The Effectiveness of Culture-Directed Preemptive Anti-Aspergillus Treatment in Lung Transplant Recipients at One Year After Transplant

Risk Factors for Early Fungal Disease in Solid Organ Transplant Recipients: A Systematic Review and Meta-analysis

BACKGROUND

Invasive fungal infections are associated with high morbidity in solid organ transplant recipients. Risk factor modification may help with preventative efforts. The objective of this study was to identify risk factors for the development of fungal infections within the first year following solid organ transplant.

METHODS

We searched for eligible articles through February 3, 2023. Studies published after January 1, 2001, that pertained to risk factors for development of invasive fungal infections in solid organ transplant were reviewed for inclusion. Of 3087 articles screened, 58 were included. Meta-analysis was conducted using a random-effects model to evaluate individual risk factors for the primary outcome of any invasive fungal infections and invasive candidiasis or invasive aspergillosis (when possible) within 1 y posttransplant.

RESULTS

We found 3 variables with a high certainty of evidence and strong associations (relative effect estimate ≥ 2) to any early invasive fungal infections across all solid organ transplant groups: reoperation (odds ratio [OR], 2.92; confidence interval [CI], 1.79-4.75), posttransplant renal replacement therapy (OR, 2.91; CI, 1.87-4.51), and cytomegalovirus disease (OR, 2.97; CI, 1.78-4.94). Both posttransplant renal replacement therapy (OR, 3.36; CI, 1.78-6.34) and posttransplant cytomegalovirus disease (OR, 2.81; CI, 1.47-5.36) increased the odds of early posttransplant invasive aspergillosis. No individual variables could be pooled across groups for invasive candidiasis.

CONCLUSIONS

Several common risk factors exist for the development of any invasive fungal infections in solid organ transplant recipients. Additional risk factors for invasive candidiasis and aspergillosis may be unique to the pathogen, transplanted organ, or both.

Risk Factors for Invasive Fungal Infection in Lung Transplant Recipients on Universal Antifungal Prophylaxis

Background

Many centers use universal antifungal prophylaxis after lung transplant, but risk factors for invasive fungal infection (IFI) in this setting are poorly described.

Methods

This retrospective, single-center cohort study including 603 lung transplant recipients assessed risk factors for early (within 90 days of transplant) invasive candidiasis (IC) and invasive mold infection (IMI) and late (90-365 days after transplant) IMI using Cox proportional hazard regression.

Results

In this cohort, 159 (26.4%) patients had 182 IFIs. Growth of yeast on donor culture (hazard ratio [HR], 3.30; 95% CI, 1.89-5.75) and prolonged length of stay (HR, 1.02; 95% CI, 1.01-1.03) were associated with early IC risk, whereas transplantation in 2016 or 2017 (HR, 0.21; 95% CI, 0.06-0.70; HR, 0.25; 95% CI, 0.08-0.80, respectively) and female recipient sex (HR, 0.53; 95% CI, 0.30-0.93) were associated with reduced risk. Antimold therapy (HR, 0.21; 95% CI, 0.06-0.78) was associated with lower early IMI risk, and female donor sex (HR, 0.40; 95% CI, 0.22-0.72) was associated with lower late IMI risk. Recent rejection was a risk factor for late IMI (HR, 1.73; 95% CI, 1.02-2.95), and renal replacement therapy predisposed to early IC, early IMI, and late IMI (HR, 5.67; 95% CI, 3.01-10.67; HR, 7.54; 95% CI, 1.93-29.45; HR, 5.33; 95% CI, 1.46-19.49, respectively).

Conclusions

In lung transplant recipients receiving universal antifungal prophylaxis, risk factors for early IC, early IMI, and late IMI differ.

Associations between invasive aspergillosis and cytomegalovirus in lung transplant recipients: a nationwide cohort study

Cytomegalovirus (CMV) and invasive aspergillosis (IA) cause morbidity among lung transplant recipients (LTXr). Early diagnosis and treatment could improve outcomes. We examined rates of CMV after IA and vice versa to assess whether screening for one infection is warranted after detecting the other. All Danish LTXr, 2010-2019, were followed for IA and CMV for 2 years after transplantation. IA was defined using ISHLT criteria. Adjusted incidence rate ratios (aIRR) were estimated by Poisson regression adjusted for time after transplantation. We included 295 LTXr, among whom CMV and IA were diagnosed in 128 (43%) and 48 (16%). The risk of CMV was high the first 3 months after IA, IR 98/100 person-years of follow-up (95% CI 47-206). The risk of IA was significantly increased in the first 3 months after CMV, aIRR 2.91 (95% CI 1.32-6.44). Numbers needed to screen to diagnose one case of CMV after IA, and one case of IA after CMV was approximately seven and eight, respectively. Systematic screening for CMV following diagnosis of IA, and vice versa, may improve timeliness of diagnosis and outcomes for LTXr.

Antifungal prophylaxis and pre-emptive therapy: When and how?

The growing pool of critically ill or immunocompromised patients leads to a constant increase of life-threatening invasive infections by fungi such as Aspergillus spp., Candida spp. and Pneumocystis jirovecii. In response to this, prophylactic and pre-emptive antifungal treatment strategies have been developed and implemented for high-risk patient populations. The benefit by risk reduction needs to be carefully weighed against potential harm caused by prolonged exposure against antifungal agents. This includes adverse effects and development of resistance as well as costs for the healthcare system. In this review, we summarise evidence and discuss advantages and downsides of antifungal prophylaxis and pre-emptive treatment in the setting of malignancies such as acute leukaemia, haematopoietic stem cell transplantation, CAR-T cell therapy, and solid organ transplant. We also address preventive strategies in patients after abdominal surgery and with viral pneumonia as well as individuals with inherited immunodeficiencies. Notable progress has been made in haematology research, where strong recommendations regarding antifungal prophylaxis and pre-emptive treatment are backed by data from randomized controlled trials, whereas other critical areas still lack high-quality evidence. In these areas, paucity of definitive data translates into centre-specific strategies that are based on interpretation of available data, local expertise, and epidemiology. The development of novel immunomodulating anticancer drugs, high-end intensive care treatment and the development of new antifungals with new modes of action, adverse effects and routes of administration will have implications on future prophylactic and pre-emptive approaches.

Fungal infection and colonization in lung transplant recipients with chronic lung allograft dysfunction

BACKGROUND

The incidence and impact of de novo fungal airway colonization and infection in lung transplant recipients (LTRs) with known chronic lung allograft dysfunction (CLAD) has not been established. We aimed to determine the 1-year cumulative incidence and risk factors of de novo fungal colonization or infection in LTRs with CLAD and assess the impact of colonization or infection on post-CLAD survival.

METHODS

Prospectively collected Toronto Lung Transplant Program database and chart review were used for double-LTRs who were diagnosed with CLAD from January 1, 2016 to January 1, 2020 and who were free of airway fungi within 1 year prior to CLAD onset. International Society for Heart and Lung Transplantation definitions were used to define clinical syndromes. Cox-Proportional Hazards Models were used for risk-factor analysis. Survival analysis could not be completed secondary to low number of fungal events; therefore, descriptive statistics were employed for survival outcomes.

RESULTS

We found 186 LTRs diagnosed with CLAD meeting our inclusion criteria. The 1-year cumulative incidence for any fungal event was 11.8% (7.0% for infection and 4.8% for colonization). Aspergillus fumigatus was a causative pathogen in eight of 13 (61.5%) patients with infection and six of nine (66.7%) patients with colonization. No patients with fungal colonization post-CLAD developed fungal infection. Peri-CLAD diagnosis (3 months prior or 1 month after) methylprednisolone bolus (hazards ratio: 8.84, p = .001) increased the risk of fungal events. Most patients diagnosed with fungal infections (53.8%) died within 1-year of CLAD onset.

CONCLUSION

De novo IFIs and fungal colonization following CLAD onset were not common. Fungal colonization did not lead to fungal infection. Methylprednisolone bolus was a significant risk factors for post-CLAD fungal events.

Risk factors of invasive fungal infections in lung transplant recipients: A systematic review and meta-analysis

BACKGROUND

Invasive fungal infection (IFI) remains a common complication after lung transplantation, causing significant morbidity and mortality. We have attempted to quantify systematically risk factors of IFI in lung transplant recipients.

METHODS

Studies were retrieved from Ovid MEDLINE, Ovid Embase, Cochrane database of systematic reviews and Cochrane central register of controlled trials. All case-control and cohort studies evaluating the risk factors of IFI in adult lung transplant recipients were screened. Two researchers reviewed and assessed all studies independently. We pooled the estimated effect of each factor associated with IFI by using a random effect model.

RESULTS

Eight studies were included in the systematic review and 5 studies were eligible for the meta-analysis. Rates of IFI range from 8% to 33% in lung transplant recipients. Independent risk factors for invasive aspergillosis (IA) in lung transplantation include previous fungal colonization (odds ratio [OR] 2.44; 95% confidence interval [CI] 0.08-0.47), cytomegalovirus infection (OR 1.96; 95% CI 1.08-3.56), and single lung transplantation (OR 1.77; 95% CI 1.08-2.91). Pre-emptive antifungal therapy is a protective factor for IA in lung transplant (OR 0.2; 95% CI 0.08-0.47).

CONCLUSION

Cytomegalovirus infection, previous fungal colonization and single lung transplantation independently increase the risk of IA in lung transplant recipients. Pre-emptive antifungal therapy is a protective factor for IA in the lung transplant population.

Managing Fungal Infections in Cystic Fibrosis Patients: Challenges in Clinical Practice

Cystic Fibrosis (CF) is an autosomal recessive disease characterized by a mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) protein. Impairment of the CFTR protein in the respiratory tract results in the formation of thick mucus, development of inflammation, destruction of bronchial tissue, and development of bacterial or fungal infections over time. CF patients are commonly colonized and/or infected with fungal organisms, Candida albicans or Aspergillus fumigatus, with prevalence rates ranging from 5% to 78% in the literature. Risk factors for acquiring fungal organisms include older age, coinfection with Pseudomonas aeruginosa, prolonged use of oral and inhaled antibiotics, and lower forced expiratory volume (FEV₁). There are limited data available to differentiate between contamination, colonization, and active infection. Furthermore, the pathogenicity of colonization is variable in the literature as some studies report a decline in lung function associated with fungal colonization whereas others showed no difference. Limited data are available for the eradication of fungal colonization and the treatment of active invasive aspergillosis in adult CF patients. In this review article, we discuss the challenges in clinical practice and current literature available for laboratory findings, clinical diagnosis, and treatment options for fungal infections in adult CF patients.

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.

Incidence and outcomes of invasive fungal infection among solid organ transplant recipients: A population-based cohort study

BACKGROUND

Invasive fungal infection (IFI) in solid organ transplant (SOT) recipients is associated with significant morbidity and mortality. The long-term probability of post-transplant IFI is poorly understood.

METHODS

We conducted a population-based cohort study using linked administrative healthcare databases from Ontario, Canada, to determine the incidence rate; 1-, 5-, and 10-year cumulative probabilities of IFI; and post-IFI all-cause mortality in SOT recipients from 2002 to 2016. We also determined post-IFI, death-censored renal allograft failure.

RESULTS

We included 9326 SOT recipients (median follow-up: 5.35 years). Overall, the incidence of IFI was 8.3 per 1000 person-years. The 1-year cumulative probability of IFI was 7.4% for lung, 5.4% for heart, 1.8% for liver, 1.2% for kidney-pancreas, and 1.1% for kidney-only allograft recipients. Lung transplant recipients had the highest incidence rate and 10-year probability of IFI: 43.0 per 1000 person-years and 26.4%, respectively. The 1-year all-cause mortality rate after IFI was 34.3%. IFI significantly increased the risk of mortality in SOT recipients over the entire follow-up period (hazard ratio: 6.50, 95% CI: 5.69-7.42). The 1-year probability of death-censored renal allograft failure after IFI was 9.8%.

CONCLUSION

Long-term cumulative probability of IFI varies widely among SOT recipients. Lung transplantation was associated with the highest incidence of IFI with considerable 1-year all-cause mortality.

Mucormycosis in lung transplant recipients: A systematic review of the literature and a case series

BACKGROUND

Mucormycosis is a rare infection in lung transplant recipients (LTR). Our objective was to better define the clinical presentation and optimal management of this frequently lethal infection.

METHODS

A systematic review of the literature was performed to identify all published cases of mucormycosis in LTR using PubMed/MEDLINE. These cases were analyzed together with a new case series from our clinic.

RESULTS

Literature search yielded 44 articles matching the inclusion criteria, describing 121 cases. Six additional cases were identified from our clinic. Data regarding infection site and outcome were available for a total of 53 patients. The lungs were the most common site of infection (62%), followed by rhinocerebral and disseminated disease. Most cases (78%) developed in the first post-transplant year, with over 40% of them in the first month. Additional risk factors for mucormycosis were identified in over half of the patients. Surgical debridement was uncommon in pulmonary infection (9%). Posaconazole therapy was used in 35% of cases, mostly in combination with amphotericin B. Overall mortality was 32% but varied according to site of infection.

CONCLUSION

Mucormycosis in LTRs tends to be an early post-surgical infection, associated with additional risk factors and intensified immunosuppressive states, and most often affects the lungs, where surgical debridement is rarely feasible. Posaconazole as first-line therapy should be further explored.

Early diagnosis of fungal infections in lung transplant recipients, colonization versus invasive disease?

PURPOSE OF REVIEW

The diagnosis of invasive aspergillosis remains challenging in solid organ transplants in general, and in lung transplant recipients, in particular, because of colonization. Lung transplant recipients may be over treated with antifungal drugs because of the lack of appropriate diagnostic tools.

RECENT FINDINGS

A review of the new developments of diagnostic tools and whether this help distinguishing colonization from invasive disease is presented.

SUMMARY

Efforts are being made to develop new tools that will allow us to identify which patients will develop IPA, and those who will be able to control the disease.

Invasive Aspergillosis in solid-organ transplant recipients: Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These updated AST-IDCOP guidelines provide information on epidemiology, diagnosis, and management of Aspergillus after organ transplantation. Aspergillus is the most common invasive mold infection in solid-organ transplant (SOT) recipients, and it is the most common invasive fungal infection among lung transplant recipients. Time from transplant to diagnosis of invasive aspergillosis (IA) is variable, but most cases present within the first year post-transplant, with shortest time to onset among liver and heart transplant recipients. The overall 12-week mortality of IA in SOT exceeds 20%; prognosis is worse among those with central nervous system involvement or disseminated disease. Bronchoalveolar lavage galactomannan is preferred for the diagnosis of IA in lung and non-lung transplant recipients, in combination with other diagnostic modalities (eg, chest CT scan, culture). Voriconazole remains the drug of choice to treat IA, with isavuconazole and lipid formulations of amphotericin B regarded as alternative agents. The role of combination antifungals for primary therapy of IA remains controversial. Either universal prophylaxis or preemptive therapy is recommended in lung transplant recipients, whereas targeted prophylaxis is favored in liver and heart transplant recipients. In these guidelines, we also discuss newer antifungals and diagnostic tests, antifungal susceptibility testing, and special patient populations.

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.

Use of echinocandin prophylaxis in solid organ transplantation

Invasive fungal infections (IFIs) are a major threat to patients undergoing solid organ transplantation (SOT). Owing to improvements in surgical techniques, immunosuppression therapy and antifungal prophylaxis, the incidence of IFIs has been decreasing in recent years. However, IFI-associated morbidity and mortality remain significant. Invasive candidiasis (IC) and aspergillosis (IA) are the main IFIs after SOT. Risk factors for IC and IA continue to evolve, and thus strategies for their prevention should be constantly updated and targeted to both individual patient risk factors and local epidemiology. In this review, we discuss the current epidemiology and risk factors for IFIs in SOT recipients in the context of actual approaches to antifungal prophylaxis, including experience with the use of echinocandins, after SOT.

The myriad challenges of respiratory fungal infection in cystic fibrosis

Fungal infection in cystic fibrosis (CF) is a recognized challenge, with many areas requiring further investigation. Consensus definitions exist for allergic bronchopulmonary aspergillus in CF, but the full scope of clinically relevant non-allergic fungal disease in CF-asymptomatic colonization, transient or chronic infection localized to endobronchial mucus plugs or airway tissue, and invasive disease-is yet to be clearly defined. Recent advances in mycological culture and non-culture identification have expanded the list of both potential pathogens and community commensals in the lower respiratory tract. Here we aim to outline the current understanding of fungal presence in the CF respiratory tract, risk factors for acquiring fungi, host-pathogen interactions that influence the role of fungi from bystander to pathogen, advances in the diagnostic approaches to isolating and identifying fungi in CF respiratory samples, challenges of classifying clinical phenotypes of CF patients with fungi, and current treatment approaches. Development and validation of biomarkers characteristic of different fungal clinical phenotypes, and controlled trials of antifungal agents in well-characterized target populations, remain central challenges to surmount and goals to be achieved.

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.

Risk and outcomes of pulmonary fungal infection after pediatric lung transplantation

BACKGROUND

Prospective studies to determine associated risk factors and related outcomes for pulmonary fungal infection (PFI) after pediatric lung transplant (PLT) are lacking.

METHODS

NIH-sponsored Clinical Trials in Organ Transplantation in Children enrolled PLT candidates, collecting data prospectively for 2 years post-transplant. Demographics, signs/symptoms, radiology, pathology and microbiology were collected. Analyses evaluated for PFI-related risks and outcomes.

RESULTS

In 59 PLT, pre-transplant fungal colonization occurred in 6 donors and 15 recipients. Cystic fibrosis (CF) was associated with pre-transplant colonization (P < .01). Twenty-five (42%) PLT had 26 post-transplant colonizations (median = 67 days, range = 0-750 days) with Candida (13), Aspergillus (4), mold (6) or yeast (3). Post-PLT colonization was not associated with CF, age, or pre-PLT colonization. Thirteen PFIs occurred in 10 (17%) patients, 3 proven (Candida species) and 10 probable (Candida [3], Aspergillus [3], Penicillium [3], and mold [1]). Pulmonary fungal infection was preceded by post-PLT colonization with the same organism in 4 of 13 PFI, but post-PLT colonization did not predict subsequent PFI (P = .87). Older age at transplant was a risk for PFI (P < .01). No mortality was attributed to PFI. Prophylaxis use was not associated with decreased post-PLT colonization (P = .60) or PFI (P = .48).

CONCLUSION

In PLT, PFI and fungal colonization are common but without associated mortality. Post-PLT colonization did not predict PFI. Optimal prevention strategies require additional study.

Fungal Infections After Lung Transplantation

Infection remains a significant source of morbidity and mortality after lung transplant, including fungal infection. Various antifungal prophylactic agents are administered for a variable duration after transplant with the goal of preventing invasive fungal infections. Alternatively, some programs target the use of antifungal agents only in those colonized with Aspergillus spp. Despite prophylaxis or preemptive therapy, a significant number of invasive fungal infections occur after lung transplant. Risk factors for fungal infections include single lung transplant, pretransplant Aspergillus colonization, environmental risks, structural lung disease such as cystic fibrosis, augmented immunosuppression, sinus disease, and use of indwelling airway stents.

Pentraxin 3 levels in bronchoalveolar lavage fluid of lung transplant recipients with invasive aspergillosis

BACKGROUND

Invasive aspergillosis is the most common invasive fungal infection in lung transplant recipients. The use of galactomannan testing in bronchoalveolar lavage (BAL) fluid has improved diagnosis of invasive aspergillosis; however, false-positive results can lead to overdiagnosis and unnecessary treatment. The use of proinflammatory markers such as pentraxin 3 (PTX3) may help differentiate between Aspergillus colonization and disease.

METHODS

BAL PTX3 concentrations were measured by enzyme-linked immunosorbent assay in 151 lung transplant recipients and 9 healthy control subjects. Patients were characterized as having Aspergillus colonization or invasive disease according to International Society of Heart and Lung Transplantation criteria. Concomitant PTX3values were compared using Mann-Whitney U and Kruskal-Wallis tests.

RESULTS

We analyzed 322 BAL stored samples and identified 15 invasive aspergillosis events, 38 Aspergillus colonizations, and 17 positive galactomannan with negative Aspergillus cultures. Median BAL PTX3 level was significantly higher in patients with invasive aspergillosis compared with patients with Aspergillus colonization and healthy control subjects (439.20 pg/ml [interquartile range (IQR) 168.18-778.90], 68.93 pg/ml [IQR 13.67-156.74], and 13.67 pg/ml [IQR 13.67-121.18]; p < 0.001). Patients with BAL PTX3 value >319 pg/ml with positive galactomannan and patients with BAL PTX3 value >312 pg/ml with positive Aspergillus culture were 4.5 and 5.5 times more likely to have invasive pulmonary aspergillosis, respectively.

CONCLUSIONS

Our study shows that PTX3 measurements in BAL samples were significantly higher among patients with invasive aspergillosis and may help to identify patients with Aspergillus colonization and false-positive galactomannan in BAL samples.

Practice Guidelines for the Diagnosis and Management of Aspergillosis: 2016 Update by the Infectious Diseases Society of America

It is important to realize that guidelines cannot always account for individual variation among patients. They are not intended to supplant physician judgment with respect to particular patients or special clinical situations. IDSA considers adherence to these guidelines to be voluntary, with the ultimate determination regarding their application to be made by the physician in the light of each patient's individual circumstances.

Infectious Triggers of Chronic Lung Allograft Dysfunction

Survival after lung transplantation is limited in large part due to the high incidence of chronic rejection, known as chronic lung allograft dysfunction (CLAD). Pulmonary infections are a frequent complication in lung transplant recipients, due both to immunosuppressive medications and constant exposure of the lung allograft to the external environment via the airways. Infection is a recognized risk factor for the development of CLAD, and both acute infection and chronic lung allograft colonization with microorganisms increase the risk for CLAD. Acute infection by community acquired respiratory viruses, and the bacteria Pseudomonas aeruginosa and Staphylococcus aureus are increasingly recognized as important risk factors for CLAD. Colonization by the fungus Aspergillus may also augment the risk of CLAD. Fostering this transition from healthy lung to CLAD in each of these infectious episodes is the persistence of an inflammatory lung allograft environment.