The use and value of procalcitonin in solid organ transplantation

Progress in Procalcitonin Detection Based on Immunoassay

Procalcitonin (PCT) serves as a crucial biomarker utilized in diverse clinical contexts, including sepsis diagnosis and emergency departments. Its applications extend to identifying pathogens, assessing infection severity, guiding drug administration, and implementing theranostic strategies. However, current clinical deployed methods cannot meet the needs for accurate or real-time quantitative monitoring of PCT. This review aims to introduce these emerging PCT immunoassay technologies, focusing on analyzing their advantages in improving detection performances, such as easy operation and high precision. The fundamental principles and characteristics of state-of-the-art methods are first introduced, including chemiluminescence, immunofluorescence, latex-enhanced turbidity, enzyme-linked immunosorbent, colloidal gold immunochromatography, and radioimmunoassay. Then, improved methods using new materials and new technologies are briefly described, for instance, the combination with responsive nanomaterials, Raman spectroscopy, and digital microfluidics. Finally, the detection performance parameters of these methods and the clinical importance of PCT detection are also discussed.

Development of a Risk Prediction Model for Infection After Kidney Transplantation Transmitted from Bacterial Contaminated Preservation Solution

Background

The risk of transplant recipient infection is unknown when the preservation solution culture is positive.

Methods

We developed a prediction model to evaluate the infection in kidney transplant recipients within microbial contaminated preservation solution. Univariate logistic regression was utilized to identify risk factors for infection. Both stepwise selection with Akaike information criterion (AIC) was used to identify variables for multivariate logistic regression. Selected variables were incorporated in the nomograms to predict the probability of infection for kidney transplant recipients with microbial contaminated preservation solution.

Results

Age, preoperative creatinine, ESKAPE, PCT, hemofiltration, and sirolimus had a strongest association with infection risk, and a nomogram was established with an AUC value of 0.72 (95% confidence interval, 0.64-0.80) and Brier index 0.20 (95% confidence interval, 0.18-0.23). Finally, we found that when the infection probability was between 20% and 80%, the model oriented antibiotic strategy should have higher net benefits than the default strategy using decision curve analysis.

Conclusion

Our study developed and validated a risk prediction model for evaluating the infection of microbial contaminated preservation solutions in kidney transplant recipients and demonstrated good net benefits when the total infection probability was between 20% and 80%.

Predictive value of perioperative procalcitonin, C reactive protein and high-sensitivity C reactive protein for the risk of postoperative complications after non-cardiac surgery in elderly patients: a nested case-control study

OBJECTIVE

Little is known about the correlation between perioperative concentrations of inflammatory biomarkers and postoperative complications. This study explored whether the plasma concentrations and perioperative changes of procalcitonin (PCT), C reactive protein (CRP) and high-sensitivity CRP (hsCRP) could predict the risk of postoperative morbidity in elderly patients undergoing elective non-cardiac surgery.

DESIGN

A nested case-control study.

SETTING

A tertiary hospital in China.

PARTICIPANTS

A total of 498 patients aged ≥65 years from a prospective cohort who underwent elective non-cardiac surgery between June 2020 and April 2021.

PRIMARY OUTCOME MEASURES

The primary outcomes were the efficacy of plasma concentrations of PCT, CRP and hsCRP in predicting the risk of Clavien-Dindo Classification (CDC) ≥grade 3 and major complications. The major complications included mortality, an intensive care unit stay length >24 hour, cardiovascular events, acute kidney injury, postoperative cognitive dysfunction and infections.

RESULTS

For major complications, the area under the curve (AUC) (95% CI) of PCT-24 hours, PCT change and PCT change rate were 0.750 (0.698 to 0.803), 0.740 (0.686 to 0.795) and 0.711 (0.651 to 0.771), respectively. The AUC (95% CI) of CRP-24 hours, CRP change, CRP change rate and hsCRP baseline were 0.835 (0.789 to 0.881), 0.818 (0.770 to 0.867), 0.691 (0.625 to 0.756) and 0.616 (0.554 to 0.678), respectively. For complications ≥CDC grade 3, the AUC (95% CI) of PCT-24 hours, PCT change and PCT change rate were 0.662 (0.543 to 0.780), 0.643 (0.514 to 0.772) and 0.627 (0.494 to 0.761), respectively. The AUC (95% CI) of CRP-24 hours and hsCRP baseline were 0.649 (0.527 to 0.771) and 0.639 (0.530 to 0.748), respectively.

CONCLUSIONS

PCT-24 hours, CRP-24 hours, the change of perioperative PCT and CRP were valuable predictors of major complications occurring within 30 days after non-cardiac surgery in the elderly.

TRIAL REGISTRATION NUMBER

China Clinical Trial Registry: ChiCTR1900026223.

Concurrent Change in Serum Cholinesterase Activity and Midregional-Proadrennomedullin Level Could Predict Patient Outcome following Liver Transplantation

Background: After liver transplantation (LTX), patients are susceptible to opportunistic infections resulting in reduced outcomes within the early post-transplantation period. The postoperative monitoring of LTX patients has gained much importance in recent years. However, reliable plasmatic markers predicting 90-day outcomes are still lacking. Methods: In the post hoc analysis of a prospective, observational study, butyrylcholinesterase (BChE), mid-regional proadrenomedullin (MR-proADM), as well as conventional inflammatory markers (procalcitonin, C-reactive protein) were evaluated in 93 patients at seven consecutive timepoints within the first 28 days following LTX. Results: Persistently reduced activity of BChE and elevated MR-proADM levels indicated reduced 90-day survival following LTX. Furthermore, reduced BChE and increased MR-proADM activity could indicate early post-transplantation bacterial infections, whereas conventional inflammatory biomarkers showed no diagnostic efficacy within the observation period. Conclusion: Concurrent assessment of BChE and MR-proADM activity might serve as a bedside diagnostic tool for early bacterial infections following liver transplantation. Thus, a combined utilization of the two biomarkers may be a useful tool in the risk evaluation of patients following liver transplantation.

The Airway Microbiota Signatures of Infection and Rejection in Lung Transplant Recipients

Infection and rejection are the two most common complications after lung transplantation (LT) and are associated with increased morbidity and mortality. We aimed to examine the association between the airway microbiota and infection and rejection in lung transplant recipients (LTRs). Here, we collected 181 sputum samples (event-free, n = 47; infection, n = 103; rejection, n = 31) from 59 LTRs, and performed 16S rRNA gene sequencing to analyze the airway microbiota. A significantly different airway microbiota was observed among event-free, infection and rejection recipients, including microbial diversity and community composition. Nineteen differential taxa were identified by linear discriminant analysis (LDA) effect size (LEfSe), with 6 bacterial genera, Actinomyces, Rothia, Abiotrophia, Neisseria, Prevotella, and Leptotrichia enriched in LTRs with rejection. Random forest analyses indicated that the combination of the 6 genera and procalcitonin (PCT) and T-lymphocyte levels showed area under the curve (AUC) values of 0.898, 0.919 and 0.895 to differentiate between event-free and infection recipients, event-free and rejection recipients, and infection and rejection recipients, respectively. In conclusion, our study compared the airway microbiota between LTRs with infection and acute rejection. The airway microbiota, especially combined with PCT and T-lymphocyte levels, showed satisfactory predictive efficiency in discriminating among clinically stable recipients and those with infection and acute rejection, suggesting that the airway microbiota can be a potential indicator to differentiate between infection and acute rejection after LT.

IMPORTANCE Survival after LT is limited compared with other solid organ transplantations mainly due to infection- and rejection-related complications. Differentiating infection from rejection is one of the most important challenges to face after LT. Recently, the airway microbiota has been reported to be associated with either infection or rejection of LTRs. However, fewer studies have investigated the relationship between airway microbiota together with infection and rejection of LTRs. Here, we conducted an airway microbial study of LTRs and analyzed the airway microbiota together with infection, acute rejection, and clinically stable recipients. We found different airway microbiota between infection and acute rejection and identify several genera associated with each outcome and constructed a model that incorporates airway microbiota and clinical parameters to predict outcome. This study highlighted that the airway microbiota was a potential indicator to differentiate between infection and acute rejection after LT.

Evaluation of procalcitonin (PCT) as a marker of infection in early post living donated liver transplant period

BACKGROUND AND AIM

Procalcitonin (PCT) has been increasingly used as a biomarker of bacterial infection and as a tool to guide antimicrobial therapy. Despite its increased use, data in patients with solid organ transplants are limited. The study aimed to assess the frequency of rising PCT associated with infectious complications in immunosuppressed living donated liver transplantation.

METHODS

A single-center, retrospective observational study. Preoperative patients' demographic data, operative, anesthetic data, and postoperative clinical course were analyzed post-liver transplant (LT) till discharge from the intensive care unit.

RESULTS

Sixty patients were classified according to the culture results' into a positive culture group & a negative one and then followed up the sepsis variables in each group. Total leukocyte count (TLC) was elevated in the positive culture group in comparison to the negative culture one and was statistically significant (P-value <0.05) till the fourth day postoperative. Procalcitonin was higher in the positive culture group than in the negative one on days 1, 3, and 5 postoperative and was statistically significant (P-value <0.05). The cutoff values in the receiver operating characteristic curve (ROC) with >90% specificity to infection post LT were PCT of ≥9 ng/ml and TLC of ≥17.3/mm3 on day one.

CONCLUSIONS

Following up PCT level on day one with TLC is essential and will help to detect sepsis and guide early antimicrobial initiation post-liver transplantation. Combined measurements of PCT and TLC with cutoff values of <9 ng/ml and < 17.3/mm³ respectively will help to exclude infections in 83.7% of patients, thus avoiding unnecessary usage of higher generations empiric antimicrobials.

Diagnostic Value of Procalcitonin in Transplant Patients Receiving Immunosuppressant Drugs: A Retrospective Electronic Medical Record-Based Analysis

OBJECTIVES

To evaluate concentrations of procalcitonin (PCT) in transplant recipients receiving immunosuppressive therapy compared with nonimmunosuppressed patients.

METHODS

We analyzed a data set of 9,500 inpatient encounters to compare levels of PCT and other biomarkers of infection (C-reactive protein [CRP], WBC count, and absolute neutrophil count [ANC]) between immunosuppressed and nonimmunosuppressed cohorts. We also assessed the correlation between PCT and clinical variables in immunosuppressed patients.

RESULTS

Patients receiving immunosuppressive drugs had significantly higher levels of maximal and minimal PCT compared with the nonimmunosuppressed patients (P < .0001 and P = .0019, respectively). However, CRP levels, WBC count, and ANC were significantly lower in immunosuppressed patients compared with the nonimmunosuppressed patients (P = .0003, P < .0019, and P = .0001, respectively).

CONCLUSIONS

Our results from real-world data demonstrated that PCT dynamics remain intact despite immunosuppressive therapy, in contrast to other biomarkers such as CRP, WBC, and ANC. In addition, higher PCT levels are associated with systemic infections and reflect disease severity.

Survival Outcome of Sepsis in Recipients of Solid Organ Transplant

Sepsis is a complex disease stemming from a dysregulated immune response toward an infectious agent. In transplantation, sepsis remains one of the leading causes of morbidity and mortality. Solid organ transplant recipients have impaired adaptive immunity due to immunosuppression required to prevent rejection. Immunosuppression has unintended consequences, such as increasing the risk of infections and sepsis. Due to its high morbidity and mortality, early detection of sepsis is paramount to start aggressive treatment. Several biomarkers or combination of biomarkers of sepsis have emerged in the last decade, but they are not dependable for early diagnosis or for outcome prognosis.

Sepsis in Immunocompromised Patients Without Human Immunodeficiency Virus

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

Serum Procalcitonin Correlates With Renal Function and Immune Components in Early-Stage Renal Transplant Recipients

BACKGROUND

In renal transplantation, monitoring procalcitonin (PCT) in the early post-transplant period can be a promising method for early tracking of infectious complications. However, the correlation between PCT and infection-related factors and immune components and renal function remains unclear.

PATIENTS AND METHODS

Between November 2017 and December 2018, 62 early-stage renal transplant recipients were selected, and 4 mL peripheral blood samples were collected to detect the changes of specific immune cells and cytokines. Our study was in compliance with the Helsinki Congress and the Declaration of Istanbul; no prisoners were used, and participants were neither paid nor coerced in our study.

RESULTS

According to serum PCT levels, recipients were divided into a high group (PCT ≥ 0.5 ng/mL) and a low group (PCT < 0.5 ng/mL). Compared with the low group, creatinine, cystatin C, urea, T helper type (Th) 22 cells, IL-22 + Th17 cells, interleukin (IL)-22, tumor necrosis factor alpha, and IL-17A increased while estimated glomerular filtration rate (eGFR) was decreased in the high group. In addition, PCT was significantly correlated with eGFR in the high group.

CONCLUSIONS

Serum PCT is related with renal function and seems to be associated with immune components in early-stage renal transplant recipients.

Re-evaluating Blood Markers as Predictors of Outcome in Multivisceral and Intestinal Transplantation

BACKGROUND

Multivisceral transplant (MVTx) and isolated intestinal transplant (ITx) are complex surgical procedures. The subsequent proinflammatory state in the immediate postoperative period makes interpretation of blood markers difficult.

METHOD

We aimed to establish the course of various blood markers after MVTx/ITx, and to evaluate their use as diagnostic markers of complications. This was a single center prospective cohort. We analyzed blood markers collected preoperatively, on alternate days for the first postoperative week, and then weekly for 4 weeks. This study was in compliance with The Declaration of Helsinki.

RESULTS

Over a 16-month period (July 2017-October 2018), 20 subjects aged 2 to 67 years with a median age of 24.5 years received MVTx/ITx. Twelve recipients (60%) had an infection. Neutrophil lymphocyte count ratio (NLCR) was higher than established upper limits of normal, regardless of infection status. NLCR and white blood cell count were useful to identify infected MVTx/ITx recipients, with P values <.05 for 2 and 1 of 7 time points post transplant, respectively. Higher preoperative eosinophil% predicted future acute cellular rejection (P value .023).

CONCLUSIONS

This is the first study to extensively track the course of blood markers post MVTx/ITx and identified NLCR and white blood cell count as potential diagnostic blood markers of infection.

Antimicrobial stewardship in transplant patients

PURPOSE OF REVIEW

To provide an update on the current landscape of antimicrobial stewardship in solid organ transplant (SOT) recipients.

RECENT FINDINGS

Constructing personalized antimicrobial prescribing approaches to avoid untoward consequences of antimicrobials while improving outcomes is an emerging and critical aspect of transplant medicine. Stewardship activities encompassing the specialized interests of transplant patients and programs are evolving. New literature evaluating strategies to optimize antimicrobial agent selection, dosing, and duration have been published. Additionally, consensus guidance for certain infectious clinical syndromes is available and should inform institutional clinical practice guidelines. Novel metrics for stewardship-related outcomes in transplantation are desperately needed. Though exciting new molecular diagnostic technologies will likely be pivotal in the care of immunocompromised patients, optimal clinical adaptation and appropriate integration remains unclear. Important studies understanding the behaviors influencing antimicrobial prescribing in organizational transplant cultures are needed to optimize interventions.

SUMMARY

Consequences of antimicrobial use, such as Clostridiodes difficile and infections with multidrug-resistant organisms disproportionately affect SOT recipients and are associated with poor allograft and patient outcomes. Application of ASP interventions tailored to SOT recipients is recommended though further studies are needed to provide guidance for best practice.

Risk factors and etiology of repeat infection in kidney transplant recipients

Kidney transplantation (KT) is the best therapy available for patients with end-stage renal disease, but postoperative infections are a significant cause of mortality.In this retrospective study the frequency, risk factors, causative pathogens, and clinical manifestations of infection in KT recipients from Beijing Chao-Yang Hospital, Capital Medical University were investigated. Ninety-seven KT recipients who were hospitalized with infection between January 2010 and December 2016 were included. Clinical characteristics, surgery details, laboratory results, and etiology were compared in patients who developed single infection and patients who developed repeated infection (2 or more) after KT.A total of 161 infections were adequately documented in a total of 97 patients, of which 57 patients (58.8%) had 1 infection, 24 (24.7%) had 2, 11 (11.3%) had 3; 3 (3.1%) had 4, and 2 (2.1%) had 5 or more. The most common infection site was the urinary tract (90 infections; 56%), both overall and in the repeated infection group. The most frequently isolated pathogen was Pseudomonas aeruginosa. In the repeated infection patients, in most cases of P. aeruginosa infection (54%) it was cultured from urine. For first infections, a time between KT and infection of ≤ 21 days (area under receiver operating characteristic curve [AUC] 0.636) and a tacrolimus level ≥ 8 ng/mL (AUC 0.663) independently predicted repeat infection. The combination of these two predictive factors yielded an AUC of 0.716, which did not differ statistically significantly from either predictor alone.With regard to first infections after KT, a time between KT and infection of ≤ 21 days, and a tacrolimus level ≥ 8 ng/mL each independently predicted repeated infection in KT recipients.

Primary graft dysfunction after heart transplantation: a thorn amongst the roses

Primary graft dysfunction (PGD) remains the leading cause of early mortality post-heart transplantation. Despite improvements in mechanical circulatory support and critical care measures, the rate of PGD remains significant. A recent consensus statement by the International Society of Heart and Lung Transplantation (ISHLT) has formulated a definition for PGD. Five years on, we look at current concepts and future directions of PGD in the current era of transplantation.

Pneumonia in solid organ transplantation: Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These guidelines from the AST Infectious Diseases Community of Practice review the diagnosis and management of pneumonia in the post-transplant period. Clinical presentations and differential diagnosis for pneumonia in the solid organ transplant recipient are reviewed. A two-tier approach is proposed based on the net state of immunosuppression and the severity of presentation. With a lower risk of opportunistic, hospital-acquired, or exposure-specific pathogens and a non-severe presentation, empirical therapy may be initiated under close clinical observation. In all other patients, or those not responding to the initial therapy, a more aggressive diagnostic approach including sampling of tissue for microbiological and pathological testing is warranted. Given the broad range of potential pathogens, a microbiological diagnosis is often key for optimal care. Given the limited literature comparatively evaluating diagnostic approaches to pneumonia in the solid organ transplant recipient, much of the proposed diagnostic algorithm reflects clinical experience rather than evidence-based data. It should serve as a template which may be modified according to local needs. The same holds true for the suggested empiric therapies, which need to be adapted to the local resistance patterns. Further study is needed to comparatively evaluate diagnostic and empiric treatment strategies in SOT recipients.

Procalcitonin and Liver Disease: A Literature Review

Procalcitonin (PCT) is a widely used biomarker for the diagnosis of bacterial infections. It is produced by various organs and the liver is considered to be the most important site of production. Severe liver dysfunction has been shown to influence PCT levels. Patients with no sources of infection who have liver disease are observed to have increased serum levels of PCT, thereby reducing the diagnostic utility and value within this particular patient subset. Here, we have summarized the relationship between PCT and liver disease, including liver cirrhosis, liver failure, and liver transplantation.

The Importance of Serological Procalcitonin Levels After Autologous Microsurgical Transplantation

INTRODUCTION

Published data on procalcitonin (PCT) levels after microsurgical interventions are very scarce, although infection within these patients is not only associated with severe morbidity but also significantly higher mortality rates.

MATERIAL AND METHODS

Retrospective study on 20 patients, who were operated on by a single experienced plastic and reconstructive surgeon within one year (June 2017-June 2018). The authors included all patients, who received microvascular transplants for reconstruction of soft tissue defects. Furthermore, age above 18 years and appropriate documentation allowing sufficient data collection were defined as inclusion criteria. The authors excluded all patients with perioperative systemic inflammation and transplant loss, as our aim was to solely determine and evaluate potential alterations of serological PCT levels after microsurgical interventions.

RESULTS

The PCT cutoff level to differentiate physiological and pathological levels was defined as 0.1 μg/L. There was no detectable increase in procalcitonin in all of our 20 patients, for whom the authors performed microvascular transplantation to reconstruct soft tissue defects.

CONCLUSION

Serological PCT levels remain stable after the considered surgical interventions and therefore PCT levels might be utilized to identify systemic inflammation, thus helping to reduce severe complications by early individualized antiinfective treatment strategies.

Impacts and Challenges of Advanced Diagnostic Assays for Transplant Infectious Diseases

The advanced technologies described in this chapter should allow for full inventories to be made of bacterial genes, their time- and place-dependent expression, and the resulting proteins as well as their outcome metabolites. The evolution of these molecular technologies will continue, not only in the microbial pathogens but also in the context of host-pathogen interactions targeting human genomics and transcriptomics. Their performance characteristics and limitations must be clearly understood by both laboratory personnel and clinicians to ensure proper utilization and interpretation.

Strategies for Antimicrobial Stewardship in Solid Organ Transplant Recipients

Complications of antimicrobial therapy, such as multidrug-resistant organisms and Clostridium difficile, commonly affect solid-organ transplant recipients and have been associated with graft loss and mortality. Although opportunities are abundant, antimicrobial stewardship practices guiding appropriate therapy have been infrequently reported in transplant patients. A patient-centered, multidisciplinary structure, using established antimicrobial optimization principles, is needed to create nuanced approaches to protect patients and antimicrobials and improve outcomes.

Pretransplant serum procalcitonin level for prediction of early post-transplant sepsis in living donor liver transplantation

AIM

Infection is a frequent cause of in-hospital mortality after liver transplantation (LT). Elimination of possible risks in the pretransplant period, early diagnosis of post-transplant sepsis, and prompt treatment with antimicrobial agents are important. The objectives of this study were to analyze the impact of early post-transplant sepsis on outcomes and to clarify the value of predictive factors for early post-transplant sepsis.

METHODS

The study included 136 patients who underwent initial living donor LT (LDLT) at our institute between April 2009 and December 2016. Sepsis was defined using the third international consensus criteria. The results of biochemical tests at the introduction of anesthesia before LDLT were collected for pretransplant evaluation.

RESULTS

Post-transplant sepsis was found in 37 patients (27.2%). More patients had a pre-transplant serum procalcitonin (PCT) level >0.5 ng/mL in the sepsis group than in the non-sepsis group (11 [29.7%] vs 10 [10.1%]; P = 0.007). The 1-year survival rate in the sepsis group was significantly lower than in the non-sepsis group (53.8% vs 87.2%; P < 0.001). Multivariate analysis identified pretransplant serum PCT >0.5 ng/mL (odds ratio, 3.8; 95% confidence interval, 1.3-10.9; P = 0.01) as the only independent risk factor for post-transplant sepsis.

CONCLUSIONS

Survival of patients with early post-transplant sepsis was poor and the incidence of sepsis was associated with the pretransplant serum PCT level. Re-evaluation of the general condition and rescheduling of LT should be considered in a patient with pretransplant serum PCT >0.5 ng/mL.

Predictive Value of Procalcitonin for Infection and Survival in Adult Cardiogenic Shock Patients Treated with Extracorporeal Membrane Oxygenation

Procalcitonin (PCT) is a predictive marker for the occurrence of bacterial infection and the decision to terminate antibiotic treatment in critically ill patients. An unusual increase in PCT, regardless of infection, has been observed during extracorporeal membrane oxygenation (ECMO) support. We evaluated trends and the predictive value of PCT levels in adult cardiogenic shock during treatment with ECMO. We reviewed the clinical records of 38 adult cardiogenic shock patients undergoing veno-arterial ECMO support between January 2014 and December 2016. The exclusion criteria were age <18 years, pre-ECMO infection, and less than 48 hours of support. The mean patient age was 56.7±14.7 years and 12 (31.6%) patients were female. The mean duration of ECMO support was 9.0±7.6 days. The rates of successful ECMO weaning and survival to discharge were 55.3% (n=21) and 52.6% (n=20), respectively. There were 17 nosocomial infections in 16 (42.1%) patients. Peak PCT levels (mean 25.6±9.4 ng/mL) were reached within 48 hours after initiation of ECMO support and decreased to ≤5 ng/mL within one week. The change in PCT levels was not useful in predicting the occurrence of new nosocomial infections during the ECMO run. However, a PCT level >10 ng/mL during the first week of ECMO support was significantly associated with mortality (p<0.01). The change in PCT level was not useful in predicting new infection during ECMO support. However, higher PCT levels within the first week of the ECMO run are associated with significantly higher mortality.

Feasibility and applicability of antimicrobial stewardship in immunocompromised patients

PURPOSE OF REVIEW

Antimicrobial stewardship is the primary intervention in the battle against antimicrobial resistance, but clinicians do not always apply many key antimicrobial stewardship principles to patients with significant immune defects due to lack of data and fear of bad outcomes. We review evidence regarding the application of stewardship principles to immunocompromised patients, with a focus on solid organ and hematopoietic stem cell transplant recipients.

RECENT FINDINGS

Antimicrobial stewardship programs (ASPs), targeting immunocompromised patient populations such as oncology and transplant, are gaining traction. Emerging literature suggests that several stewardship interventions can be adapted to immunocompromised hosts and improve antimicrobial utilization, but data supporting improved outcomes is very limited.

SUMMARY

The application of antimicrobial stewardship principles to immunocompromised patients is feasible, necessary, and urgent. As antimicrobial stewardship programs gain momentum across a diverse range of healthcare settings more immunocompromised patients will fall under their purview. It is imperative that centers applying antimicrobial stewardship principles share their experience and establish collaborative research efforts to advance our knowledge base in applying antimicrobial stewardship initiatives to immunocompromised host populations, both in terms of programmatic success and patient outcomes.

Clostridium difficile infection in solid organ transplant recipients

PURPOSE OF REVIEW

Clostridium difficile infection (CDI) is a major healthcare-associated infection that causes significant morbidity and an economic impact in the United States. In this review, we provide an overview of Clostridium difficile infection in solid organ transplant recipients with an emphasis on recent literature.

RECENT FINDINGS

C. difficile in solid organ transplant population has unique risk factors. Fecal microbiota transplantation has shown favorable results in treatment of recurrent C. difficile in this population. Preliminary data from animal studies suggests excellent efficacy with immunization against C. difficile toxins.

SUMMARY

Over the last decade, number of individuals receiving solid organ transplants has increased exponentially making peri-transplant complications a common occurrence.C. difficile is a frequent cause of morbidity in solid organ transplant recipients. Early and accurate diagnosis of C. difficile requires a stepwise approach. Differentiating between asymptomatic carriage and infection is a diagnostic challenge. Microbial diversity is inversely proportional to risk of C. difficile infection. Antimicrobial stewardship programs help to retain microbial diversity in individuals susceptible to CDI. Recurrent or relapsing C. difficile infection require fecal microbiota transplantation for definitive cure.

Procalcitonin for infections in the first week after pediatric liver transplantation

Background

Procalcitonin (PCT) has become a commonly used serum inflammatory marker. Our aim was to describe the kinetics and usefulness of serial post-operative PCT measurements to detect bacterial infection in a cohort of children immediately after pediatric liver transplantation (pLT).

Methods

We performed a retrospective chart review of a cohort of pLT recipients with serial serum PCT measurements in the first week following pLT. The presence of infection was determined on clinical and biological parameters. Normal PCT was defined as < 0.5 (ng/ml).

Results

Thirty-nine patients underwent 41 pLT. PCT was measured daily during the first week post pLT. Values first increased following surgery and then decreased, nearing 0.5 ng/ml at day seven. Peak PCT reached a median of 5.61 ng/ml (IQR 3.83-10.8). Seventeen patients were considered to have an infection. There was no significant difference in daily PCT or peak PCT between infected and non infected patients during the first post-operative week. AUC of ROC curve for PCT during first week was never higher than 0.6.

Conclusions

We conclude that serial PCT measurements during the first week after pLT is not useful to identify patients with bacterial infections. Rather, we propose that serum PCT may be useful after the first week post pLT.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-017-2234-y) contains supplementary material, which is available to authorized users.