Airway oscillometry parameters in baseline lung allograft dysfunction: Associations from a multicenter study.

BACKGROUND: Baseline lung allograft dysfunction (BLAD), the failure to achieve ≥80%-predicted spirometry after lung transplant (LTx), is associated with impaired survival. Physiologic abnormalities in BLAD are poorly understood. Airway oscillometry measures respiratory system mechanics and may provide insight into understanding the mechanisms of BLAD. OBJECTIVES: This study aims to describe and measure the association between airway oscillometry parameters [Reactance (Xrs5, Ax), Resistance (Rrs5, Rrs5-19)] (1) stable LTx recipients, comparing those with normal spirometry and those with BLAD; and (2) in recipients with chronic lung allograft dysfunction (CLAD), comparing those with normal baseline spirometry and those with BLAD. METHODS: A multi-center cross-sectional study was performed including bilateral LTx between January 2020 and June 2021. Participants performed concurrent airway oscillometry and spirometry. Multivariable logistic regression was performed to measure the association between oscillometry parameters and BLAD. RESULTS: A total of 404 LTx recipients performed oscillometry and 253 were included for analysis. Stable allograft function was confirmed in 149 (50.2%) recipients (92 (61.7%) achieving normal spirometry and 57 (38.3%) with BLAD). Among stable LTx recipients, lower Xrs5 Z-Score (aOR 0.50 95% CI 0.37-0.76, p = 0.001) was independently associated with BLAD. CLAD was present in 104 (35.0%) recipients. Among recipients with CLAD, lower Xrs5 Z-Score (aOR 0.73 95% CI 0.56-0.95, p = 0.02) was associated with BLAD. CONCLUSIONS: Oscillometry provides novel physiologic insights into mechanisms of BLAD. The independent association between Xrs5 and BLAD, in both stable recipients and those with CLAD suggests that respiratory mechanics, in particular abnormal elastance, is an important physiologic feature. Further longitudinal studies are needed to understand the trajectory of oscillometry parameters in relation to allograft outcomes.

Clinical Challenges of Tacrolimus for Maintenance Immunosuppression Post-Lung Transplantation.

Lung transplantation (LTx) is a successful treatment option for end-stage lung disease, and immunosuppressant regimens, utilized to prevent rejection of the transplanted graft, are paramount to maintaining long-term graft survival. Immunosuppression can be classified as induction, maintenance, and antirejection therapy. This article focuses on maintenance immunosuppression that includes a combination of a calcineurin inhibitor (CNI), cell cycle inhibitor, and corticosteroid. CNIs remain the cornerstone of immunosuppression following LTx, and tacrolimus is now the preferred CNI, based on a better adverse effect profile and some limited evidence for enhanced efficacy. Tacrolimus is associated with a number of unique challenges post-LTx, with erratic and highly variable absorption making it difficult to achieve and maintain therapeutic levels. Current methods of therapeutic drug monitoring are extrapolated from models in liver and kidney transplants and are not validated in the LTx population. Alternative methods of delivering tacrolimus can address some of the issues associated with their use and can be utilized in particular clinical scenarios. Long-term toxicities attributed to tacrolimus, such as nephrotoxicity and neurotoxicity, can limit the long-term success of tacrolimus in preventing allograft rejection. This article emphasizes the current clinical challenges faced when managing LTx recipients with tacrolimus, offers strategies to manage these issues, and highlights the areas that need further research.

Invasive Scedosporium sternal osteomyelitis following lung transplant: Cured.

Scedosporium is an important pathogen in cystic fibrosis (CF) and post-transplant but rarely causes invasive infection. Treatment remains challenging, particularly due to inherent resistance to multiple antifungal agents. We present a young man with CF who developed invasive sternal and rib infection 10-months following lung transplant. The infection has been clinically and radiologically cured with extensive surgery and triazole therapy. This case highlights the importance of adjunctive surgery in addition to prolonged triazole treatment to manage invasive Scedosporium infections in immunosuppressed patients.

ABO incompatible renal transplantation following lung transplantation.

We present management strategies utilised for the first case of an urgent live-donor ABO incompatible B blood group renal transplant, in a patient with a prior A blood group lung transplant for cystic fibrosis. Three years on, renal function is excellent and stable, whilst lung function has improved.

HLA Matching at the Eplet Level Protects Against Chronic Lung Allograft Dysfunction.

Donor selection in lung transplantation (LTx) is historically based upon clinical urgency, ABO compatibility, and donor size. HLA matching is not routinely considered; however, the presence or later development of anti-HLA antibodies is associated with poorer outcomes, particularly chronic lung allograft dysfunction (CLAD). Using eplet mismatches, we aimed to determine whether donor/recipient HLA incompatibility was a significant predictor of CLAD. One hundred seventy-five LTx undertaken at the Alfred Hospital between 2008 and 2012 met criteria. Post-LTx monitoring was continued for at least 12 months, or until patient death. HLA typing was performed by sequence-based typing and Luminex sequence-specific oligonucleotide. Using HLAMatchmaker, eplet mismatches between each donor/recipient pairing were analyzed and correlated against incidences of CLAD. HLA-DRB1/3/4/5+DQA/B eplet mismatch was a significant predictor of CLAD (hazard ratio [HR] 3.77, 95% confidence interval [CI]: 1.71-8.29 p < 0.001). When bronchiolitis obliterans syndrome (BOS) and restrictive allograft syndrome (RAS) were analyzed independently, HLA-DRB1/3/4/5 + DQA/B eplet mismatch was shown to significantly predict RAS (HR 8.3, 95% CI: 2.46-27.97 p < 0.001) but not BOS (HR 1.92, 95% CI: 0.64-5.72, p = 0.237). HLA-A/B eplet mismatch was shown not to be a significant predictor when analyzed independently but did provide additional stratification of results. This study illustrates the importance of epitope immunogenicity in defining donor-recipient immune compatibility in LTx.

Mycobacterium abscessus Complex - a Particular Challenge in the Setting of Lung Transplantation.

Mycobacterium abscessus complex is an emerging pathogen in lung transplant candidates and recipients. M. abscessus complex is widespread in the environment and can cause pulmonary, skin and soft tissue, and disseminated infection, particularly in lung transplant recipients. It is innately resistant to many antibiotics making it difficult to treat. Herein we describe the epidemiology, clinical manifestations, diagnosis and treatment of M. abscessus with an emphasis on lung transplant candidates and recipients. We also outline the areas where data are lacking and the areas where further research is urgently needed.

Comparative analysis of how immune sensitization is defined prior to lung transplantation.

BACKGROUND: Immune sensitization prior to lung transplantation may be associated with worse survival. Using solid phase assays to define sensitization, we assessed the relationship between PRA status, donor specific anti-HLA antibodies (DSA) pre-transplant, cytotoxic cross match results and the clinical outcomes following lung transplantation. METHODS: Luminex assays determined the presence of antibodies to class I and class II MHC molecules prior to lung transplantation. At the time of transplant, the PRA status, the presence of DSA and prospective cytotoxic cross match result were analysed in 195 patients undergoing lung transplantation between June 2008 and June 2012. Clinical outcomes analysed included acute cellular and antibody-mediated rejection, chronic lung allograft dysfunction (CLAD) and mortality. RESULTS: At the time of transplant, 45% of patients had a positive PRA and 29% had DSA. On univariate analysis, the presence of pre-transplant class I or II anti-HLA donor-specific antibodies was not associated with the development of chronic lung allograft dysfunction (CLAD) despite significant associations with PRA status and B-cell crossmatch. CONCLUSION: Defining sensitization using solid phase assays provide additional details regarding donor-specific sensitization but did not provide additional prognostic information to that provided by historically available cell-based cross-match assays.

Outcomes of simultaneous heart-kidney and lung-kidney transplantations: the Australian and New Zealand experience.

BACKGROUND: Heart or lung transplantation alone in individuals with significant pre-existing renal impairment results in high mortality and morbidity. Simultaneous heart-kidney (SHK) or simultaneous lung-kidney (SLK) transplantation may be considered in patients with dual organ failure not suitable for single organ transplantation. AIM: We aimed to outline the Australian and New Zealand experience of SHK and SLK transplantations, focussing on patient characteristics and survival. METHODS: We analysed all SHK and SLK transplants performed in four centres across Australia and New Zealand between 1990 and 2014. RESULTS: Over the study period, 35 SHK and 3 SLK transplants were performed across 4 transplant centres. Mean age at transplantation for SHK transplants was 45 years, and for SLK transplant was 27 years. The most common aetiology of renal failure was glomerulonephritis. Most SHK transplant patients (77%) required renal replacement therapy prior to transplantation, with only one of the three patients undergoing SLK transplant, dialysis dependent. One-year survival for the cohort was 79%, which is lower than reported for single organ transplantation. However, 5- and 10-year survivals of 76% and 68%, respectively, were comparable. Isolated renal graft loss was seen in five patients, with only one patient successfully re-transplanted and the rest commencing dialysis. CONCLUSION: The Australian and New Zealand experience of SHK and SLK includes 38 patients with a high 1-year mortality, but excellent 5- and 10-year survivals. Based on this, it seems reasonable to continue to offer combined organ transplantation to select patients with dual organ failure.

Donation After Circulatory Determination of Death Lung Transplantation for Pulmonary Arterial Hypertension: Passing the Toughest Test.

Lung transplantation (LTx) is a therapeutic option for severe pulmonary arterial hypertension (PAH) patients failing optimal medical therapy. The use of donation after circulatory determination of death (DCDD) donor lungs for PAH LTx has rarely been reported, primarily reflecting concerns that DCDD lungs represent extended criteria donors, at risk of morbidity and mortality. A retrospective study of all Alfred Hospital DCDD and DNDD (donation after neurologic determination of death) PAH LTx was undertaken. Protocolized fluid/inotrope/ventilator and extracorporeal membrane oxygenation (ECMO) strategies were utilized. Since our first DCDD LTx in 2006, 512 LTx have been performed. Of 31 PAH recipients, 11 received DCDD lungs (11% of DCDD LTx) and 20 received DNDD lungs (5% of DNDD LTx) (p = 0.04). Only one PAH patient died on the LTx waiting list. Peri-LTx ECMO was utilized in 3/11 (27%) DCDD and 6/20 (30%) DNDD PAH LTx (p = 0.68). Primary graft dysfunction, intensive care, and overall stay were the same in both groups. Survival at 1 and 8 years was 100% and 80% for DCDD versus 100% and 70% for DNDD LTx (p = 0.88), respectively. In conclusion, excellent results can be achieved for PAH LTx. DCDD donor lungs are not extended lungs per se having passed the toughest test.

Evolving practice: X-linked agammaglobulinemia and lung transplantation.

X-linked agammaglobulinemia (XLA) is a rare primary humoral immunodeficiency syndrome characterized by agammaglobulinemia, recurrent infections and bronchiectasis. Despite the association with end-stage bronchiectasis, the literature on XLA and lung transplantation is extremely limited. We report a series of 6 XLA patients with bronchiectasis who underwent lung transplantation. Short-term outcomes were excellent however long-term outcomes were disappointing with a high incidence of pulmonary sepsis and chronic lung allograft dysfunction (CLAD).

A randomized, double-blind, placebo-controlled, multicenter study of rabbit ATG in the prophylaxis of acute rejection in lung transplantation.

ATG-Fresenius S (ATG-F) is a polyclonal anti-human-T-lymphocyte immunoglobulin preparation that has been clinically developed to prevent episodes of acute cellular rejection. This study evaluated the efficacy and safety of ATG-F at doses of 5 and 9 mg/kg versus placebo in adult recipients of a primary lung allograft. The primary efficacy composite end point was defined as death, graft loss, acute rejection and/or loss to follow-up within 12 months of transplantation. The interim analysis showed the ATG-F 5 mg/kg treatment to be inefficacious, and it would be impossible to enroll enough patients to power the study to show a difference between the 9 mg/kg arm and the placebo arm. Therefore, the main focus of the study shifted to the safety end points and a descriptive analysis of the primary end point. At 12 months posttransplant, the efficacy failure rate was not significantly different between the ATG-F 9 mg/kg group and the placebo group (40.2% vs. 36.7%, respectively). This large study did not demonstrate a significant reduction in acute cellular rejection, graft loss or death with single-dose induction therapy with ATG-F within the first year after lung transplantation.

Lung transplantation as rescue therapy in patients too sick to be discharged from acute care.

BACKGROUND: There is an increasing demand for lung transplantation in patients in advanced respiratory failure. Although many of these patients do not require mechanical ventilation or extracorporeal membrane oxygenation, an increasing number are critically ill. In this single-center study, we have analyzed our experience with lung transplantation in subjects who were inpatients at the time of their transplant and not expected to survive to discharge. METHODS: Between July 2006 and March 2012, we performed 274 bilateral sequential lung transplants and 34 single-lung transplants. Twenty-six patients who were inpatients at the time of their transplant, and were not expected to survive to hospital discharge, formed the inpatient group in this retrospective review. The remaining 281 outpatient lung transplant patients formed the comparison group. RESULTS: The inpatient group spent significantly fewer days on the waiting list compared to the outpatient group. Postoperative survival was significantly poorer in the inpatient group compared to the outpatient group (P = .001), and this was most noticeable in the first 90 days. There was no significant difference in survival between the inpatient transplant cohort and a historically comparable wait list cohort (P = .614). CONCLUSION: Lung transplantation in critically ill inpatients, although associated with a survival advantage compared to not transplanting them, does give poorer survival results compared to postoperative survival in outpatient patients.

Diabetes is a major risk factor for mortality after lung transplantation.

Survival following lung transplant (LTx) remains significantly lower than after other solid organ transplants. Diabetes mellitus (DM) is a mortality risk factor not comprehensively studied in LTx recipients. Notably, neither the relation of time of DM onset to survival nor the actual causes of DM-associated excess mortality have been described. We determined DM status, DM diagnosis date and all-cause mortality in 386 consecutive adults who underwent LTx at our institution from January 1, 2001 to July 31, 2010. The relationship of DM to survival both as a categorical and time-dependent variable was studied. Fifty-three percent of patients had DM. Overall median survival was 5.2 (95% CI 3.8-6.6) years. At study end, 52% of patients had died, of whom 64% had DM. Estimated median survival was 10 years in patients without DM, 5.0 (3.3-6.8) years in patients with DM pre- and post-LTx and 4.3 (3.1-5.5) years in patients with new onset DM. As a time-dependent covariate, DM was the strongest risk factor for mortality, hazard ratio 3.96 (2.85-5.51). Bronchiolitis obliterans syndrome was the main cause of death in all patients surviving >90 days, but its incidence was not increased in patients with DM. Further studies are warranted to determine whether improved glycemic control could improve outcomes in LTx recipients.

Patients' expectations and experiences of rehabilitation following lung transplantation.

INTRODUCTION: Exercise rehabilitation is a key element of care following lung transplantation; however, little is known about the patients' experience of rehabilitation, or whether it meets the needs of this complex patient group. This qualitative study explored patients' expectations of a supervised exercise rehabilitation program following lung transplantation. METHODS: Participants undertook two semi-structured interviews, one before and one after the rehabilitation program. Interviews were digitally recorded, and themes were developed using line-by-line iterative thematic analysis and grounded theory. RESULTS: Eighteen adults (11 females) with mean age of 52 participated in a mean of 26 sessions of exercise training. Themes were (i) desire for normalcy including resuming family roles and performing everyday activities; (ii) the importance of rehabilitation as the mechanism for how this transformation occurred; (iii) the benefits of exercising in a group setting; and (iv) the limitations on rehabilitation that were imposed by comorbidities, either existing pre-transplant or occurring as a postoperative sequelae. CONCLUSION: Post-transplant exercise rehabilitation was perceived as a highly valuable tool that assisted recipients to return to "normal life." Group exercise was motivational, offered peer support, and therefore was advantageous to assist patients to achieve their desired physical performance level following transplantation.

Preemptive treatment with voriconazole in lung transplant recipients.

BACKGROUND: Invasive fungal infection (IFI) is associated with high mortality in lung transplant (LTx) recipients. Data for voriconazole use in preemptive treatment remain scant. METHOD: A single-center, retrospective cohort study was conducted to investigate the efficacy and safety of voriconazole preemptive treatment for post-LTx colonization. RESULTS: We reviewed 62 adult LTx patients, who received their first course of voriconazole prophylaxis (i.e., as preemptive treatment) between July 2003 and June 2010. Outcomes were determined at 6 and 12 months after commencing therapy. Aspergillus fumigatus (75.8%) was the most common colonizing isolate. Median duration of voriconazole prophylaxis was 85 days. At 6 months, 1 LTx patient (1.6%) had IFI, 47 (75.8%) cleared their colonizing isolate, 3 (4.8%) had persistent colonization, 7 (11.3%) had recurrent colonization, 1 (1.6%) had new colonization, 2 (3.2%) had aspergilloma, and 1 (1.6%) was clinically unstable with no culture results. Sixteen (25.8%) had died by 12 months. Ten (16.1%) had likely drug-related hepatotoxicity. LTx patients with diabetes mellitus within 30 days before commencing prophylaxis were at higher risk of recurrent Aspergillus colonization at 6 months (P = 0.030). Chronic rejection within 30 days before prophylaxis was associated with 12-month mortality (P = 0.007). CONCLUSIONS: Voriconazole preemptive treatment resulted in low incidence of IFI and IFI-related mortality.

Lessons and insights from ABO-incompatible lung transplantation.

With ABO blood group incompatibility (ABOi) between donor and recipient becoming a part of mainstream living-donor renal transplantation, the applicability of ABOi to other areas of transplantation is being reconsidered. Here we present a case of inadvertent ABOi lung retransplantation managed successfully with initial plasmapheresis, antithymocyte globulin and intravenous immunoglobulin; and subsequently with oral cyclophosphamide and sirolimus in addition to tacrolimus and prednisolone. Interestingly, in the setting of solid levels of tacrolimus and sirolimus, the patient developed a fatal thrombotic microangiopathy of uncertain origin subsequent to the cessation of cyclophosphamide at 9 years posttransplant. It is apparent that ABOi lung transplantation can result in surprisingly successful long-term outcomes. Low pretransplant antibody titers likely aid this and, in pediatric neonatal or infant cases, this may not be uncommon. We must proceed cautiously as there are significant risks. Understanding the monitoring, prevention and treatment of lung transplant antibody-mediated rejection, while avoiding the long-term complications of overimmunosuppression, will be the keys to the success of future cases.

Quantification of voriconazole in human bronchoalveolar lavage fluid using high-performance liquid chromatography with fluorescence detection.

The quantification of voriconazole concentration in lung epithelial lining fluid to facilitate the management of pulmonary fungal colonisation or aspergillosis is of increasing interest. An accurate and reproducible high-performance liquid chromatography method to quantify voriconazole in human bronchoalveolar lavage (BAL) fluid was developed and validated. BAL samples were concentrated by freeze-drying and reconstituted with water prior to deproteinisation. Separation was achieved with a C18 column employing fluorescence detection (excitation: 260nm, emission: 370nm). The calibration curves were linear from 2.5 to 500ng/mL. The intra- and inter-day precisions were within 7%. Accuracies ranged from 102% to 107%. The clinical applicability was established by successful measurement of voriconazole concentrations in lung transplant recipients. The assay provides an alternative approach for those with negligible access to liquid chromatography-tandem mass spectrometry instrumentation.