refine approaches to RSV immunoprophylaxis in these high-risk patients.

Prospective study of infectious complications in a cohort of pediatric renal transplant recipients

Infections are frequent and serious in pediatric RT recipients; however, the information available is scarce. The aim of this study was to determine the incidence, etiology, and risk factors for infection in these patients. This was a prospective, observational study of a consecutive pediatric RT recipient cohort. Risk factors for infection and descriptive analyses during the first two post-transplantation years were performed. Twenty-one patients (58.3%) had at least one infection (incidence 1.5 episodes/patient/first year of transplantation). There were 33 bacterial infections (73.3%), 11 viral infections (24.4%), and one protozoal infection. UTI was the most common syndrome (48.3%), followed by CMV infection (15.5%). The main microorganisms isolated were Escherichia coli (28.9%), 46.1% of which were ESBL producers, and CMV (20%). Patient and graft survival at the end of follow-up were 97.2% and 83.3%, respectively. The only risk factor for infection was cold ischemia time >800 min (OR 5.7, CI 95% 1.7-19.3).

CONCLUSIONS

In pediatric RT recipients, UTI is the most frequent syndrome. Bacterial infections are the most common, with a high rate of ESBL producer strains. Despite their good prognosis, infections are a cause of morbidity that could potentially be reduced by decreasing cold ischemia times.