Utilising organs from hepatitis C virus PCR-positive donors in Western Australia.

We transplanted six solid organs from three hepatitis C virus (HCV) polymerase chain reaction (PCR)-positive donors during 2018-2023. Recipients were treated with glecaprevir/pibrentasvir or sofosbuvir/velpatasvir for 4-12 weeks, with all six achieving sustained virological response without significant adverse events. As occurs in other jurisdictions, solid organ transplants from HCR PCR-positive donors can be safely utilised in Australia.

The Western Australian experience of COVID-19 after the borders reopened: evaluation of public health modelling predictions.

BACKGROUND: Western Australia (WA) serves as a unique global case study on the impact of coronavirus disease 2019 (COVID-19) on an isolated, prepared and highly vaccinated population. This study builds upon the study performed by House et al. through an extended data set. AIM: To examine the impact of COVID-19 at the only quaternary hospital in WA following the border opening from 3 March to 17 July 2022. PARTICIPANTS: A total of 257 adults were admitted with COVID-19 under either respiratory or the intensive care unit (ICU). OUTCOMES: Admission numbers, disease severity, ICU admission, prevalence of COVID-19 deterioration risk factors, length of stay and mortality. RESULTS: A total of 257 patients were admitted with COVID-19, under respiratory (81.7%) and ICU (18.3%). COVID-19 was the primary reason for admission for 67.7%. Ten patients died during the study, with seven deaths attributed to COVID pneumonitis. COVID-19 severity was 37.4% mild, 37.0% moderate, 18.3% severe and 7.4% critical. Risk factors for requiring ICU included incomplete immunisation status (P = 0.011), chronic kidney disease (P = 0.008) and Aboriginal and Torres Strait Islander (ATSI) ethnicity. The WA Department of Health predicted that the number of hospitalisations and ICU cases were significantly higher than the actual number of cases. CONCLUSION: The number of hospitalisations and ICU COVID-19 cases were significantly less than predicted, likely due to high population vaccination rates prior to border opening. The main risk factors for COVID-19 severity were incomplete immunisation and ATSI ethnicity.

The unique COVID-19 experience in Western Australia: lessons learnt.

BACKGROUND: Western Australia (WA) was in a unique position to experience coronavirus disease 2019 (COVID-19) in a highly vaccinated and geographically isolated population. AIM: To describe the COVID-19 Omicron experience at the only quaternary hospital in WA following border opening from 3 March to 11 May 2022. PARTICIPANTS: A total of 158 adults with microbiologically confirmed COVID-19 were admitted to the respiratory or intensive care unit (ICU). OUTCOMES: Admission numbers, disease severity, prevalence of COVID-19 deterioration risk factors, immunisation status, severity of infection, immunosuppression and treatment regimen. RESULTS: One hundred fifty-eight COVID-19-positive patients were admitted to the respiratory ward (n = 123) and the ICU (n = 35) during the study period. COVID-19 infection was the primary admission reason in 32.9% of patients, 51.3% were male and the median age was 62 years. Aboriginal or Torres Strait Islanders (ATSI) were overrepresented (13.3%). Care was predominantly ward based (77.2%). Nearly half of the patients had mild COVID-19 (49.4%). Dexamethasone was the most common treatment provided to patients (58.2%). The median length of stay was 5.8 days (interquartile range, 5-15). Eight patients died during the study period (5.1%), with three of those deaths attributable to COVID-19. CONCLUSIONS: COVID-19 case numbers following WA state border opening were of lower care acuity and disease severity than predicted. Two-thirds of admissions were for other primary diagnoses, with incidental COVID detection. Hospital admissions were overrepresented by partially or unvaccinated patients and by ATSI Australians. An increase in social support along with general and geriatric medicine speciality input were required to treat hospitalised COVID-19 cases in the WA Omicron wave.

Mycoplasma and Ureaplasma Donor-Derived Infection and Hyperammonemia Syndrome in 4 Solid Organ Transplant Recipients From a Single Donor.

Hyperammonemia syndrome (HS) is a life-threatening condition occurring in solid organ transplant patients, affecting primarily lung recipients, and is associated with Mycoplasma hominis and/or Ureaplasma spp infection. The organ donor was a young man who died of hypoxic brain injury and had urethral discharge antemortem. The donor and 4 solid organ transplant recipients had infection with M hominis and/or Ureaplasma spp. The lung and heart recipients both developed altered conscious state and HS associated with M hominis and Ureaplasma spp infections. Despite treatment with antibiotics and ammonia scavengers, both the lung and heart recipients died at day +102 and day +254, respectively. After diagnosis in the thoracic recipients, screening samples from the liver recipient and 1 kidney recipient were culture positive for M hominis with or without Ureaplasma spp. Neither the liver nor kidney recipients developed HS. Our case series demonstrates the unique finding of M hominis and Ureaplasma spp dissemination from an immunocompetent donor across 4 different organ recipients. Phylogenetic whole genome sequencing analysis demonstrated that M hominis samples from recipients and donor were closely related, suggesting donor-derived infection. Screening of lung donors and/or recipients for Mycoplasma and Ureaplasma spp is recommended, as well as prompt treatment with antimicrobials to prevent morbidity.

A novel highly bio-available itraconazole formulation (SUBA®-Itraconazole) for anti-fungal prophylaxis in lung transplant recipients.

BACKGROUND: Antifungal prophylaxis remains a mainstay of lung transplantation, given invasive fungal infection is a common and serious complication after lung transplantation. Choice of systemic agent to prevent invasive fungal infection varies between centers and funding of agents remains challenging. Our center has recently changed from posaconazole to a highly bioavailable formulation of itraconazole (SUBA®-itraconazole) at substantially reduced cost, but safety and toxicity require further assessment. A retrospective study of lung transplant patients receiving systemic antifungal prophylaxis from December 2016 through December 2019 following change from posaconazole to itraconazole as standard practice. 150 patients with lung transplants were managed in this time period, with 88 (59%) receiving at least 1 mold-active triazole during the study period. 48 (58%) of these patients received SUBA®-itraconazole; 68 (82%) received posaconazole and 10 (12%) received voriconazole. The average cost per patient during the study period was significantly lower on SUBA®-itraconazole (mean $1548/patient/6 month course) than posaconazole (mean $16 921.35/patient/6 month course). Target trough concentrations for prophylaxis of itraconazole > 0.5 mg/L and posaconazole > 0.7 mg/L were achieved on empiric dosing in 49% and 68% respectively. Overall trough itraconazole (0.50 vs 1.12 mg/L, P < .001) and posaconazole (1.37 vs 2.10 mg/L P < .001) concentrations were significantly lower in patients with cystic fibrosis. Calcineurin inhibitor dose changes on introduction or cessation were similar for SUBA®-itraconazole and posaconazole. Breakthrough invasive fungal infection and toxicity were rare. SUBA®-itraconazole is well-tolerated, associated with rare breakthrough invasive fungal infection, and lower cost. Prospective studies following general introduction are required to determine long-term safety, tolerability, and efficacy.

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 ß6 and ß8, and ß-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.

Donation after circulatory death in lung transplantation-five-year follow-up from ISHLT Registry.

BACKGROUND: This study aimed to examine intermediate-term outcomes of lung transplantation (LTx) recipients from donors after circulatory death (DCD). METHODS: We examined the International Society for Heart and Lung Transplantation (ISHLT) Thoracic Transplant Registry data for patients transplanted between January 2003 and June 2017 at 22 centers in North America, Europe, and Australia participating in the DCD Registry. The distribution of continuous variables was summarized as median and interquartile range (IQR) values. Wilcoxon rank sum test was used to compare distribution of continuous variables and chi-square or Fisher's exact test for categorical variables. Kaplan-Meier survival rates after LTx from January 2003 to June 2016 were compared between DCD-III (Maastricht category III withdrawal of life-sustaining therapy [WLST]) only and donors after brain death (DBD) using the log-rank test. Risk factors for 5-year mortality were investigated using Cox multivariate proportional-hazards model. RESULTS: The study cohort included 11,516 lung transplants, of which 1,090 (9.5%) were DCD lung transplants with complete data. DCD-III comprised 94.1% of the DCD cohort. Among the participating centers, the proportion of DCD-LTx performed each year increased from 0.6% in 2003 to 13.5% in 2016. DCD donor management included extubation in 91%, intravenous heparin in 53% and pre-transplant normothermic ex vivo donor lung perfusion in 15%. The median time interval from WLST to cardiac arrest was 15 minutes (IQR: 11-22 minutes) and to cold flush 32 minutes (IQR: 26-41minutes). Compared with DBD, donor age was higher in DCD-III donors (46 years [IQR: 34-55] vs 40 years [IQR: 24-52]), bilateral LTx was performed more often (88.3% vs 76.6%), and more recipients had chronic obstructive pulmonary disease and emphysema as their transplant indication. Five-year survival rates were comparable (63% vs 61%, p = 0.72). In multivariable analysis, recipient and donor ages, indication diagnosis, procedure type (single vs bilateral and double LTx), and transplant era (2003-2009 vs 2010-2016) were independently associated with survival (p < 0.001), but donor type was not (DCD-III vs DBD; hazard ratio, 1.04 [0.90-1.19], p = 0.61). CONCLUSION: This ISHLT DCD Registry report with 5-year follow-up demonstrated similar favorable long-term survival in DCD-III and DBD lung donor recipients at 22 experienced centers globally. These data indicate that more extensive use of DCD-LTx would increase donor organ availability and may reduce waiting list mortality.

Azithromycin reduces airway inflammation induced by human rhinovirus in lung allograft recipients.

BACKGROUND AND OBJECTIVE: Human rhinovirus (RV) is a common upper and lower respiratory pathogen in lung allograft recipients causing respiratory tract exacerbation and contributing towards allograft dysfunction and long-term lung decline. In this study, we tested the hypothesis that RV could infect both the small and large airways, resulting in significant inflammation. METHODS: Matched large and small airway epithelial cells (AEC) were obtained from five lung allograft recipients. Primary cultures were established, and monolayers were infected with RV1b over time with varying viral titre. Cell viability, receptor expression, viral copy number, apoptotic induction and inflammatory cytokine production were also assessed at each region. Finally, the effect of azithromycin on viral replication, induction of apoptosis and inflammation was investigated. RESULTS: RV infection caused significant cytotoxicity in both large AEC (LAEC) and small AEC (SAEC), and induced a similar apoptotic response in both regions. There was a significant increase in receptor expression in the LAEC only post viral infection. Viral replication was elevated in both LAEC and SAEC, but was not significantly different. Prophylactic treatment of azithromycin reduced viral replication and dampened the production of inflammatory cytokines post-infection. CONCLUSION: Our data illustrate that RV infection is capable of infecting upper and lower AEC, driving cell death and inflammation. Prophylactic treatment with azithromycin was found to mitigate some of the detrimental responses. Findings provide further support for the prophylactic prescription of azithromycin to minimize the impact of RV infection.

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.

Cytomegalovirus viremia in lung transplantation during and after prophylaxis.

BACKGROUND: Lung transplantation has a high risk of cytomegalovirus (CMV) viremia and disease. METHODS: Valganciclovir was planned for 6 months in CMV recipient seropositive (R+) lung transplants (LTs) and given long-term in D+R- LTs. CMV viremia was monitored regularly during and after prophylaxis in all patients. RESULTS: Of 137 LTs, 22 were D+R-, 49 D+R+, 43 D-R+, and 23 D-R-, with median follow up 4.1 years (IQR 2.1-6.2 years). CMV viremia at any time occurred in 44.5% of LTs. CMV viral load >103  c/mL was uncommon (9/77 episodes). CMV viremia occurred at median 665 days (IQR 271-1411 days), in 5.1% LTs <6 months, 20.3% LTs 6-12 months, and 35.8% LTs >12 months. CMV disease occurred in 6 (4.4%) LTs at an overall rate of 1.0 episode per 100 person-years: two of these cases were organ-specific disease, four were CMV syndrome. One case of ganciclovir-resistant CMV was diagnosed. D+R+ and D+R- LTs had higher viremia rates than the D-R+ group. No viremia occurred in D-R- LTs. CMV viremia was not associated with age, gender, type of LT, indication for LT, acute rejection, bronchiolitis obliterans syndrome, or mortality. CONCLUSIONS: Prophylaxis for 6 months in D+R+ and D-R+, and past 12 months in D+R- LTs, with long-term monitoring in all patients using a sensitive assay, and reinstitution of valganciclovir for low-level viremia was effective at markedly reducing the incidence of CMV disease. CMV D-R- LTs do not need routine CMV monitoring.

Risk of anastomotic dehiscence in patients with pulmonary fibrosis transplanted while receiving anti-fibrotics: Experience of the Australian Lung Transplant Collaborative.

BACKGROUND: The new anti-fibrotics pirfenidone and nintedanib are now in widespread use for idiopathic pulmonary fibrosis (IPF), but they may have an adverse impact on pathways involved in wound-healing. This study aimed to establish the safety of anti-fibrotic therapy in the peri-transplant period, particularly with regard to healing of the bronchial anastomosis. METHODS: In this work we assessed a retrospective cohort of patients who had undergone lung transplantation with a diagnosis of pulmonary fibrosis between January 2012 and December 2017. Pre-transplant use of pirfenidone and nintedanib was identified. Anastomotic dehiscence of any extent was determined at bronchoscopy. Known risk factors for anastomotic dehiscence were evaluated in both anti-fibrotic and control groups. RESULTS: Two hundred twenty-six patients (160 males; mean age 59.7 ± 7.8 years) underwent transplantation in Australia for pulmonary fibrosis during the study period. Forty (17.7%) were receiving anti-fibrotics at the time of transplantation (29 with pirfenidone and 11 with nintedanib). There were 7 anastomotic dehiscence events, with overall incidence rates of 7.5% and 2.2% in the anti-fibrotic and control groups, respectively (p = 0.08). All episodes of dehiscence in the anti-fibrotic group and 2 of 4 in the comparator group occurred <6 weeks post-transplant. Survival at 30days was 100% and 96% (p = 0.21) and at 1 year was 93% and 88% (p = 0.01) in the anti-fibrotic and comparator groups, respectively. Two patients with dehiscence died. The other 5 anastomotic defects resolved, with 1 requiring stent insertion. CONCLUSIONS: The incidence of bronchial dehiscence after transplantation for IPF is low and is not significantly higher in patients receiving anti-fibrotic therapy at the time of transplantation.

Influence of lung donor agonal and warm ischemic times on early mortality: Analyses from the ISHLT DCD Lung Transplant Registry.

BACKGROUND: In this study we aimed to assess the impact of agonal time and warm ischemic time on early survival in Category III donation-after-circulatory-death (DCD) donor lung transplants (LTxs) using data reported to the International Society for Heart and Lung Transplantation (ISHLT) DCD Lung Transplant Registry. METHODS: In this retrospective study, data were analyzed for 507 DCD LTxs done between January 2005 and June 2015. DCD lung donor agonal time (defined as withdrawal of life support to cessation of cardiac output) and warm ischemic time (WIT; defined as donor systolic blood pressure <50 mm Hg to cold pulmonary artery flush) were divided into 3 clinical timing categories (<30 minutes, 30 to 60 minutes, >60 minutes) and 3 tertiles. Univariate analysis was undertaken for all categorizations, and Day 30/Day 365 Kaplan‒Meier survival rates were calculated and compared. Multivariable analysis included Cox proportional hazards regression models to estimate hazard of 365-day mortality. RESULTS: Four hundred sixty-five and 301 DCD LTxs had data to analyze in the agonal and warm ischemic time groups, respectively. Day 30 and Day 365 post-transplant survival overall were 96% and 90%, respectively, and not statistically different according to agonal or WIT category or tertile. CONCLUSIONS: Current experience with DCD Category III LTx does not show a relationship between the duration of donor agonal phase or warm ischemic time up to 60 minutes and early survival. These results suggest the true limits of clinical DCD allograft warm ischemic times may not yet be reached. Global variations in clinical DCD practice are apparent. Continued accurate recording and analyses of DCD processes is warranted.

Lung transplant: the Western Australian experience.

BACKGROUND: The Western Australian lung transplant programme commenced in 2004 to serve the growing demand of patients with end-stage lung disease. AIM: This report summarises our 11-year experience in lung transplantation. METHODS: Data on 115 consecutive patients and their respective donors transplanted between 2004 and 2015 were collected. The Kaplan-Meier method was used to estimate survival. Cox regression was used to analyse the impact of donor and recipient characteristics on survival. RESULTS: A total of 88 bilateral, 22 single-lung and 5 heart-lung transplants were performed in Western Australia during the first 11 years of the lung transplant programme. The most common indications for transplantation were interstitial lung disease (30.4%), cystic fibrosis (27.8%) and chronic obstructive pulmonary disease (excluding alpha-1 antitrypsin deficiency) (22.6%). Median recipient age was 50 years. Overall survival rates were 96% at 3 months, 93% at 1 year, 84% at 3 years and 70% at 5 years. Older age and higher BMI negatively impacted survival. Chronic lung allograft dysfunction was the leading cause of late mortality. CONCLUSION: Lung transplantation is a treatment option in end-stage lung disease, with annual transplant rates in Western Australia continuing to rise. Our patients enjoy survival rates that compare favourably against international standards.

Beta-blocker under-use in COPD patients.

BACKGROUND: Cardiovascular (CVS) comorbidities are common in COPD and contribute significantly to morbidity and mortality, especially following acute exacerbations of COPD (AECOPD). Beta-blockers (BBs) are safe and effective in COPD patients, with demonstrated survival benefit following myocardial infarction. We sought to determine if BBs are under-prescribed in patients hospitalized with AECOPD. We also sought to determine inpatient rates of CVS and cerebrovascular complications, and their impact on patient outcomes. METHODS: Retrospective hospital data was collected over a 12-month period. The medical records of all patients >40 years of age coded with a diagnosis of AECOPD were analyzed. Prevalent use and incident initiation of BBs were assessed. Comorbidities including indications and contraindications for BB use were analyzed. RESULTS: Of the 366 eligible patients, 156 patients (42.6%) had at least one indication for BB use - of these patients, only 53 (34.0%) were on BB therapy and 61 (39.1%) were not on BB therapy but had no listed contraindication. Prevalent use of BBs at the time of admission in all 366 patients was 19.7%, compared with 45.6%, 39.6% and 45.9% use of anti-platelets, statins and angiotensin-converting enzyme inhibitor/angiotensin II receptor blockers, respectively. CVS and cerebrovascular complications were common in this population (57 patients, 16%) and were associated with longer length of stay (p<0.01) and greater inpatient mortality (p=0.02). CONCLUSIONS: BBs are under-prescribed in COPD patients despite clear indication(s) for their use. Further work is required to explore barriers to BB prescribing in COPD patients.

Mesenchymal Stromal Cell Therapy for Chronic Lung Allograft Dysfunction: Results of a First-in-Man Study.

Chronic lung transplant rejection (termed chronic lung allograft dysfunction [CLAD]) is the main impediment to long-term survival after lung transplantation. Bone marrow-derived mesenchymal stromal cells (MSCs) represent an attractive cell therapy in inflammatory diseases, including organ rejection, given their relative immune privilege and immunosuppressive and tolerogenic properties. Preclinical studies in models of obliterative bronchiolitis and human trials in graft versus host disease and renal transplantation suggest potential efficacy in CLAD. The purpose of this phase 1, single-arm study was to explore the feasibility and safety of intravenous delivery of allogeneic MSCs to patients with advanced CLAD. MSCs from unrelated donors were isolated from bone marrow, expanded and cryopreserved in a GMP-compliant facility. Patients had deteriorating CLAD and were bronchiolitis obliterans (BOS) grade ≥ 2 or grade 1 with risk factors for rapid progression. MSCs (2 x 106 cells per kilogram patient weight) were infused via a peripheral vein twice weekly for 2 weeks, with 52 weeks follow-up. Ten Patients (5 male, 8 bilateral, median [interquartile range] age 40 [30-59] years, 3 BOS2, 7 BOS3) participated. MSC treatment was well tolerated with all patients receiving the full dosing schedule without any procedure-related serious adverse events. The rate of decline in forced expiratory volume in one second slowed after the MSC infusions (120 ml/month preinfusion vs. 30 ml/month postinfusion, p = .08). Two patients died at 152 and 270 days post-MSC treatment, both from progressive CLAD. In conclusion, infusion of allogeneic bone marrow-derived MSCs is feasible and safe even in patients with advanced CLAD. Stem Cells Translational Medicine 2017;6:1152-1157.

Acute irreversible oxalate nephropathy in a lung transplant recipient treated successfully with a renal transplant.

We report a 29 year old male cystic fibrosis patient with end stage lung disease and normal renal function who underwent a sequential double lung transplant. Medical history included: an ileal resection and pancreatic exocrine dysfunction. The postoperative period was complicated with haemorrhage and repeat surgery, requiring multiple blood transfusions and extensive antibiotic cover. Pancreatic supplements were interrupted. Acute renal failure attributed to haemodynamically-mediated acute tubular necrosis was managed expectantly. He remained dialysis dependent 8 weeks post surgery and was maintained on triple immunosuppression with tacrolimus, mycophenolate and prednisolone. A DTPA study was consistent with ATN. Renal biopsy revealed features consistent with tubular injury due to acute oxalate nephropathy (AON). Further biochemical characterization excluded primary hyperoxaluria but confirmed increased 24 hour urinary oxalate. He was maintained on enhanced frequency HDF and subsequently received an uncomplicated live related renal transplant 10 months post lung transplant with only additional basiliximab. Calcium carbonate was continued to manage post transplant hyperoxaluria and an early renal biopsy excluded recurrent oxalate injury. Enteric hyperoxaluria due to malabsorption in patients with CF especially with ileal resection, in addition to loss of gut Oxalobacter formigenes due to prolonged antimicrobials, increases the risk of AON. Increased awareness of this condition and screening prior to lung transplant is recommended.

Regional differences in susceptibiity of bronchial epithelium to mesenchymal transition and inhibition by the macrolide antibiotic azithromycin.

OBJECTIVE: Dysregulated repair following epithelial injury is a key forerunner of disease in many organs, and the acquisition of a mesenchymal phenotype by the injured epithelial cells (epithelial to mesenchymal transition, EMT) may serve as a source of fibrosis. The macrolide antibiotic azithromycin and the DNA synthesis inhibitor mycophenolate are in clinical use but their mechanism of action remains unknown in post-transplant bronchiolitis obliterans syndrome (BOS). Here we determined if regional variation in the EMT response to TGFß1 underlies the bronchiolocentric fibrosis leading to BOS and whether EMT could be inhibited by azithromycin or mycophenolate. METHODS/RESULTS: We found that small and large airway epithelial cells from stable lung transplant patients underwent EMT when stimulated with TGFß1, however mesenchymal protein expression was higher and loss of epithelial protein expression more complete in small airway epithelial cells. This regional difference was not mediated by changes in expression of the TGFßRII or Smad3 activation. Azithromycin potentially inhibited EMT in both small and large airway epithelial cells by inhibiting Smad3 expression, but not activation. CONCLUSION: Collectively, these observations provide a biologic basis for a previously unexplained but widely observed clinical phenomena, and a platform for the development of new approaches to fibrotic diseases.

The airway epithelium is a direct source of matrix degrading enzymes in bronchiolitis obliterans syndrome.

BACKGROUND: Long-term survival after lung transplantation is hindered by the development of bronchiolitis obliterans syndrome (BOS), and recent evidence suggests that dysregulated epithelial repair may underlie its development. Because matrix metalloproteinase (MMP) -2 and MMP-9 secretion is integral to repair, we hypothesized that airway epithelial cells from patients with BOS would over-express these matrix-degrading enzymes. METHODS: Cells obtained from bronchial and bronchiolar brushings from patients with and without BOS (without acute rejection or infection) were analyzed via quantitative polymerase chain reaction and immunocytochemistry for MMP-2, and MMP-9 gene and protein expression. The expression of tissue inhibitor of metalloproteinase (TIMP)2 and TIMP1 was also assessed. MMP activity in bronchoalveolar lavage was determined via gelatin zymography. RESULTS: MMP-2 and MMP-9 production was significantly higher in bronchoalveolar lavage (3.85- and 11.59-fold, p < 0.001) and airway epithelium (MMP-2 bronchial: 6.33-fold, bronchiolar: 3.57-fold, both p < 0.001; MMP-9 bronchial: 32.55-fold, p < 0.001; bronchiolar: 8.60-fold, p = 0.01) in patients with BOS, but expression in patients without BOS was not different from healthy controls. TIMP expression was similar in patients with and without BOS. Immunostaining confirmed that the airway epithelium was a direct source of MMP-2 and MMP-9 expression in patients with BOS. CONCLUSION: In patients with BOS, the airway epithelium over-expresses MMPs, even in the absence of acute rejection or infection. Dysregulated epithelial repair may be a key feature of BOS.

Oil red O stain of alveolar macrophages is an effective screening test for gastroesophageal reflux disease in lung transplant recipients.

BACKGROUND: Gastroesophageal reflux disease (GORD) and microaspiration may be associated with acute graft dysfunction and development of obliterative bronchiolitis (OB) after lung transplantation. The "gold standard" for diagnosis of GORD is the 24-hour esophageal pH-monitoring study, although no simple, non-invasive screening test is routinely employed. Oil red O staining of alveolar macrophages in bronchoalveolar lavage (BAL) fluid identifies exogenous lipid and may be a surrogate marker for microaspiration. In this study we aimed to assess the utility of the lipid index in identifying patients with significant GORD. METHODS: Our investigation was a prospective analysis of 34 lung transplant patients who were transplanted between April 1999 and July 2006 at a single institution. All patients with recurrent respiratory infections, recurrent acute rejection, unexplained graft dysfunction or newly diagnosed OB had Oil red O staining of alveolar macrophages on BAL specimens at bronchoscopy and 24-hour esophageal pH monitoring. A quantitative assessment called the lipid index was performed resulting in a score from 0 to 400. Abnormal 24-hour pH studies were defined as acid exposure >3.4% in the distal and/or >1% in the proximal esophageal site. RESULTS: Thirty-four patients with a mean age 36.1 years and mean post-operative day of 571 +/- 648 had lipid indices of 143 +/- 94 (range 3 to 341). Twenty-four-hour pH studies revealed a distal mean of 16.1 +/- 6.2% and proximal mean of 6.4 +/- 3.7%. A lipid index >150 was 82.3% sensitive and 76.4% specific for an abnormal 24-hour pH result. Foreign material present on cytology of bronchial fluid seen in 28% of patients showed poor correlation with Oil red O stains and pH studies. CONCLUSIONS: The lipid index is an effective, non-invasive screening test that provides direct evidence of esophageal aspiration. Patients with high positive results should proceed to surgical assessment for Nissen fundoplication.