A 2010 working formulation for the standardization of definitions of infections in cardiothoracic transplant recipients

Donor-derived cell-free DNA accurately detects acute rejection in lung transplant patients, a multicenter cohort study

BACKGROUND

Acute rejection, which includes antibody-mediated rejection and acute cellular rejection, is a risk factor for lung allograft loss. Lung transplant patients often undergo surveillance transbronchial biopsies to detect and treat acute rejection before irreversible chronic rejection develops. Limitations of this approach include its invasiveness and high interobserver variability. We tested the performance of percent donor-derived cell-free DNA (%ddcfDNA), a non-invasive blood test, to detect acute rejection.

METHODS

This multicenter cohort study monitored 148 lung transplant subjects over a median of 19.6 months. We collected serial plasma samples contemporaneously with TBBx to measure %ddcfDNA. Clinical data was collected to adjudicate for acute rejection. The primary analysis consisted of computing the area-under-the-receiver-operating-characteristic-curve of %ddcfDNA to detect acute rejection. Secondary analysis determined %ddcfDNA rule-out thresholds for acute rejection.

RESULTS

ddcfDNA levels were high after transplant surgery and decayed logarithmically. With acute rejection, ddcfDNA levels rose six-fold higher than controls. ddcfDNA levels also correlated with severity of lung function decline and histological grading of rejection. %ddcfDNA area-under-the-receiver-operating-characteristic-curve for acute rejection, AMR, and ACR were 0.89, 0.93, and 0.83, respectively. ddcfDNA levels of <0.5% and <1.0% showed a negative predictive value of 96% and 90% for acute rejection, respectively. Histopathology detected one-third of episodes with ddcfDNA levels ≥1.0%, even though >90% of these events were coincident to clinical complications missed by histopathology.

CONCLUSIONS

This study demonstrates that %ddcfDNA reliably detects acute rejection and other clinical complications potentially missed by histopathology, lending support to its use as a non-invasive marker of allograft injury.

Divergent airway microbiomes in lung transplant recipients with or without pulmonary infection

BACKGROUND

Lung transplant (LTx) recipients are at increased risk for airway infections, but the cause of infection is often difficult to establish with traditional culture-based techniques. The objectives of the study was to compare the airway microbiome in LTx patients with and without ongoing airway infection and identify differences in their microbiome composition.

METHODS

LTx recipients were prospectively followed with bronchoalveolar lavage (BAL) during the first year after transplantation. The likelihood of airway infection at the time of sampling was graded based on clinical criteria and BAL cultures, and BAL fluid levels of the inflammatory markers heparin-binding protein (HBP), IL-1β and IL-8 were determined with ELISA. The bacterial microbiome of the samples were analysed with 16S rDNA sequencing and characterized based on richness and evenness. The distance in microbiome composition between samples were determined using Bray-Curtis and weighted and unweighted UniFrac.

RESULTS

A total of 46 samples from 22 patients were included in the study. Samples collected during infection and samples with high levels of inflammation were characterized by loss of bacterial diversity and a significantly different species composition. Burkholderia, Corynebacterium and Staphylococcus were enriched during infection and inflammation, whereas anaerobes and normal oropharyngeal flora were less abundant. The most common findings in BAL cultures, including Pseudomonas aeruginosa, were not enriched during infection.

CONCLUSION

This study gives important insights into the dynamics of the airway microbiome of LTx recipients, and suggests that lung infections are associated with a disruption in the homeostasis of the microbiome.

Infections Within the First Month After Pediatric Lung Transplantation: Epidemiology and Impact on Outcomes

BACKGROUND

Despite successes in lung transplantation, with infection as the leading cause of death in the first year following lung transplantation, there remains a lag in survival compared with other solid organ transplants. Infections that occur early after transplantation may impact short- and long-term outcomes in pediatric lung transplant recipients (LTRs).

METHODS

We performed a retrospective review of pediatric LTRs at a large quaternary-care hospital from January 2009 to March 2016 to evaluate both epidemiologic features of infection in the first 30 days post-transplantation and mortality outcomes. The 30 days were divided into early (0-7 days) and late (8-30 days) periods.

RESULTS

Among the 98 LTRs, there were 51 episodes of infections. Cystic fibrosis (CF) was associated with early bacterial infections (P = .004) while non-CF was associated with late viral (P = .02) infections. Infection after transplantation was associated with worse survival by Kaplan-Meier analysis (P value log rank test = .007). Viral infection in the late period was significantly associated with 3-year mortality after multivariable analysis (P = .02).

CONCLUSIONS

Infections in pediatric LTRs were frequent in the first 30 days after transplant, despite perioperative antimicrobial coverage. The association of 3-year mortality with late viral infections suggests a possible important role in post-transplant lung physiology and graft function. Understanding the epidemiology of early post-lung transplant infections can help guide post-operative management and interventions to reduce their incidence and the early- and long-term impact in this population.

Outcomes Of Non-Cystic Fibrosis Related Bronchiectasis Post Lung Transplantation

BACKGROUND

Lung transplantation is a recognised treatment for end-stage lung disease due to bronchiectasis. Non-CF bronchiectasis and CF are often combined into one cohort, however outcomes for non-CF bronchiectasis patients varies between centres, and in comparison to those for CF.

AIMS

To compare lung transplantation mortality and morbidity of bronchiectasis (non-CF) patients to those with CF and other indications.

METHODS

Retrospective analysis of patients undergoing lung transplantation between 01 January 2008-31 December 2013. Time to and cause of lung allograft loss was censored on 01 April 2018. A case-note review was conducted on a sub-group of 78 patients, to analyse hospital admissions as a marker of morbidity.

RESULTS

341 patients underwent lung transplantation, 22 (6%) had bronchiectasis compared to 69 (20%) with CF. The 5-year survival for the bronchiectasis group was 32%, compared to CF 69%, obstructive lung disease (OLD) 64%, pulmonary hypertension 62% and ILD 55% (p = 0.008). Lung allograft loss due to CLAD with predominant infection was significantly higher in the bronchiectasis group at 2 years. The rate of acute admissions was 2.24 higher in the bronchiectasis group when compared to OLD (p = 0.01). Patients with bronchiectasis spent 45.81 days in hospital per person year after transplantation compared with 18.21 days for CF.

CONCLUSIONS

Bronchiectasis patients in this study had a lower 5-year survival and poorer outcomes in comparison to other indications including CF. Bronchiectasis should be considered a separate entity to CF in survival analysis. This article is protected by copyright. All rights reserved.

Risk of Lung Allograft Dysfunction Associated With Aspergillus Infection

We sought to determine whether invasive aspergillosis (IA) during the first year after lung transplantation increased the risk of chronic lung allograft dysfunction (CLAD).

Methods

We retrospectively reviewed the records of 191 patients who underwent lung transplantation at our institution between January 2013 and December 2017. Screening for Aspergillus was with bronchial aspirates, bronchoalveolar lavage if indicated or during surveillance bronchoscopy, radiography, and computed tomography. We used Fine and Gray multivariable regression to identify potential risk factors for CLAD.

Results

During the first posttransplant year, 72 patients had at least 1 deep-airway sample positive for Aspergillus; 63 were classified as having IA and were included in the study. Median number of endoscopies per patient during the first year was 9 (range, 1-44). Median time from transplantation to first Aspergillus-positive sample was 121 d. Bronchial aspirate samples and bronchoalveolar lavage fluid were positive in 71 and 44 patients, respectively. Aspergillus fumigatus (n = 36, 50%) predominated; bacterial samples were also positive in 22 (31%) patients. IA within 4 mo after transplantation was independently associated with CLAD development (subdistribution hazard ratio, 3.75; 95% confidence interval [CI], 1.61-8.73; P < 0.01) by regression analysis. Survival at 3 and 5 y conditional on 1-y CLAD-free survival was 37% (95% CI, 24%-58%), and 24% (95% CI, 11%-52%) in the IA <4 mo group compared to 65% (95% CI, 57%-73%) and 54% (95% CI, 43%-66%) in the non-IA group and to 69% (95% CI, 58%-83%) and 54% (95% CI, 35%-82%) in the IA ≥4 mo group, respectively (P < 0.01, logrank test).

Conclusions

Our evaluation of de novo IA showed that this infection was most strongly associated with CLAD when found within 4 mo after transplantation.

Late Onset Invasive Pulmonary Aspergillosis in Lung Transplant Recipients in the Setting of a Targeted Prophylaxis/Preemptive Antifungal Therapy Strategy

BACKGROUND

Invasive pulmonary aspergillosis (IPA) is a significant cause of morbidity and mortality in lung transplant recipients (LTRs). It is unclear how a targeted prophylaxis/ preemptive antifungal therapy strategy impacts the incidence of IPA beyond the first-year posttransplant.

METHODS

This is a retrospective cohort of LTRs from January 2010 to December 2014. We included all LTRs who survived beyond the first year and followed them until death or 4 years postoperatively. Incidence of probable/proven IPA and Aspergillus colonization were assessed as per International Society for Heart and Lung Transplantation (ISHLT) criteria. Patients with risk factors, positive Aspergillus cultures, or galactomannan (GM) received targeted prophylaxis/preemptive therapy within the first-year posttransplant.

RESULTS

During the study period, 350 consecutive LTRs underwent 1078 bronchoscopies. Positive bronchoalveolar lavage for GM or Aspergillus cultures was reported for 15% (52/350) of LTRs between 2 and 4 years after transplantation. Among them, the median time to positive Aspergillus culture or GM positivity was 703 days (interquartile range, 529-754 d). The incidence rate of IPA and Aspergillus colonization was 30 of 1000 patient-y, and 63 of 1000 patient-y, respectively. The mortality rate was significantly higher in patients with IPA than without IPA (107/1000 patient-years versus 18/1000 patient-years; P < 0.0001). Rate of first-year colonization and IPA was 33% and 9%, respectively. Among the 201 patients who had a negative bronchoscopy during the first year posttransplant, only 6 (3%) developed IPA during the follow-up.

CONCLUSIONS

A targeted prophylaxis/preemptive therapy strategy within the first-year posttransplant resulted in 4% incidence of IPA at 4-years after transplantation. However, IPA was associated with higher mortality.

CYP51A polymorphisms of Aspergillus fumigatus in lung transplant recipients: Prevalence, correlation with phenotype, and impact on outcomes

Azole resistance in Aspergillus fumigatus is increasing worldwide and can affect prognosis. It is mostly mediated by cytochrome P51 (CYP51) mutations. In lung transplant recipients (LTR), little is known regarding the prevalence and clinical impact of CYP51 mutations. One hundred thirty-one consecutive A. fumigatus isolates from 103 patients were subjected to CYP51A genotyping through PCR and sequencing. Antifungal susceptibility testing was performed using the Sensititre YeastOne YO-9© broth microdilution technique. Correlations between genotype, phenotype, clinical manifestations of Aspergillus infection, and clinical outcomes were made. Thirty-four (26%) isolates harbored mutations of CYP51A; N248K (n = 14) and A9T (n = 12) were the most frequent. Three isolates displayed multiple point mutations. No significant influences of mutational status were identified regarding azole MICs, the clinical presentation of Aspergillus disease, 1-year all-cause mortality, and clinical outcomes of invasive forms. In the specific context of lung transplant recipients, non-hotspot CYP51A-mutated isolates are regularly encountered; this does not result in major clinical consequences or therapeutic challenges.

LAY SUMMARY

In 131 isolates of Aspergillus fumigatus isolates originating from 103 lung transplant recipients, the CYP51A polymorphism rate was 26%, mostly represented by N248K and A9T mutations. These mutations, however, did not significantly impact azoles minimal inhibitory concentrations or clinical outcomes.

Predictive Value of Immune Cell Functional Assay for Non-Cytomegalovirus Infection in Lung Transplant Recipients: A Multicenter Prospective Observational Study

INTRODUCTION

Immune cell functional assay (ImmuKnow®) is a non-invasive method that measures the state of cellular immunity in immunosuppressed patients. We studied the prognostic value of the assay for predicting non-cytomegalovirus (CMV) infections in lung transplant recipients.

METHODS

A multicenter prospective observational study of 92 patients followed up from 6 to 12 months after transplantation was performed. Immune cell functional assay was carried out at 6, 8, 10, and 12 months.

RESULTS

Twenty-three patients (25%) developed 29 non-CMV infections between 6 and 12 months post-transplant. At 6 months, the immune response was moderate (ATP 225-525ng/mL) in 14 (15.2%) patients and low (ATP<225ng/mL) in 78 (84.8%); no patients had a strong response (ATP≥525ng/mL). Only 1 of 14 (7.1%) patients with a moderate response developed non-CMV infection in the following 6 months compared with 22 of 78 (28.2%) patients with low response, indicating sensitivity of 95.7%, specificity of 18.8%, positive predictive value (PPV) of 28.2%, and negative predictive value (NPV) of 92.9% (AUC 0.64; p=0.043). Similar acute rejection rates were recorded in patients with mean ATP≥225 vs. <225ng/mL during the study period (7.1% vs. 9.1%, p=0.81).

CONCLUSION

Although ImmuKnow® does not seem useful to predict non-CMV infection, it could identify patients with a very low risk and help us define a target for an optimal immunosuppression.

Scedosporium apiospermum and Lomentospora prolificans in lung transplant patients - A single center experience over 24 years

INTRODUCTION

Scedosporium apiospermum and Lomentospora prolificans (Scedosporium/Lomentospora) species are emerging, multi-resistant pathogens that cause life-threatening illnesses among lung transplant (LTx) recipients. The current epidemiology and management in LTx are unknown.

METHODS

We performed a retrospective single center audit of all sputum/bronchoscopy samples for Scedosporium/Lomentospora species in LTx patients over a 24-year period (1995-2019). Patients were diagnosed as colonized or with invasive fungal disease.

RESULTS

From a cohort of 962 LTx recipients, 30 patients (3.1%) cultured Scedosporium/Lomentospora (1.2%, 1.9%, respectively). There were no isolates from 1995 to 2013, with multiple yearly isolates thereafter. Nineteen (63%) cases were classified as IFD, and 11 (37%) as colonization. The median time to first culture from transplantation was 929 days (Interquartile-range [IQR] 263-2960). Most patients (63%) had received antifungals prior to the first positive culture of Scedosporium/Lomentospora for other fungal infection. The most common antifungal used for treatment of Scedosporium/Lomentospora was posaconazole (n = 16; 53%). Median duration of therapy was 364 days (IQR 164-616). Treatment was associated with improved lung function over 6 months (median FEV1 increased from 1.3L[IQR 0.9-1.8L] to 1.8L[IQR 1.1-2.3] P = .05). Six patients cultured Scedosporium/Lomentospora prior to transplantation, and no survival disadvantage was seen as compared to our whole LTx cohort (P = .8).

CONCLUSION

Our single center 24-year experience suggests that the incidence of Scedosporium/Lomentospora is increasing. Scedosporium/Lomentospora is typically isolated several years after LTx, and requires prolonged anti-fungal treatment that is usually associated with improved in lung function. Culture of Scedosporium/Lomentospora prior to LTx did not pose a survival disadvantage. Further surveillance is required to fully characterize implications of these organisms for LTx recipients.

Distribution and resistance of pathogens in infected patients within 1 year after heart transplantation

BACKGROUND

Infection is a major cause of morbidity and mortality after heart transplantation (HT). However, there have been few data on clinical manifestation, distribution, and resistance of pathogens in the infected population of heart transplant recipients.

METHODS

We conducted a single-center retrospective study on patients who underwent HT in Wuhan Union Hospital from August 3, 2012 to July 30, 2016. Risk factors for infections that occur within 1 year after HT were investigated by multivariable logistic regression analysis.

RESULTS

Among 299 patients, 147 patients (49.2%) confirmed infection. The most common site of infection was the respiratory system. A total of 259 pathogens were detected in 147 patients (49.2%) with infection after HT. In all, 64 multidrug-resistant (MDR) bacteria were detected in infected patients within 1 year after HT, the most common MDR bacteria were extended-spectrum β-lactamases (ESBL) Klebsiella pneumonia and methicillin-resistant Staphylococcus aureus (MRSA). In the multivariable model, diabetes (OR 3.273 [95%CI, 1.748-6.130], and p < .001) and antibiotics treatment within 1 month before transplant (OR 1.860 [95%CI, 1.093-3.166], and p = .022) were significantly associated with infections within 1 year after HT.

CONCLUSIONS

This study confirmed the high rate of infections within 1 year after HT. Diabetes and antibiotics treatment within 1 month before transplant were independent risk factors for infections within 1 year after HT.

Effects of Multidrug-resistant Bacteria in Donor Lower Respiratory Tract on Early Posttransplant Pneumonia in Lung Transplant Recipients Without Pretransplant Infection

BACKGROUND

Multidrug-resistant (MDR) bacteria in the lower respiratory tracts of allografts may be risk factors for early posttransplant pneumonia (PTP) that causes detrimental outcomes in lung transplant recipients (LTRs). We evaluated the effects of immediate changes in MDR bacteria in allografts on early PTP and mortality rates in LTRs.

METHODS

We reviewed 90 adult bilateral LTRs without pretransplant infections who underwent lung transplantation between October 2012 and May 2018. Quantitative cultures were performed with the bronchoalveolar lavage fluids of the allografts preanastomosis and within 3 days posttransplant. The International Society for Heart and Lung Transplantation consensus defines early PTP as pneumonia acquired within 30 days posttransplant and not associated with acute rejection.

RESULTS

MDR Acinetobacter baumannii (11/34, 32.4%) and Staphylococcus aureus (9/34, 26.5%) were identified in 24.4% (22/90) of the preanastomosis allografts. Four LTRs had the same MDR bacteria in allografts preanastomosis and posttransplant. Allograft MDR bacteria disappeared in 50% of the LTRs within 3 days posttransplant. Early PTP and all-cause in-hospital mortality rates were not different between LTRs with and without preanastomosis MDR bacteria (P = 0.75 and 0.93, respectively). MDR bacteria ≥10 CFU/mL in the lungs within 3 days posttransplant was associated with early PTP (odds ratio, 5.8; 95% confidence interval, 1.3-27.0; P = 0.03).

CONCLUSIONS

High levels of preexisting MDR bacteria in allografts did not increase early PTP and mortality rates in LTRs. Despite the small and highly selective study population, lung allografts with MDR bacteria may be safely transplanted with appropriate posttransplant antibiotic therapy.

Azithromycin Partially Mitigates Dysregulated Repair of Lung Allograft Small Airway Epithelium

BACKGROUND

Dysregulated airway epithelial repair following injury is a proposed mechanism driving posttransplant bronchiolitis obliterans (BO), and its clinical correlate bronchiolitis obliterans syndrome (BOS). This study compared gene and cellular characteristics of injury and repair in large (LAEC) and small (SAEC) airway epithelial cells of transplant patients.

METHODS

Subjects were recruited at the time of routine bronchoscopy posttransplantation and included patients with and without BOS. Airway epithelial cells were obtained from bronchial and bronchiolar brushing performed under radiological guidance from these patients. In addition, bronchial brushings were also obtained from healthy control subjects comprising of adolescents admitted for elective surgery for nonrespiratory-related conditions. Primary cultures were established, monolayers wounded, and repair assessed (±) azithromycin (1 µg/mL). In addition, proliferative capacity as well as markers of injury and dysregulated repair were also assessed.

RESULTS

SAEC had a significantly dysregulated repair process postinjury, despite having a higher proliferative capacity than large airway epithelial cells. Addition of azithromycin significantly induced repair in these cells; however, full restitution was not achieved. Expression of several genes associated with epithelial barrier repair (matrix metalloproteinase 7, matrix metalloproteinase 3, the integrins β6 and β8, and β-catenin) were significantly different in epithelial cells obtained from patients with BOS compared to transplant patients without BOS and controls, suggesting an intrinsic defect.

CONCLUSIONS

Chronic airway injury and dysregulated repair programs are evident in airway epithelium obtained from patients with BOS, particularly with SAEC. We also show that azithromycin partially mitigates this pathology.

Community-acquired Respiratory Viruses Are a Risk Factor for Chronic Lung Allograft Dysfunction

Background

The relationship between community-acquired respiratory viruses (CARVs) and chronic lung allograft dysfunction (CLAD) in lung transplant recipients is still controversial.

Methods

We performed a prospective cohort study (2009–2014) in all consecutive adult patients (≥18 years) undergoing lung transplantation in the Hospital Universitari Vall d’Hebron (Barcelona, Spain). We systematically collected nasopharyngeal swabs from asymptomatic patients during seasonal changes, from patients with upper respiratory tract infectious disease, lower respiratory tract infectious disease (LRTID), or acute rejection. Nasopharyngeal swabs were analyzed by multiplex polymerase chain reaction. Primary outcome was to evaluate the potential association of CARVs and development of CLAD. Time-dependent Cox regression models were performed to identify the independent risk factors for CLAD.

Results

Overall, 98 patients (67 bilateral lung transplant recipients; 63.3% male; mean age, 49.9 years) were included. Mean postoperative follow-up was 3.4 years (interquartile range [IQR], 2.5–4.0 years). Thirty-eight lung transplant recipients (38.8%) developed CLAD, in a median time of 20.4 months (IQR, 12–30.4 months). In time-controlled multivariate analysis, CARV-LRTID (hazard ratio [HR], 3.00 [95% confidence interval {CI}, 1.52–5.91]; P = .002), acute rejection (HR, 2.97 [95% CI, 1.51–5.83]; P = .002), and cytomegalovirus pneumonitis (HR, 3.76 [95% CI, 1.23–11.49]; P = .02) were independent risk factors associated with developing CLAD.

Conclusions

Lung transplant recipients with CARVs in the lower respiratory tract are at increased risk to develop CLAD.

Incidence, management and outcome of respiratory syncytial virus infection in adult lung transplant recipients: a 9-year retrospective multicentre study

OBJECTIVES

To analyse functional outcome parameters according to antimicrobial treatments after respiratory syncytial virus (RSV)-confirmed infection in adult lung transplant recipients.

METHODS

A 9-year retrospective multicentre cohort study (2011-19) included adult lung transplant recipients with RSV-confirmed infection. The first endpoint determined new allograft dysfunction (acute graft rejection and chronic lung allograft dysfunction (CLAD)) 3 months after infection. Then baseline and 3 months' postinfection forced expiratory volume in 1 second (FEV₁) values were compared according to antimicrobial treatment. Univariate logistic regression analysis was performed.

RESULTS

RSV infection was confirmed in 77 of 424 lung transplant recipients (estimated incidence of 0.025 per patient per year; 95% confidence interval 0.018-0.036). At 3 months, 22 recipients (28.8%) developed allograft dysfunction: ten (13%) possible CLAD, six (7.9%) acute rejection and six (7.9%) CLAD. Recipients with the lowest preinfection FEV₁ had a greater risk of developing pneumonia (median (interquartile range) 1.5 (1.1-1.9) vs. 2.2 (1.5-2.4) L/s, p 0.003) and a higher odds of receiving antibiotics (1.6 (1.3-2.3) vs. 2.3 (1.9-2.5) L/s, p 0.017; odds ratio 0.52, 95% confidence interval 0.27-0.99). Compared to tracheobronchitis/bronchiolitis, RSV-induced pneumonia led more frequently to hospitalization (91.7%, 22 vs. 58.0%, 29, p 0.003) and intensive care unit admission (33.3%, 8 vs. 0, p < 10^-3). For ribavirin-treated recipients (24.7%, 19) and azithromycin prophylaxis (50.6%, 39), 3-month FEV₁ values were not different from untreated recipients. The overall mortality was 2.5% at 1 month and 5.3% at 6 months, unrelated to RSV.

CONCLUSIONS

At 3 months after RSV-confirmed infection, 22 recipients (28.8%) had new allograft dysfunction. Ribavirin treatment and azithromycin prophylaxis did not prevent FEV₁ decline.

Identifying host microRNAs in bronchoalveolar lavage samples from lung transplant recipients infected with Aspergillus

BACKGROUND

MicroRNAs (miRNAs) are small non-coding RNAs of ∼22 nucleotides that play a crucial role in post-transcriptional regulation of gene expression. Dysregulation of miRNA expression has been shown during microbial infections. We sought to identify miRNAs that distinguish invasive aspergillosis (IA) from non-IA in lung transplant recipients (LTRs).

METHODS

We used NanoString nCounter Human miRNA, version 3, panel to measure miRNAs in bronchoalveolar lavage (BAL) samples from LTRs with Aspergillus colonization (ASP group) (n = 10), those with Aspergillus colonization and chronic lung allograft dysfunction (CLAD) (ASPCLAD group) (n = 7), those with IA without CLAD (IA group) (n = 10), those who developed IA with CLAD (IACLAD group) (n = 9), and control patients (controls) (n = 9). The miRNA profile was compared using the permutation test of 100,000 trials for each of the comparisons. We used mirDIP to obtain their gene targets and pathDIP to determine the pathway enrichment.

RESULTS

We performed pairwise comparisons between patient groups to identify differentially expressed miRNAs. A total of 5 miRNAs were found to be specific to IA, including 4 (miR-145-5p, miR-424-5p, miR-99b-5p, and miR-4488) that were upregulated and the pair (miR-4454 + miR-7975) that was downregulated in IA group vs controls. The expression change for these miRNAs was specific to patients with IA; they were not significantly differentiated between IACLAD and IA groups. Signaling pathways associated with an immunologic response to IA were found to be significantly enriched.

CONCLUSIONS

We report a set of 5 differentially expressed miRNAs in the BAL of LTRs with IA that might help in the development of diagnostic and prognostic tools for IA in LTRs. However, further investigation is needed in a larger cohort to validate the findings.

Performance of existing definitions and tests for the diagnosis of invasive aspergillosis in critically ill, adult patients: A systematic review with qualitative evidence synthesis

OBJECTIVES

To summarize the available evidence on the diagnostic performance for invasive aspergillosis (IA) in non-hematological, non-solid organ transplantation critically ill patients of the following: (i) existing definitions of IA (developed either for classical immunocompromised populations or for non-immunocompromised critically ill patients); (ii) laboratory tests; (iii) radiology tests.

METHODS

A systematic review was performed by evaluating studies assessing the diagnostic performance for IA of a definition/s and/or laboratory/radiology test/s vs. a reference standard (histology) or a reference definition.

RESULTS

Sufficient data for evaluating the performance of existing definitions and laboratory tests for the diagnosis of IA in critically ill patients is available only for invasive pulmonary aspergillosis. Against histology/autopsy as reference, the AspICU definition showed a promising diagnostic performance but based on small samples and applicable only to patients with positive respiratory cultures. Studies on laboratory tests consistently indicated a better diagnostic performance of bronchoalveolar lavage fluid (BALF) galactomannan (GM) than serum GM, and a suboptimal specificity of BALF and serum (1,3)-β-D-glucan.

CONCLUSIONS

Evidence stemming from this systematic review will guide the discussion for defining invasive aspergillosis within the FUNDICU project. The project aims to develop a standard set of definitions for invasive fungal diseases in critically ill, adult patients.

Granuloma in the explanted lungs: Infectious causes and impact on post-lung transplant mycobacterial infection

INTRODUCTION

The significance of granuloma in explanted lungs of lung transplant recipients (LTR) on the development of post-transplant mycobacterial infection is unclear.

METHODS

A retrospective review comparing LTRs and heart-lung transplant (H-LTR) recipients with granuloma in the explanted lungs between 2000 and 2012 (excluding those LTRs with granuloma due to sarcoidosis) and LTRs or H-LTRs without granuloma. Patients were followed for 2 years post-transplant.

RESULTS

A total of 144 LTRs and 4 H-LTRs with granulomas (75 necrotizing and 73 non-necrotizing) and a comparator cohort of 144 LTRs and 4 H-LTRs without granuloma were analyzed. In LTRs with granulomas, identification of infectious organisms was more common by histopathology (35 AFB and 22 fungal) compared to cultures (six NTM and seven fungal) taken around time of the transplant. LTRs with granulomas were more likely to have pre-transplant non-tuberculous mycobacteria (NTM) infection compared to LTRs without granuloma; P < .01. In the multivariate analysis, having granuloma or positive mycobacterial cultures at time of transplant were associated with increased risk of post-transplant mycobacterial infection (HR = 1.8 95% CI [1.024-3.154]; P = .041 and HR = 2.083 95% CI [1.011-4.292]; P = .047). Although there was a trend toward increase mycobacterial disease in those with granulomas P = .056, there was no difference in survival post-transplantation between those with or without granuloma in the explanted lung; P = .886.

CONCLUSION

The presence of granuloma in the explanted lungs of LTRs or positive mycobacterial cultures at time of transplant is associated with an increased risk of mycobacterial infection post-transplant.

Challenges in the Diagnosis and Management of Bacterial Lung Infections in Solid Organ Recipients: A Narrative Review

Respiratory infections pose a significant threat to the success of solid organ transplantation, and the diagnosis and management of these infections are challenging. The current narrative review addressed some of these challenges, based on evidence from the literature published in the last 20 years. Specifically, we focused our attention on (i) the obstacles to an etiologic diagnosis of respiratory infections among solid organ transplant recipients, (ii) the management of bacterial respiratory infections in an era characterized by increased antimicrobial resistance, and (iii) the development of antimicrobial stewardship programs dedicated to solid organ transplant recipients.

Clinical outcomes of ceftazidime-avibactam in lung transplant recipients with infections caused by extensively drug-resistant gram-negative bacilli

Background

Infections produced by extensively drug-resistant (XDR) gram-negative bacilli (GNB) in solid organ transplant (SOT) are an important cause of morbidity and mortality. Ceftazidime/avibactam (CAZ-AVI) is a novel β-lactam/β-lactamase combination antibiotic with anti-GNB activity, but experience in real clinical practice with CAZ-AVI in lung transplant (LT) recipients is limited.

Methods

We conducted a retrospective study of patients with XDR-GNB infection who received at least 3 days of CAZ-AVI in the Department of Lung Transplantation Between December 2017 and December 2018 at China-Japan friendship hospital (CJFH). The general information, clinical manifestations, laboratory examinations, treatment course, and outcomes were summarized.

Results

A total of 10 patients who underwent LT at our center were included. They were all males with a mean age 51 years. Infections after LT included pneumonia and/or tracheobronchitis [n=9; 90% (9/10)], cholecystitis and blood stream infection (BSI) (n=1, patient 8). In these 10 LT recipients, the incidence of various airway complications was 70% (7/10). Carbapenem-resistant Klebsialla pneumoniae (CRKP) was the predominant pathogen, being detected in 9 patients. Multilocus sequence typing (MLST) analysis showed that all 9 CRKP isolates belonged to ST11. Six patients (6/10, 60%) started CAZ-AVI as salvage therapy after a first-line treatment with other antimicrobials. CAZ-AVI was administered as monotherapy or in combination regimens in 20% (2/10) and 80% (8/10) of patients respectively. There were no difference in temperature before and after CAZ-AVI treatment (P>0.05). White blood cell (WBC) at 7 days, and procalcitonin (PCT) at 7 days and 14 days significantly dropped (P<0.05). After 7-14 days of CAZ-AVI treatment, the PaO₂/FiO₂ratio (P/F ratio) significantly improved (P<0.05). Nine patients (9/10, 90%) obtained negative microbiologic culture of CRKP/CRPA, with a median time to was 6.7 days (range, 1-15 days). However, 5 patients (5/10, 50%) had relapse of CRKP/CRPA infections in the respiratory tract regardless of whether negative microbiologic culture was obtained or not. The 30-day survival rate was 100%, and the 90-day survival rate was 90% (1/10). No severe adverse events related to CAZ-AVI occurred.

Conclusions

CAZ-AVI treatment of CRKP/ CRPA infection in LT recipients was associated with high rates of clinical success, survival, and safety, but recurrent CRKP/CRPA infections in the respiratory tract did occur.

Utility of nested polymerase chain reaction for fungus in detecting clinically suspected patients of invasive fungal infections and its clinical correlation and comparison with fungal culture

Aims and Objectives:

The aim and objective of this study is to detect invasive fungal infections (IFIs) early and with more sensitivity by the nested polymerase chain reaction (PCR) for fungus as compared to fungal culture in clinically suspected patients and also explore its correlation in reference to age, duration of symptoms, immunocompromised status, and other risk factors predisposing to IFIs.

Materials and Methods:

In this cross-sectional study, 50 suspected patients admitted in medical acute care unit/intensive care unit (ACU/ICU) of Sir Sunderlal Hospital, Banaras Hindu University, Varanasi, India, comprised the study. All cases were selected based on the predefined inclusion and exclusion criteria. A detailed history, clinical examination, and all required investigations were done in all suspected patients. Blood samples were taken for nested-PCR for fungus and culture. Nested PCR was performed on extracted DNA form samples collected from all participants under the study.

Results:

Our study comprised of 50 suspected immunocompromised patients of IFIs. Among the participants under the study, the most common risk factor was diabetes mellitus (28% cases). Nearly two-thirds (60%) of the cases were 50 years or more. Around 70% of the cases had a history of illness more than 2 weeks. Nested PCR for fungus came out to be positive in 21/50 patients (42%); however, fungal culture was positive in none. Among the admitted patient in ACU/ICU, 75% were neutropenic.

Conclusions:

IFIs are more common in immunocompromised individuals, patients with comorbidities, long history of symptoms, and elderly population. Nested PCR for fungus has a high sensitivity (as compared to the fungal culture), and also they are rapid in giving the results. Thus, nested PCR for fungus can be used in a cost-effective manner for the early and reliable diagnosis of clinically suspected IFIs.

Donor-derived bacterial infections in lung transplant recipients in the era of multidrug resistance

OBJECTIVES

Our aim was to analyze the prevalence of multidrug-resistant bacterial infections in lung transplant donors and to evaluate its influence on donor-derived bacterial infections.

METHODS

We conducted a retrospective study of adult patients who underwent lung transplantation (2013-2016) at our hospital. Donor-derived bacterial infection was defined as the isolation of the same bacteria with identical antibiotic susceptibility patterns in the recipient and the perioperative cultures from the donor during the first month posttransplantation. We utilized a preventive antibiotic strategy adapted to the bacteria identified in donor cultures using systemic and nebulized antibiotics.

RESULTS

252 lung transplant recipients and 243 donors were included. In 138/243 (56.8%) donors, one bacterial species was isolated from at least one sample; graft colonization (118/243; 48.6%), blood cultures (5/243; 2.1%) and the contamination of preservation fluids (56/243; 23%). Multidrug-resistant bacteria were isolated from 12/243 (4.9%) donors; four Enterobacterales, four Stenotrophomonas maltophilia, three Pseudomonas aeruginosa and one methicillin-resistant Staphylococcus aureus. There was no transmission of these multidrug-resistant bacteria. Donor-derived infections, primarily tracheobronchitis due to non-MDR bacteria, were diagnosed in 7/253 (2.9%) recipients, with good clinical outcomes.

CONCLUSIONS

The lungs of donors colonized with multidrug-resistant bacteria may be safely used when recipients receive prompt tailored antibiotic treatment.

Risk factors and mortality in invasive Rasamsonia spp. infection: Analysis of cases in the FungiScope® registry and from the literature

BACKGROUND

The new Rasamsonia spp. complex can develop invasive infection in immunosuppression or chronic pulmonary disease. It has potential to be misidentified as other genera due to morphological similarities. Nowadays, there is a gap of knowledge on this fungi.

OBJECTIVES

To provide knowledge base of risk factors and therapeutic decisions in invasive Rasamsonia spp. complex infection.

PATIENTS/METHODS

Cases of invasive infection due to Rasamsonia spp. (formerly Geosmithia/Penicillium spp.) from FungiScope^® registry and all reported cases from a literature were included.

RESULTS

We identified 23 invasive infections due to Rasamsonia spp., six (26.1%) in the FungiScope^® registry. Main risk factors were chronic granulomatous disease (n = 12, 52.2%), immunosuppressive treatment (n = 10, 43.5%), haematopoietic stem cell transplantation (n = 7, 30.4%), graft-versus-host disease and major surgery (n = 4, 17.4%, each). Predominantly affected organs were the lungs (n = 21, 91.3%), disease disseminated in seven cases (30.4%). Fungal misidentification occurred in 47.8% (n = 11), and sequencing was used in 69.6% of the patients (n = 16) to diagnose. Breakthrough infection occurred in 13 patients (56.5%). All patients received antifungal treatment, mostly posaconazole (n = 11), caspofungin (n = 10) or voriconazole (n = 9). Combination therapy was administered in 13 patients (56.5%). Susceptibility testing showed high minimum inhibitory concentrations for azoles and amphotericin B, but not for echinocandins. No preferable treatment influencing favourable outcome was identified. Overall mortality was 39% (n = 9).

CONCLUSION

Rasamsonia spp. are emerging fungi causing life-threatening infections, especially in immunocompromised and critically ill patients. Mortality is high. Treatment is challenging and clinicians dealing with this patient population should become aware of this infection constituting a medical emergency.

Absence of evidence that respiratory viral infections influence pediatric lung transplantation outcomes: Results of the CTOTC-03 study

Based on reports in adult lung transplant recipients, we hypothesized that community-acquired respiratory viral infections (CARVs) would be a risk factor for poor outcome after pediatric lung transplant. We followed 61 pediatric lung transplant recipients for 2+ years or until they met a composite primary endpoint including bronchiolitis obliterans syndrome/obliterative bronchiolitis, retransplant, or death. Blood, bronchoalveolar lavage, and nasopharyngeal specimens were obtained with standard of care visits. Nasopharyngeal specimens were obtained from recipients with respiratory viral symptoms. Respiratory specimens were interrogated for respiratory viruses by using multiplex polymerase chain reaction. Donor-specific HLA antibodies, self-antigens, and ELISPOT reactivity were also evaluated. Survival was 84% (1 year) and 68% (3 years). Bronchiolitis obliterans syndrome incidence was 20% (1 year) and 38% (3 years). The primary endpoint was met in 46% of patients. CARV was detected in 156 patient visits (74% enterovirus/rhinovirus). We did not find a relationship between CARV recovery from respiratory specimens and the primary endpoint (hazard ratio 0.64 [95% confidence interval: 0.25-1.59], P = .335) or between CARV and the development of alloimmune or autoimmune humoral or cellular responses. These findings raise the possibility that the immunologic impact of CARV following pediatric lung transplant is different than that observed in adults.

Rabbit antithymocyte globulin for the treatment of chronic lung allograft dysfunction

BACKGROUND

Chronic lung allograft dysfunction (CLAD) is the leading cause of death beyond the first year after lung transplantation. Several treatments have been used to prevent the progression or reverse the effects of CLAD. Cytolytic therapy with rabbit antithymocyte globulin (rATG) has previously shown to be a potential option. However, the effect on patients with restrictive allograft syndrome (RAS) versus bronchiolitis obliterans syndrome (BOS) and the effect of cumulative dosing are unknown.

METHODS

The charts of lung transplant patients treated with rATG at Barnes-Jewish Hospital from 2009 to 2016 were retrospectively reviewed. The primary outcome was response to rATG; patients were deemed responders if their FEV₁ improved in the 6 months after rATG treatment. Safety endpoints included incidence of serum sickness, cytokine release syndrome, malignancy, and infectious complications.

RESULTS

108 patients were included in this study; 43 (40%) patients were responders who experienced an increase in FEV₁ after rATG therapy. No predictors of response to rATG therapy were identified. Serum sickness occurred in 22% of patients, 15% experienced cytokine release syndrome, and 19% developed an infection after therapy.

CONCLUSION

40% of patients with CLAD have an improvement in lung function after treatment with rATG although the improvement was typically minimal.

Defining breakthrough invasive fungal infection-Position paper of the mycoses study group education and research consortium and the European Confederation of Medical Mycology

Breakthrough invasive fungal infections (IFIs) have emerged as a significant problem in patients receiving systemic antifungals; however, consensus criteria for defining breakthrough IFI are missing. This position paper establishes broadly applicable definitions of breakthrough IFI for clinical research. Representatives of the Mycoses Study Group Education and Research Consortium (MSG-ERC) and the European Confederation of Medical Mycology (ECMM) reviewed the relevant English literature for definitions applied and published through 2018. A draft proposal for definitions was developed and circulated to all members of the two organisations for comment and suggestions. The authors addressed comments received and circulated the updated document for approval. Breakthrough IFI was defined as any IFI occurring during exposure to an antifungal drug, including fungi outside the spectrum of activity of an antifungal. The time of breakthrough IFI was defined as the first attributable clinical sign or symptom, mycological finding or radiological feature. The period defining breakthrough IFI depends on pharmacokinetic properties and extends at least until one dosing interval after drug discontinuation. Persistent IFI describes IFI that is unchanged/stable since treatment initiation with ongoing need for antifungal therapy. It is distinct from refractory IFI, defined as progression of disease and therefore similar to non-response to treatment. Relapsed IFI occurs after treatment and is caused by the same pathogen at the same site, although dissemination can occur. These proposed definitions are intended to support the design of future clinical trials and epidemiological research in clinical mycology, with the ultimate goal of increasing the comparability of clinical trial results.

Scopulariopsis/Microascus isolation in lung transplant recipients: A report of three cases and a review of the literature

The current knowledge of invasive Scopulariopsis/Microascus infection in lung transplantation has been derived from only four case reports. Although these fungi are uncommon compared with Aspergillus, they are highly resistant to the current antifungal agents, and the mortality is extremely high. To explore the risk factors, clinical manifestations, notable diagnostic characteristics and outcomes of positive Scopulariopsis/Microascus isolation in lung transplantation patients. We included all cases with positive Scopulariopsis/Microascus isolation from lower respiratory tracts or bronchial mucosa biopsies in our lung transplantation centre. Proven cases from the literature were added. Positive isolation occurred in 2% (3/157) in our centre. Four cases from the literature were added. The mortality could be considered as high as 80%, once the two cases of colonisation were excluded. The average interval between transplantation and positive isolation was 106 (19-131) days. A total of 57.1% of patients had experienced a combination of infection with Aspergillus or other fungi as well as long-term azole antifungal agent treatment before the positive isolation, which may be possible risk factors. The combination of micafungin, posaconazole and terbinafine may be an effective treatment. The peak time of positive isolation was consistent with that of some opportunistic pathogens, and the possible risk factors were the infection of other fungi as well as prior long-term azole antifungal administration. In addition to its high mortality, Scopulariopsis/Microascus was also highly resistant to common antifungal agents and the combination of two or three drugs for therapy was recommended.

Perspectives on Scedosporium species and Lomentospora prolificans in lung transplantation: Results of an international practice survey from ESCMID fungal infection study group and study group for infections in compromised hosts, and European Confederation of Medical Mycology

BACKGROUND

Scedosporium species and Lomentospora prolificans (S/L) are the second most common causes of invasive mold infections following Aspergillus in lung transplant recipients.

METHODS

We assessed the current practices on management of S/L colonization/infection of the lower respiratory tract before and after lung transplantation in a large number of lung transplant centers through an international practice survey from October 2016 to March 2017.

RESULTS

A total of 51 respondents from 45 lung transplant centers (17 countries, 4 continents) answered the survey (response rate 58%). S/L colonization was estimated to be detected in candidates by 48% of centers. Only 18% of the centers used a specific medium to detect S/L colonization. Scedosporium spp. colonization was a contraindication to transplantation in 10% of centers whereas L prolificans was a contraindication in 31%; 22% of centers declared having had 1-5 recipients infected with S/L in the past 5 years.

CONCLUSIONS

This survey gives an overview of the current practices regarding S/L colonization and infection in lung transplant centers worldwide and underscores the need of S/L culture procedure standardization before implementing prospective studies.

Lack of association of Aspergillus colonization with the development of bronchiolitis obliterans syndrome in lung transplant recipients: An international cohort study

BACKGROUND

Bronchiolitis obliterans syndrome (BOS) is a major limitation in the long-term survival of lung transplant recipients (LTRs). However, the risk factors in the development of BOS remain undetermined. We conducted an international cohort study of LTRs to assess whether Aspergillus colonization with large or small conidia is a risk factor for the development of BOS.

METHODS

Consecutive LTRs from January 2005 to December 2008 were evaluated. Rates of BOS and associated risk factors were recorded at 4 years. International Society of Heart and Lung Transplantation criteria were used to define fungal and other infections. A Cox proportional-hazards-model was constructed to assess the association between Aspergillus colonization and the development of BOS controlling for confounders.

RESULTS

A total of 747 LTRs were included. The cumulative incidence of BOS at 4 years after transplant was 33% (250 of 747). Additionally, 22% of LTRs experienced Aspergillus colonization after transplantation. Aspergillus colonization with either large (hazard ratio [HR] = 0.6, 95% confidence interval [CI] = 0.3-1.2, p = 0.12) or small conidia (HR = 0.9, 95% CI = 0.6-1.4, p = 0.74) was not associated with the development of BOS. Factors associated with increased risk of development of BOS were the male gender (HR = 1.4, 95% CI = 1.1-1.8, p = 0.02) and episodes of acute rejection (1-2 episodes, HR = 1.5, 95% CI = 1.1-2.1, p = 0.014; 3-4 episodes, HR = 1.6, 95% CI = 1.0-2.6, p = 0.036; >4 episodes, HR = 2.2, 95% CI = 1.1-4.3, p = 0.02), whereas tacrolimus use was associated with reduced risk of BOS (HR = 0.6, 95% CI = 0.5-0.9, p = 0.007).

CONCLUSIONS

We conclude from this large multicenter cohort of lung transplant patients, that Aspergillus colonization with large or small conidia did not show an association with the development of BOS.

Single-centre study of therapeutic drug monitoring of posaconazole in lung transplant recipients: factors affecting trough plasma concentrations

Objectives

This study describes therapeutic drug monitoring (TDM) of posaconazole suspension and modified release (MR) tablets in lung transplant (LTx) recipients and evaluates factors that may affect posaconazole trough plasma concentration (Cmin).

Methods

A single-centre, retrospective study evaluating posaconazole Cmin in LTx recipients receiving posaconazole suspension or MR tablets between January 2014 and December 2016.

Results

Forty-seven LTx patients received posaconazole suspension, and 78 received the MR tablet formulation; a total of 421 and 617 Cmin measurements were made, respectively. Posaconazole was concurrently administered with proton pump inhibitor in ≥ 90% of patients. The median (IQR) of initial posaconazole Cmin following 300 mg daily of posaconazole tablet was significantly higher than that of 800 mg daily of posaconazole suspension [1.65 (0.97-2.13) mg/L versus 0.81 (0.48-1.15) mg/L, P < 0.01]. Variability in posaconazole Cmin was apparent regardless of the formulations prescribed and dose adjustments were routinely undertaken to maintain therapeutic Cmin. A clear dose-response relationship was observed in patients receiving posaconazole MR tablets. Non-specific adverse events (fatigue, tremor, lethargy, sweating, nausea/vomiting and weight loss) were reported in 3/78 (4%) patients receiving posaconazole MR tablets. Posaconazole Cmin in these three patients was determined to be 9.6, 6.2 and 2.3 mg/L.

Conclusions

The current study has provided clinically important insights into the TDM of posaconazole in LTx recipients. Routine TDM should be undertaken in LTx recipients receiving posaconazole suspension and/or MR tablets.

Epidemiology of invasive fungal infections in lung transplant recipients in Western Australia

BACKGROUND

Invasive fungal infections (IFI) are common after lung transplantation with reported incidence of 8.1% to 16% at 12 months post-transplant, and 3-month all-cause mortality after IFI of 21.7%.

METHODS

We performed a retrospective study of IFI and fungal colonization in lung transplants (LTs) from November 2004 to February 2017.

RESULTS

137 LTs were followed for a median 4.1 years (IQR 2.1-6.2 years). In addition to nebulized amphotericin for the transplant admission to all LTs, systemic mold-active azole was given to 80/130 (61.5%) LTs in the first 6 months post-transplant, 57/121 (47.1%) in the period 6-12 months after transplant, and 93/124 (75%) in the period more than 12 months post-transplant. Mold airways colonization was found in 81 (59.1%) LTs before and 110 (80.3%) LTs after transplantation. There were 13 IFIs for an overall incidence of 2.1 per 100 person-years, occurring at a median 583 days (IQR 182-1110 days) post-transplant, a cumulative incidence of 3.8% at 1 year, 7.6% at 3 years and 10.1% at 5 years post-transplant. All-cause 3-month mortality after IFI was 7.7%. Aspergillus species followed by Scedosporium apiospermum and Cryptococcus species were the commonest fungi causing IFI.

CONCLUSIONS

In our cohort the rate of IFI was comparatively low, likely because of comprehensive early antifungal use and preemptive therapy at any time after transplant. Prospective studies of fungal colonization late after LT are required to determine the risks and benefits of watchful waiting compared to preemptive therapy.

Fungal infection in lung transplant recipients in perioperative period from one lung transplant center

Background

This study aimed to analyze the distribution and prophylaxis strategy of pathogens causing fungal infection in lung transplant recipients from cardiac-brain dead donors in the perioperative period to provide evidence for antifungal prophylaxis and treatment in lung transplant recipients.

Methods

This retrospective study evaluated 194 lung transplant recipients from January 2015 to December 2016. Fungal pathogens were isolated and identified from respiratory tract cultures before and after transplantation in the perioperative period. The galactomannan (GM) testing of bronchoalveolar lavage fluid (BALF) might facilitate the diagnosis of Aspergillus infection. Data were statistically analyzed using SPSS 19.0.

Results

A total of 31 cases of fungal strains isolated from the 194 recipients were identified prior to lung transplantation, and the positive rate was 16.0% (31/194). A total of 27 cases of isolated fungal strains in the 194 recipients were identified, and the positive rate after lung transplantation was 13.9% (27/194) in the perioperative period. A total of 54 cases with positive fungal infection (27.8%) were detected before and after lung transplantation. Overall, 10.3% (20/194) of the lung transplant recipients developed fungal infection in the observation period. The most common fungal pathogens were filamentous fungi and Candida albicans.

Conclusions

Our data suggested that fungi were frequently isolated before and after transplantation from respiratory samples. However, the incidence of invasive fungal infection in lung transplant recipients in the perioperative period was relatively low. Targeted antifungal prophylaxis and treatment should be applied on the basis of the fungal distribution status of different individuals.

Cytokine profile in lung transplant recipients with Aspergillus spp colonization

We studied cytokine profiles in BAL of LTRs with Aspergillus spp colonization who did not progress to IPA in the absence of antifungal prophylaxis. This was a retrospective, single center case-control study. BAL samples were analyzed for cytokines. Patients with Aspergillus spp in BAL who did not receive prophylaxis and did not develop IPA were compared to LTRs with Aspergillus spp that received prophylaxis, LTRs with IPA and controls. Twenty-one patients with Aspergillus colonization who did not develop IPA, seven patients with suspected IPA who received prophylaxis, 4 IPA and 19 controls were included. IPA group had significantly higher levels (median [IQR]) of MIP-1 beta compared to the Suspected IPA group (5 vs 5 P: 0.03). The Suspected IPA group had significantly higher levels of IL-12 (11.38 vs 1 P: 0.0001), IL-1 RA (86.11 vs 23.98 P: 0.0118), IP-10 (22.47 vs 0.86 P: 0.0151), HGF (40.92 vs 16.82 P: 0.0055), and MIG (169.62 vs 5 P: 0.0005) than Colonization group. We have identified a unique cytokine signature in patients with Aspergillus colonization that do not develop IPA. Our study forms basis for a larger study to use these cytokines profile to identify patients at a lower risk of developing IPA.

Infectious complications following heart transplantation in the era of high-priority allocation and extracorporeal membrane oxygenation

Background

Infectious complications are a major cause of morbidity and mortality after heart transplantation (HT). However, the epidemiology and outcomes of these infections in the recent population of adult heart transplant recipients have not been investigated.

Methods

We conducted a single-center retrospective study on infectious complications occurring within 180 days following HT on consecutive heart transplant recipients, from January 2011 to June 2015 at Bichat University Hospital in Paris, France. Risk factors for non-viral infections occurring within 8, 30 and 180 days after HT were investigated using competing risk analysis.

Results

Overall, 113 patients were included. Fifty-eight (51%) HTs were high-priority allocations. Twenty-eight (25%) patients had an extracorporeal membrane oxygenation (ECMO) support at the time of transplantation. Ninety-two (81%) patients developed at least one infection within 180 days after HT. Bacterial and fungal infections (n = 181 episodes) occurred in 80 (71%) patients. The most common bacterial and fungal infections were pneumonia (n = 95/181 episodes, 52%), followed by skin and soft tissue infections (n = 26/181, 14%). Multi-drug-resistant bacteria were responsible for infections in 21 (19%) patients. Viral infections were diagnosed in 44 (34%) patients, mostly Cytomegalovirus infection (n = 39, 34%). In multivariate subdistribution hazard model, prior cardiac surgery (subdistribution hazard ratio sHR = 2.7 [95% CI 1.5–4.6] p < 0.01) and epinephrine or norepinephrine at the time of HT (sHR = 2.3 [95% CI 1.1–5.2] p  = 0.04) were significantly associated with non-viral infections within 8 days after HT. Prior cardiac surgery (sHR = 2.5 [95% CI 1.4–4.4] p < 0.01), recipient age over 60 years (sHR = 2.0 [95% CI 1.2–3.3] p < 0.01) and ECMO following HT (sHR = 1.7 [95% CI 1.0–2.8] p = 0.04) were significantly associated with non-viral infection within 30 days after HT, as well as within 180 days after HT.

Conclusion

This study confirmed the high rate of infections following HT. Recipient age, prior cardiac surgery and ECMO following HT were independent risk factors for early and late bacterial and fungal infections.

Electronic supplementary material

The online version of this article (10.1186/s13613-019-0490-2) contains supplementary material, which is available to authorized users.

Current State of the Diagnosis of Invasive Pulmonary Aspergillosis in Lung Transplantation

As the number of lung transplants performed worldwide each year continues to grow, the success of this procedure is threatened by the incidence of non-CMV infections such as invasive aspergillosis. Despite tremendous efforts and the availability of numerous diagnostic tests (especially in hematological malignancies) the diagnosis of invasive aspergillosis continues to be a challenge. Lung transplantation remains a unique clinical scenario, where additional host defenses are immunocompromized, making many of the available tests unsuitable. In this review we will navigate through the myriad of diagnostic tests currently available and how they apply to this unique patient population, as well as have a look into what the future holds.

Common Infections Following Lung Transplantation

The lungs are the only transplanted organ in direct contact with the ‘outside world’. Infection is a significant cause of morbidity and mortality in lung transplantation. Early accurate diagnosis and optimal management is essential to prevent short and long term complications. Bacteria, including Mycobacteria and Nocardia, viruses and fungi are common pathogens. Organisms may be present in the recipient prior to transplantation, transmitted with the donor lungs or acquired after transplantation. The degree of immunosuppression and the routine use of antimicrobial prophylaxis alters the pattern of post-transplant infections.

Association of pro-inflammatory cytokines and monocyte subtypes in older and younger patients on clinical outcomes after mechanical circulatory support device implantation

Noninvasive immunologic analysis of peripheral blood holds promise for explaining the mechanism of development of adverse clinical outcomes, and may also become a method for patient risk stratification before or after mechanical circulatory support device (MCSD) implantation. Dysregulation of the innate immune system is associated with increased patient age but has yet to be evaluated in the older patient with advanced heart failure undergoing MCSD surgery. Patients pre- and post-MCSD implantation had peripheral blood mononuclear cells (PBMC) and serum isolated. Multiparameter flow cytometry was used to analyze markers of innate cell function, including monocyte subtypes. Multiplex cytokine analysis was performed. MELD-XI and SOFA scores were utilized as surrogate markers of outcomes. Increased levels of pro-inflammatory cytokines including IL-15, TNF-α, and IL-10 were associated with increased MELD-XI and SOFA scores. IL-8, TNF- α, and IL-10 were associated with risk of death after MCSD implantation, even with correction for patient age. Increased frequency of 'classical' monocytes (CD14 + CD16-) were associated with increased MELD-XI and SOFA scores. This suggests that inflammation and innate immune system activation contribute to progression to multiorgan system failure and death after MCSD surgery. Development of noninvasive monitoring of peripheral blood holds promise for biomarker development for candidate selection and patient risk stratification.

Infections in Heart and Lung Transplant Recipients

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

Risk factors for infection after pediatric lung transplantation

Although infection is the leading cause of death in the first year following pediatric lung transplantation, there are limited data on risk factors for early infection. Sepsis remains under-recognized and under-reported in the early post-operative period for lung transplant recipients (LTR). We evaluated the incidence of infection and sepsis, and identified risk factors for infection in the early post-operative period in pediatric LTRs. A retrospective review of medical records of LTRs at a large quaternary-care hospital from January 2009 to March 2016 was conducted. Microbiology results on days 0-7 after transplant were obtained. Sepsis was defined using the 2005 International Pediatric Consensus Conferencecriteria. Risk factors included history of recipient and donor infection, history of multi-drug resistant (MDR) infection, nutritional status, and surgical times. Among the 98 LTRs, there were 22 (22%) with post-operative infection. Prolonged donor ischemic time ≥7 hours, cardiopulmonary bypass(CPB) time ≥340 minutes, history of MDR infection and diagnosis of cystic fibrosis were significantly associated with infection. With multivariable regression analysis, only prolonged donor ischemic time remained significant (OR 4.4, 95% CI: 1.34-14.48). Further research is needed to determine whether processes to reduce donor ischemic time could result in decreased post-transplant morbidity.

Assessment of lung edema during ex-vivo lung perfusion by single transpulmonary thermodilution: A preliminary study in humans

BACKGROUND

Single transpulmonary thermodilution (SD) with extravascular lung water index (EVLWI) could become a new tool to better assess lung graft edema during ex-vivo lung perfusion (EVLP). In this study we compare EVLWI with conventional methods to better select lungs during EVLP and to predict post-transplant primary graft dysfunction (PGD).

METHODS

We measured EVLWI, arterial oxygen/fraction of inspired oxygen (P/F) ratio, and static lung compliance (SLC) during EVLP in an observational study. At the end of EVLP, grafts were accepted or rejected according to a standardized protocol blinded to EVLWI results. We compared the respective ability of EVLWI, P/F, and SLC to predict PGD. Mann-Whitney U-test, Fisher's exact test, and receiver-operating characteristic (ROC) curve data were used for analysis. p < 0.05 was considered statistically significant.

RESULTS

Thirty-five lungs were evaluated by SD during EVLP. Three lungs were rejected for pulmonary edema. Thirty-two patients were transplanted, 8 patients developed Grade 2 or 3 PGD, and 24 patients developed Grade 0 or 1 PGD. In contrast to P/F ratio, SLC, and pulmonary artery pressure, EVLWI differed between these 2 populations (p < 0.001). The area under the ROC for EVLWI assessing Grade 2 or 3 PGD at the end of EVLP was 0.93. Donor lungs with EVLWI >7.5 ml/kg were more likely associated with a higher incidence of Grade 2 or 3 PGD at Day 3.

CONCLUSIONS

Increased EVLWI during EVLP was associated with PGD in recipients.

Suppressed calcineurin-dependent gene expression identifies lung allograft recipients at increased risk of infection

Lung transplant immunosuppression regimens generally include the calcineurin inhibitor tacrolimus. We hypothesized that mean residual expression (MRE) of calcineurin-dependent genes assesses rejection and infection risk better than does tacrolimus trough. We prospectively followed 44 lung allograft recipients at 2 to 18 months posttransplant and measured changes in whole blood interleukin-2, interferon-γ, and granulocyte-macrophage colony-stimulating factor gene expression following a tacrolimus dose. Posttransplant duration, immunosuppressive medication levels, and bronchoscopic rejection and infection assessments were compared with MRE by using generalized-estimating equation-adjusted models. Prednisolone effect on MRE was assessed ex vivo in blood samples from nontransplanted controls. Tacrolimus concentration inhibiting 50% of cytokine production (IC₅₀ ) was measured in a pretransplant subset. Results showed that MRE did not change with diagnosis of rejection but that airway infection was associated with a 20% absolute decrease (95% confidence interval 11%-29%). MRE increased with time after transplant but was not associated with tacrolimus trough. Interestingly, MRE correlated inversely with corticosteroid dose in the study cohort and ex vivo. Pretransplant tacrolimus IC₅₀ depended on the cytokine measured and varied between individuals, suggesting a range in baseline responses to tacrolimus. We conclude that MRE identifies infection risk in lung allograft recipients, potentially integrating calcineurin inhibitor and steroid effects on lymphocyte effector function.

Viral Respiratory Tract Infection During the First Postoperative Year Is a Risk Factor for Chronic Rejection After Lung Transplantation

Supplemental digital content is available in the text.

Background

Chronic lung allograft dysfunction (CLAD) is the major limiting factor for long-term survival in lung transplant recipients. Viral respiratory tract infection (VRTI) has been previously associated with CLAD development. The main purpose of this study was to evaluate the long-term effects of VRTI during the first year after lung transplantation in relation to CLAD development.

Method

Ninety-eight patients undergoing lung transplantation were prospectively enrolled between 2009 and 2012. They were monitored for infections with predefined intervals and on extra visits during the first year, the total follow-up period ranged between 5 and 8 years. Nasopharyngeal swab and bronchoalveolar lavage samples were analyzed using a multiplex polymerase chain reaction panel for respiratory pathogens. Data regarding clinical characteristics and infectious events were recorded.

Results

Viral respiratory tract infection during the first year was identified as a risk factor for long-term CLAD development (P = 0.041, hazard ratio 1.94 [1.03-3.66]) in a time-dependent multivariate Cox regression analysis. We also found that coronavirus in particular was associated with increased risk for CLAD development. Other identified risk factors were acute rejection and cyclosporine treatment.

Conclusions

This study suggests that VRTI during the first year after lung transplantation is associated with long-term CLAD development and that coronavirus infections in particular might be a risk factor.

Clinical risk factors for invasive aspergillosis in lung transplant recipients: Results of an international cohort study

BACKGROUND

Invasive aspergillosis (IA) is a frequent complication in lung transplant recipients (LTRs). Clinical risk factors for IA have not been fully characterized, especially in the era of extensive anti-fungal prophylaxis. The primary objective of this study was to evaluate the clinical risk factors associated with IA in LTRs. The secondary objective was to assess the mortality in LTRs who had at least 1 episode of IA compared with LTRs who never had experienced IA.

METHODS

We conducted an international, multicenter, retrospective cohort study of 900 consecutive adults who received lung transplants between 2005 and 2008 with 4years of follow-up. Risk factors associated with IA were identified using univariate and multiple regression Cox proportional hazards models.

RESULTS

Anti-fungal prophylaxis was administered to 61.7% (555 of 900) of patients, and 79 patients developed 115 episodes of IA. The rate to development of the first episode was 29.6 per 1,000 person-years. Aspergillus fumigatus was the most common species isolated (63% [72 of 115 episodes]). Through multivariate analysis, significant risk factors identified for IA development were single lung transplant (hazard ratio, 1.84; 95% confidence interval, 1.09-3.10; p = 0.02,) and colonization with Aspergillus at 1 year post-transplantation (hazard ratio, 2.11; 95% confidence interval, 1.28-3.49; p = 0.003,). Cystic fibrosis, pre-transplant colonization with Aspergillus spp, and use of anti-fungal prophylaxis were not significantly associated with the development of IA. Time-dependent analysis showed IA was associated with higher mortality rates.

CONCLUSION

Incidence of IA remains high in LTRs. Single-lung transplant and airway colonization with Aspergillus spp. within 1 year post-transplant were significantly associated with IA.