Changing patterns in lung transplant for respiratory failure due to COVID-19 in the U.S

Many patients with severe COVID-19 have been affected by acute respiratory distress syndrome, which has been associated with increased mortality, and up to 31% of these survivors had persistent interstitial lung abnormalities with impaired lung function and quality of life even after 6 to 24 months after initial disease. Lung transplantation quickly emerged as a viable therapy for select patients with respiratory failure due to COVID-19 by mid-2020. In this report, we identified 477 patients who underwent lung transplantation for COVID-19 in the U.S. between March 2020 and December 2022. The number of patients waitlisted and undergoing lung transplantation for COVID-19 increased steadily in the early part of the pandemic with a peak of 97 patients waitlisted between October and December 2021, before steadily decreasing since. Notably, the procedure is now increasingly being done for survivors of COVID-19 with pulmonary fibrosis, rather than for refractory ARDS patients. The 1-year post-transplant mortality was 13.7%.

Development of the Lung Transplant Frailty Scale (LT-FS)

BACKGROUND

Existing measures of frailty developed in community dwelling older adults may misclassify frailty in lung transplant candidates. We aimed to develop a novel frailty scale for lung transplantation with improved performance characteristics.

METHODS

We measured the short physical performance battery (SPPB), fried frailty phenotype (FFP), Body Composition, and serum Biomarkers representative of putative frailty mechanisms. We applied a 4-step established approach (identify frailty domain variable bivariate associations with the outcome of waitlist delisting or death; build models sequentially incorporating variables from each frailty domain cluster; retain variables that improved model performance ability by c-statistic or AIC) to develop 3 candidate "Lung Transplant Frailty Scale (LT-FS)" measures: 1 incorporating readily available clinical data; 1 adding muscle mass, and 1 adding muscle mass and research-grade Biomarkers. We compared construct and predictive validity of LT-FS models to the SPPB and FFP by ANOVA, ANCOVA, and Cox proportional-hazard modeling.

RESULTS

In 342 lung transplant candidates, LT-FS models exhibited superior construct and predictive validity compared to the SPPB and FFP. The addition of muscle mass and Biomarkers improved model performance. Frailty by all measures was associated with waitlist disability, poorer HRQL, and waitlist delisting/death. LT-FS models exhibited stronger associations with waitlist delisting/death than SPPB or FFP (C-statistic range: 0.73-0.78 vs. 0.57 and 0.55 for SPPB and FFP, respectively). Compared to SPPB and FFP, LT-FS models were generally more strongly associated with delisting/death and improved delisting/death net reclassification, with greater improvements with increasing LT-FS model complexity (range: 0.11-0.34). For example, LT-FS-Body Composition hazard ratio for delisting/death: 6.0 (95%CI: 2.5, 14.2), SPPB HR: 2.5 (95%CI: 1.1, 5.8), FFP HR: 4.3 (95%CI: 1.8, 10.1). Pre-transplant LT-FS frailty, but not SPPB or FFP, was associated with mortality after transplant.

CONCLUSIONS

The LT-FS is a disease-specific physical frailty measure with face and construct validity that has superior predictive validity over established measures.

Subphenotypes of frailty in lung transplant candidates

Heterogeneous frailty pathobiology might explain the inconsistent associations observed between frailty and lung transplant outcomes. A Subphenotype analysis could refine frailty measurement. In a 3-center pilot cohort study, we measured frailty by the Short Physical Performance Battery, body composition, and serum biomarkers reflecting causes of frailty. We applied latent class modeling for these baseline data. Next, we tested class construct validity with disability, waitlist delisting/death, and early postoperative complications. Among 422 lung transplant candidates, 2 class model fit the best (P = .01). Compared with Subphenotype 1 (n = 333), Subphenotype 2 (n = 89) was characterized by systemic and innate inflammation (higher IL-6, CRP, PTX3, TNF-R1, and IL-1RA); mitochondrial stress (higher GDF-15 and FGF-21); sarcopenia; malnutrition; and lower hemoglobin and walk distance. Subphenotype 2 had a worse disability and higher risk of waitlist delisting or death (hazards ratio: 4.0; 95% confidence interval: 1.8-9.1). Of the total cohort, 257 underwent transplant (Subphenotype 1: 196; Subphenotype 2: 61). Subphenotype 2 had a higher need for take back to the operating room (48% vs 28%; P = .005) and longer posttransplant hospital length of stay (21 days [interquartile range: 14-33] vs 18 days [14-28]; P = .04). Subphenotype 2 trended toward fewer ventilator-free days, needing more postoperative extracorporeal membrane oxygenation and dialysis, and higher need for discharge to rehabilitation facilities (P ≤ .20). In this early phase study, we identified biological frailty Subphenotypes in lung transplant candidates. A hyperinflammatory, sarcopenic Subphenotype seems to be associated with worse clinical outcomes.

Common Noninfectious Complications Following Lung Transplantation

According to the Scientific Registry of Transplant Recipients, both transplant volume and survival among lung transplant recipients are improving over time. However, the outcomes of lung transplantation remain challenged by multiple thoracic and extrathoracic complications. With improving lung transplant survival, patients experience prolonged exposure to chronic immunosuppressive agents that can lead to multiple infectious and noninfectious complications. This article focuses on most common noninfectious complications with significant clinical impact.

Quality of Life Outcomes and Associated Symptoms Reported by Lung Transplant Recipients Amidst COVID-19 Pandemic: Applying a Novel Assessment Tool

BACKGROUND

There are 2 main aims of lung transplantation for people with end-stage lung disease: (1) to extend life and (2) to improve its quality. Much consideration is given to how to support the longevity and functioning of the allograft, though less robust studies have been done on the quality of the recipients' lives. With an interest in providing compassionate and holistic patient-centered care, it is vital that the treatment providers accurately understand their patients' lived experience. This study aimed to describe the health-related quality of life experiences of lung transplant recipients. An interest was held for where patients may struggle, thus informing where support might be needed to achieve the best possible outcomes.

METHODS

This single-center study used a validated Lung Transplant Quality of Life questionnaire, which was sent in autumn of 2020 to all of the lung transplant recipients (n = 581) under the care of Columbia University Irving Medical Center (New York, NY).

RESULTS

"Anxiety/Depression" had the highest concentration of struggle responses, followed closely by "Pulmonary Symptoms" and "Neuromuscular Symptoms." "Neuromuscular Problems" and "Sexual Problems" had the highest percentage of struggle responses. As the struggles increased, the overall quality of life rating dropped proportionately. There was no correlation between the overall quality of life and graft dysfunction, age, or time out from transplant date. All of the domains held an average rating of "Satisfactory," except "Treatment Burden," which was rated as "Favorable." Those ratings dropped for the cohort of patients who died during the study period.

CONCLUSIONS

With the goal of providing comprehensive care at the forefront of transplant priorities, we found the newly developed questionnaire invaluable in targeting areas for quality improvements, mostly notably respecting recipient mental health.

Nonallograft Complications of Lung Transplantation

Long-term exposure to immunosuppressive therapy may exacerbate pre-existing medical comorbidities or result in the development of new chronic medical conditions after lung transplantation. This article focuses on common nonallograft complications with the highest impact on short- and long-term outcomes after transplantation. These include diabetes mellitus, hypertension, dyslipidemia, kidney disease (acute and chronic), and malignancy. We discuss evidence-based strategies for the prevention, diagnosis, and management of these nonallograft complications in this article.

The new allocation era and policy

Since the Department of Health and Human Services (DHHS) issued the Final Rule in 1998 as a guideline for organ transplantation and allocation policies, the lung allocation system has undergone two major changes. The first change came with the implementation of the lung allocation score (LAS) instead of waiting time as the primary determinant for donor lung allocation. The LAS model helped allocate donor lungs based on medical urgency and likelihood of post-transplant success. The LAS has been successful in prioritizing the sickest candidates and reducing waitlist mortality in line with the Final Rule mandates. However, the LAS model did not address geographic variability in donor lung supply and demand, leading to disparities in waiting list survival based on a patient’s listing location, which was inconsistent with the Final Rule. In an urgent response to a lawsuit filed by a patient demanding broader geographic access to lungs in November 2017, the second major change in lung allocation occurred when the primary allocation unit for donor lungs expanded from the local donation service area (DSA) to a 250-nautical mile radius around the donor hospital. The Organ Procurement and Transplantation Network has since undergone a review of the current organ allocation systems and has approved a continuous organ distribution framework to guide the creation of a new organ allocation system without rigid geographic borders. In this review, we will describe the history of lung allocation, the changes to the allocation system and their consequences, and the potential future of lung allocation policy in the U.S.

Malakoplakia Presenting as a Lung Mass in a Lung Transplant Recipient: Case Report

Lung nodules or masses due to a variety of malignant or benign conditions such as opportunistic infections are observed after lung transplant. Malakoplakia is a rare complication in immunocompromised patients. Here we describe the clinical course and management of a lung transplant recipient with pulmonary malakoplakia and provide a review of the literature. To our knowledge, this is the first report of a case of pulmonary malakoplakia due to Escherichia coli infection in a lung allograft.

Geographic disparities in lung transplantation in the United States before and after the November 2017 allocation change

BACKGROUND

The primary lung allocation unit was expanded from the donation service area to a 250-mile radius in 2017. Prior to the change, geographic disparities in donor lung availability impacted waitlist outcomes. We sought to determine if the new allocation system improved these disparities.

METHODS

We conducted a retrospective cohort study comparing the 2-year period before and after the change. Donor lung availability was defined as the ratio of donor lungs to waitlist candidates in the primary allocation unit. Transplant centers were divided into quartiles by donor lung availability. Multivariable competing risk models were used to determine the association between lung availability and waitlist outcomes. Multivariable Cox proportional hazards models compared post-transplant survival.

RESULTS

Prior to the allocation change, the unadjusted transplant rate at centers in the lowest and highest quartiles was 132 and 607 transplants per 100 waitlist years. Candidates in the lowest quartile of donor lung availability had a 61% adjusted lower transplantation rate compared to candidates in highest quartile (sub-hazard ratio [sHR]: 0.39, 95% confidence interval [CI]: 0.34-0.44). After the allocation change, the disparity decreased resulting in an unadjusted transplant rate of 141 and 309 among centers in the lowest and highest quartiles. Candidates in the lowest quartile had a 38% adjusted lower transplantation rate compared to those in the highest (sHR: 0.62, 95% CI: 0.57-0.68). There was no significant difference in 1-year post-transplant survival.

CONCLUSIONS

Although the expansion of the primary allocation unit improved disparities in waitlist outcomes without any change in post-transplant survival, there still remain significant differences due to geography.

What Awaits on the Other Side: Post-Lung Transplant Morbidity and Mortality After Pre-Transplant Hospitalization

Background

Morbidity and mortality rates after lung transplantation remain high compared to other solid organ transplants. In the lung allocation score era, patients given the highest priority on the waitlist are those with the greatest severity of illness, who often require preoperative hospitalization.

Material/Methods

To determine the association of pre-transplant hospitalization with post-transplant outcomes, we retrospectively evaluated 448 lung transplant recipients at our center between January 2010 and July 2017 (114 hospitalized; 334 outpatient).

Results

Survival was similar between the groups (hazard ratio 0.93 [95% CI 0.61 to 1.42], p=0.738). However, hospitalized patients had longer hospital and intensive care unit length of stay compared to outpatients – 25 vs. 18 days, (p<0.001) and 9.5 vs. 6 days, (p<0.001), respectively. Hospitalized patients had higher rates of Grade 3 primary graft dysfunction – 29.8% vs. 9.6%, p<0.001 – and remained mechanically ventilated longer – 6 vs. 3 days, p<0.001. A greater percentage of hospitalized patients needed a tracheostomy and a re-operation within 30 days – 39.5% vs. 15.3% (p<0.001) and 22.8% vs. 12.0% (p=0.005) – respectively. After discharge, 28% of hospitalized patients required acute rehabilitation compared with 12% of outpatients (p=0.001).

Conclusions

While pre-transplant hospitalization is not associated with mortality, it is associated with significant morbidity after transplant.

Minimally invasive central venoarterial extracorporeal membrane oxygenation for long-term ambulatory support as a bridge to heart-lung transplant

Extracorporeal membrane oxygenation (ECMO) is becoming a key tool for bridge to heart, lung, or heart-lung transplantation, and ambulatory ECMO support offers many advantages to prepare the patients. We here present a case of successful en bloc heart and lung transplantation after long-term ambulatory support with a minimally invasive central venoarterial ECMO approach as bridge to transplant.

Right single lung transplantation or double lung transplantation compared with left single lung transplantation in chronic obstructive pulmonary disease

BACKGROUND

Although single and double lung transplantation outcomes for chronic obstructive pulmonary disease (COPD) have been investigated, right and left single lung transplants have never been rigorously compared to evaluate disease-specific differences. Single lung transplants for COPD often have hyperinflation of the contralateral native lung, which may be more pronounced in left lung transplants.

METHODS

Using the United Network for Organ Sharing registry, we conducted a retrospective cohort study of 5,585 adults who underwent lung transplantation for COPD from May 4, 2005 to June 30, 2017. Subjects were followed until March 2019. Post-transplant survival was compared using Cox proportional hazards and Royston and Parmar's flexible parametric survival models. We adjusted for donor and recipient factors with known or plausible associations with survival.

RESULTS

Lung transplant recipients who received a left single lung transplant for COPD had an increased risk of post-transplant death when compared with those who received a right single lung transplant for COPD (hazard ratio [HR]: 1.24, 95% CI: 1.08-1.48, p = 0.002). Survival did not differ significantly between double lung transplant and right single lung transplant recipients (HR: 0.88, 95% CI: 0.77-1.02, p = 0.086). Adjusted 5-year survival was 57.8% (95% CI: 55.7-60.1) for double lung recipients, 56.7% (95% CI: 55.4-58.0) for right single lung recipients, and 50.9% (95% CI: 47.2-55.0) for left single lung recipients.

CONCLUSIONS

In COPD, right single lung transplantation was associated with improved post-transplant survival compared with left single lung transplantation, and no significant difference in post-transplant survival compared with double lung transplantation was found. In light of the ongoing donor lung shortage, preferential allocation of right single lungs to patients with COPD should be considered.

Characteristics and outcomes of lung cancer in solid organ transplant recipients

OBJECTIVES

Lung cancer is the third most common malignancy that develops in patients following solid organ transplantation and is the leading cause of cancer deaths in the general population. The aims of this study are to examine the characteristics of patients who developed lung cancer following solid organ transplantation at our institution and to compare their outcomes to those of lung cancer patients without a history of transplant.

MATERIALS AND METHODS

We performed a single-institution retrospective study of 44 solid organ transplant recipients who developed lung cancer and compared their characteristics to a cohort of 74 lung cancer patients without a history of transplant. We performed propensity score weighted analyses to compare outcomes between the two groups, including a cox proportional hazards model of overall survival.

RESULTS

52 % of post-transplant patients who developed lung cancer were diagnosed with stage III or IV disease. In the propensity score weighted analysis that accounted for age at diagnosis, sex, lung cancer stage at diagnosis, Charlson comorbidity index score, and ECOG performance score, post-transplant patients were more likely to have squamous cell histology (p < 0.01) and had worse overall survival compared to the non-transplant cohort (HR = 1.88, 95 % CI 1.13-3.12, p = 0.02). The difference in survival remained significant after accounting for differences in lung cancer histology and treatment (HR = 2.40, 95 % CI 1.27-3.78, p < 0.01).

CONCLUSIONS

When compared to non-transplant patients with lung cancer, post-transplant patients have worse overall survival after accounting for differences in age, sex, lung cancer stage, comorbidities, and performance status. This survival difference is not solely attributable to differences in tumor histology and treatments received. This may suggest that post-transplant malignancies are more aggressive and difficult to treat.

Effect of Calculated Panel Reactive Antibody Value on Waitlist Outcomes for Lung Transplant Candidates

Background

We conducted a retrospective cohort study using United Network of Organ Sharing (UNOS) data to determine the effect of the calculated panel reactive antibody (cPRA) value on waitlist outcomes for lung transplant candidates.

Material/Methods

We divided lung transplant candidates into groups based on their cPRA value at the time of waitlist activation (0–25%, 25.1–50%, 50.1–75%, and 75.1–100%) and compared each group’s waitlist outcomes to the lowest quartile (“minimally sensitized”) group. The primary outcome was lung transplantation and the secondary outcome was waitlist mortality (a composite of death on the waitlist/delisting for clinical deterioration).

Results

Compared to the minimally sensitized group, candidates with a cPRA value of 25.1–50% did not have a significantly different likelihood of undergoing lung transplant or waitlist mortality, candidates with a cPRA value of 50.1–75% were 25% less likely to undergo lung transplant and 44% more likely to die on the waitlist, and candidates with a cPRA value of 75.1–100% were 52% less likely to undergo lung transplant and 92% more likely to die on the waitlist.

Conclusions

CPRA values of greater than 50% are associated with significantly lower rates of transplantation and higher waitlist mortality.

Frailty phenotypes and mortality after lung transplantation: A prospective cohort study

Frailty is associated with increased mortality among lung transplant candidates. We sought to determine the association between frailty, as measured by the Short Physical Performance Battery (SPPB), and mortality after lung transplantation. In a multicenter prospective cohort study of adults who underwent lung transplantation, preoperative frailty was assessed with the SPPB (n = 318) and, in a secondary analysis, the Fried Frailty Phenotype (FFP; n = 299). We tested the association between preoperative frailty and mortality following lung transplantation with propensity score-adjusted Cox models. We calculated postestimation marginalized standardized risks for 1-year mortality by frailty status using multivariate logistic regression. SPPB frailty was associated with an increased risk of both 1- and 4-year mortality (adjusted hazard ratio [aHR]: 7.5; 95% confidence interval [CI]: 1.6-36.0 and aHR 3.8; 95%CI: 1.8-8.0, respectively). Each 1-point worsening in SPPB was associated with a 20% increased risk of death (aHR: 1.20; 95%CI: 1.08-1.33). Frail subjects had an absolute increased risk of death within the first year after transplantation of 12.2% (95%CI: 3.1%-21%). In secondary analyses, FFP frailty was associated with increased risk of death within the first postoperative year (aHR: 3.8; 95%CI: 1.1-13.2) but not over longer follow-up. Preoperative frailty is associated with an increased risk of death after lung transplantation.

Geographic disparities in donor lung supply and lung transplant waitlist outcomes: A cohort study

Despite the Final Rule mandate for equitable organ allocation in the United States, geographic disparities exist in donor lung allocation, with the majority of donor lungs being allocated locally to lower-priority candidates. We conducted a retrospective cohort study of 19 622 lung transplant candidates waitlisted between 2006 and 2015. We used multivariable adjusted competing risk survival models to examine the relationship between local lung availability and waitlist outcomes. The primary outcome was a composite of death and removal from the waitlist for clinical deterioration. Waitlist candidates in the lowest quartile of local lung availability had an 84% increased risk of death or removal compared with candidates in the highest (subdistribution hazard ratio [SHR]: 1.84, 95% confidence interval [CI]: 1.51-2.24, P < .001). The transplantation rate was 57% lower in the lowest quartile compared with the highest (SHR: 0.43, 95% CI: 0.39-0.47). The adjusted death or removal rate decreased by 11% with a 50% increase in local lung availability (SHR: 0.89, 95% CI: 0.85-0.93, P < .001) and the adjusted transplantation rate increased by 19% (SHR: 1.19, 95% CI: 1.17-1.22, P < .001). There are geographically disparate waitlist outcomes in the current lung allocation system. Candidates listed in areas of low local lung availability have worse waitlist outcomes.

New frontiers in immunosuppression

Immunosuppressive therapy is arguably the most important component of medical care after lung transplantation. The goal of immunosuppression is to prevent acute and chronic rejection while maximizing patient survival and long-term allograft function. However, the benefits of immunosuppressive therapy must be balanced against the side effects and major toxicities of these medications. Immunosuppressive agents can be classified as induction agents, maintenance therapies, treatments for acute rejection and chronic rejection and antibody directed therapies. Although induction therapy remains an area of controversy in lung transplantation, it is still used in the majority of transplant centers. On the other hand, maintenance immunosuppression is less contentious; but, unfortunately, since the creation of three-drug combination therapy, including a glucocorticoid, calcineurin inhibitor and anti-metabolite, there have been relatively modest improvements in chronic maintenance immunosuppressive regimens. The presence of HLA antibodies in transplant candidates and development of de novo antibodies after transplantation remain a major therapeutic challenge before and after lung transplantation. In this chapter we review the medications used for induction and maintenance immunosuppression along with their efficacy and side effect profiles. We also review strategies and evidence for HLA desensitization prior to lung transplantation and management of de novo antibody formation after transplant. Finally, we review immune tolerance and the future of lung transplantation to limit the toxicities of conventional immunosuppressive therapy.

Extracorporeal Life Support in Lung Transplantation

Extracorporeal life support in lung transplantation has been associated with poor posttransplant outcomes. However, recent advances have resulted in more favorable posttransplant outcomes. The increased use of this technology must be weighed against the risks inherent in its use, especially when complications arising in extracorporeal membrane oxygenation (ECMO)-dependent patients result in loss of transplant candidacy, leaving them with no viable alternative for long-term support. Existing and emerging data support the judicious use of this technology in carefully selected patients at high-volume transplant and ECMO centers that prioritize minimization of sedation, avoidance of endotracheal intubation, and early mobilization.

Frailty and maximal exercise capacity in adult lung transplant candidates

BACKGROUND

Frail lung transplant candidates are more likely to be delisted or die without receiving a transplant. Further knowledge of what frailty represents in this population will assist in developing interventions to prevent frailty from developing. We set out to determine whether frail lung transplant candidates have reduced exercise capacity independent of disease severity and diagnosis.

METHODS

Sixty-eight adult lung transplant candidates underwent cardiopulmonary exercise testing (CPET) and a frailty assessment (Fried's Frailty Phenotype (FFP)). Primary outcomes were peak workload and peak aerobic capacity (V˙O₂). We used linear regression to adjust for age, gender, diagnosis, and lung allocation score (LAS).

RESULTS

The mean ± SD age was 57 ± 11 years, 51% were women, 57% had interstitial lung disease, 32% had chronic obstructive pulmonary disease, 11% had cystic fibrosis, and the mean LAS was 40.2 (range 19.2-94.5). In adjusted models, peak workload decreased by 10 W (95% CI 4.7 to 14.6) and peak V˙O₂ decreased by 1.8 mL/kg/min (95% CI 0.6 to 2.9) per 1 unit increment in FFP score. After adjustment, exercise tolerance was 38 W lower (95% CI 18.4 to 58.1) and peak V˙O₂ was 8.5 mL/kg/min lower (95% CI 3.3 to 13.7) among frail participants compared to non-frail participants. Frailty accounted for 16% of the variance (R²) of watts and 19% of the variance of V˙O₂ in adjusted models.

CONCLUSION

Frailty contributes to reduced exercise capacity among lung transplant candidates independent of disease severity.

Cardiopulmonary exercise factors predict survival in patients with advanced interstitial lung disease referred for lung transplantation

BACKGROUND

The purpose of this work was to determine if parameters assessed during Cardiopulmonary Exercise Testing (CPET) while using supplemental oxygen can independently predict one-year transplant-free survival in patients with Interstitial Lung Disease (ILD) referred for lung transplant evaluation.

METHODS

We performed a chart review of patients with ILD who completed CPET with 30% FiO₂ and gathered spirometry, pulmonary hemodynamic, six-minute walk, and CPET data. The primary end-point was death or lung transplantation within one-year of CPET.

RESULTS

The final data set included 192 patients. 79 patients died/underwent transplant, 113 survived transplant-free. Multivariable Cox regression revealed peak workload % predicted, nadir CPET SpO₂, and FVC% predicted as independent predictors of one-year transplant-free survival. Of the independent predictors of survival, receiver operating characteristics analysis revealed peak workload %predicted cutoff of 35% to be highly discriminatory, more so than nadir CPET SpO₂ or FVC % predicted in identifying patients at risk for one-year mortality or transplant (peak workload % predicted < 35% HR = 4.71, 95% CI = 2.64-8.38 and area under the curve (AUC) = 0.740, nadir CPET SpO₂ < 86% HR = 2.27, 95%CI = 1.41-3.68, AUC = 0.645, FVC %predicted <45% HR = 1.82, 95% CI = 1.15-2.87, AUC = 0.624).

CONCLUSION

Peak workload % predicted, nadir CPET SpO₂, and FVC% predicted in ILD patients referred for lung transplant evaluation are independently predictive of one-year mortality or need for transplant.

Frailty Phenotypes, Disability, and Outcomes in Adult Candidates for Lung Transplantation

RATIONALE

Frailty is associated with morbidity and mortality in abdominal organ transplantation but has not been examined in lung transplantation.

OBJECTIVES

To examine the construct and predictive validity of frailty phenotypes in lung transplant candidates.

METHODS

In a multicenter prospective cohort, we measured frailty with the Fried Frailty Phenotype (FFP) and Short Physical Performance Battery (SPPB). We evaluated construct validity through comparisons with conceptually related factors. In a nested case-control study of frail and nonfrail subjects, we measured serum IL-6, tumor necrosis factor receptor 1, insulin-like growth factor I, and leptin. We estimated the association between frailty and disability using the Lung Transplant Valued Life Activities disability scale. We estimated the association between frailty and risk of delisting or death before transplant using multivariate logistic and Cox models, respectively.

MEASUREMENTS AND MAIN RESULTS

Of 395 subjects, 354 completed FFP assessments and 262 completed SPPB assessments; 28% were frail by FFP (95% confidence interval [CI], 24-33%) and 10% based on the SPPB (95% CI, 7-14%). By either measure, frailty correlated more strongly with exercise capacity and grip strength than with lung function. Frail subjects tended to have higher plasma IL-6 and tumor necrosis factor receptor 1 and lower insulin-like growth factor I and leptin. Frailty by either measure was associated with greater disability. After adjusting for age, sex, diagnosis, and transplant center, both FFP and SPPB were associated with increased risk of delisting or death before lung transplant. For every 1-point worsening in score, hazard ratios were 1.30 (95% CI, 1.01-1.67) for FFP and 1.53 (95% CI, 1.19-1.59) for SPPB.

CONCLUSIONS

Frailty is prevalent among lung transplant candidates and is independently associated with greater disability and an increased risk of delisting or death.

Short Stature and Access to Lung Transplantation in the United States. A Cohort Study

RATIONALE

Anecdotally, short lung transplant candidates suffer from long waiting times and higher rates of death on the waiting list compared with taller candidates.

OBJECTIVES

To examine the relationship between lung transplant candidate height and waiting list outcomes.

METHODS

We conducted a retrospective cohort study of 13,346 adults placed on the lung transplant waiting list in the United States between 2005 and 2011. Multivariable-adjusted competing risk survival models were used to examine associations between candidate height and outcomes of interest. The primary outcome was the time until lung transplantation censored at 1 year.

MEASUREMENTS AND MAIN RESULTS

The unadjusted rate of lung transplantation was 94.5 per 100 person-years among candidates of short stature (<162 cm) and 202.0 per 100 person-years among candidates of average stature (170-176.5 cm). After controlling for potential confounders, short stature was associated with a 34% (95% confidence interval [CI], 29-39%) lower rate of transplantation compared with average stature. Short stature was also associated with a 62% (95% CI, 24-96%) higher rate of death or removal because of clinical deterioration and a 42% (95% CI, 10-85%) higher rate of respiratory failure while awaiting lung transplantation.

CONCLUSIONS

Short stature is associated with a lower rate of lung transplantation and higher rates of death and respiratory failure while awaiting transplantation. Efforts to ameliorate this disparity could include earlier referral and listing of shorter candidates, surgical downsizing of substantially oversized allografts for shorter candidates, and/or changes to allocation policy that account for candidate height.

Survival of adults with systemic sclerosis following lung transplantation: a nationwide cohort study

OBJECTIVE

Many transplant programs are hesitant to offer lung transplantation to patients with systemic sclerosis (SSc) due to concerns about extrapulmonary involvement that might affect survival. The aim of this study was to determine whether adults with SSc have higher 1-year mortality rates after lung transplantation compared to those with interstitial lung disease (ILD) or pulmonary arterial hypertension (PAH) not due to SSc.

METHODS

Using data provided by the United Network for Organ Sharing, we performed a retrospective cohort study of 229 adults with SSc, 201 with PAH, and 3,333 with ILD who underwent lung transplantation in the US between May 4, 2005 and September 14, 2012. We examined associations between diagnosis and 1-year survival after lung transplantation using stratified Cox models adjusted for recipient, donor, and procedure factors.

RESULTS

Adults with SSc undergoing lung transplantation in the US had a multivariable-adjusted 48% relative increase in the 1-year mortality rate compared to those with non-SSc-related ILD (hazard ratio 1.48 [95% confidence interval 1.01-2.17]). However, we did not detect a difference in the risk of death at 1 year between those with SSc and those with non-SSc-related PAH (hazard ratio 0.85 [95% confidence interval 0.50-1.44]).

CONCLUSION

A diagnosis of SSc may confer an increased risk of death 1 year following lung transplantation compared to a diagnosis of ILD, but this risk is similar to that of PAH, a widely accepted indication for lung transplantation. Future work should identify modifiable risk factors that can improve transplant outcomes in this population.

Body composition and mortality after adult lung transplantation in the United States

RATIONALE

Obesity and underweight are contraindications to lung transplantation based on their associations with mortality in studies performed before implementation of the lung allocation score (LAS)-based organ allocation system in the United States Objectives: To determine the associations of body mass index (BMI) and plasma leptin levels with survival after lung transplantation.

METHODS

We used multivariable-adjusted regression models to examine associations between BMI and 1-year mortality in 9,073 adults who underwent lung transplantation in the United States between May 2005 and June 2011, and plasma leptin and mortality in 599 Lung Transplant Outcomes Group study participants. We measured body fat and skeletal muscle mass using whole-body dual X-ray absorptiometry in 142 adult lung transplant candidates.

MEASUREMENTS AND MAIN RESULTS

Adjusted mortality rates were similar among normal weight (BMI 18.5-24.9 kg/m(2)), overweight (BMI 25.0-29.9), and class I obese (BMI 30-34.9) transplant recipients. Underweight (BMI < 18.5) was associated with a 35% increased rate of death (95% confidence interval, 10-66%). Class II-III obesity (BMI ≥ 35 kg/m(2)) was associated with a nearly twofold increase in mortality (hazard ratio, 1.9; 95% confidence interval, 1.3-2.8). Higher leptin levels were associated with increased mortality after transplant surgery performed without cardiopulmonary bypass (P for interaction = 0.03). A BMI greater than or equal to 30 kg/m(2) was 26% sensitive and 97% specific for total body fat-defined obesity.

CONCLUSIONS

A BMI of 30.0-34.9 kg/m(2) is not associated with 1-year mortality after lung transplantation in the LAS era, perhaps because of its low sensitivity for obesity. The association between leptin and mortality suggests the need to validate alternative methods to measure obesity in candidates for lung transplantation. A BMI greater than or equal to 30 kg/m(2) may no longer contraindicate lung transplantation.

Intravenous immunoglobulin for hypogammaglobulinemia after lung transplantation: a randomized crossover trial

Background

We aimed to determine the effects of treatment with intravenous immunoglobulin on bacterial infections in patients with hypogammaglobulinemia (HGG) after lung transplantation.

Methods

We performed a randomized, double-blind, placebo-controlled two-period crossover trial of immune globulin intravenous (IVIG), 10% Purified (Gamunex, Bayer, Elkhart, IN) monthly in eleven adults who had undergone lung transplantation more than three months previously. We randomized study participants to three doses of IVIG (or 0.1% albumin solution (placebo)) given four weeks apart followed by a twelve week washout and then three doses of placebo (or IVIG). The primary outcome was the number of bacterial infections within each treatment period.

Results

IVIG had no effect on the number of bacterial infections during the treatment period (3 during IVIG and 1 during placebo; odds ratio 3.5, 95% confidence interval 0.4 to 27.6, p = 0.24). There were no effects on other infections, use of antibiotics, or lung function. IVIG significantly increased trough IgG levels at all time points (least square means, 765.3 mg/dl during IVIG and 486.3 mg/dl during placebo, p<0.001). Four serious adverse events (resulting in hospitalization) occurred during the treatment periods (3 during active treatment and 1 during the placebo period, p = 0.37). Chills, flushing, and nausea occurred during one infusion of IVIG.

Conclusions

Treatment with IVIG did not reduce the short-term risk of bacterial infection in patients with HGG after lung transplantation. The clinical efficacy of immunoglobulin supplementation in HGG related to lung transplantation over the long term or with recurrent infections is unknown.

Trial Registration

Clinicaltrials.gov NCT00115778

Donor age and early graft failure after lung transplantation: a cohort study

Lungs from older adult organ donors are often unused because of concerns for increased mortality. We examined associations between donor age and transplant outcomes among 8860 adult lung transplant recipients using Organ Procurement and Transplantation Network and Lung Transplant Outcomes Group data. We used stratified Cox proportional hazard models and generalized linear mixed models to examine associations between donor age and both 1-year graft failure and primary graft dysfunction (PGD). The rate of 1-year graft failure was similar among recipients of lungs from donors age 18-64 years, but severely ill recipients (Lung Allocation Score [LAS] >47.7 or use of mechanical ventilation) of lungs from donors age 56-64 years had increased rates of 1-year graft failure (p-values for interaction = 0.04 and 0.02, respectively). Recipients of lungs from donors <18 and ≥65 years had increased rates of 1-year graft failure (adjusted hazard ratio [HR] 1.23, 95% CI 1.01-1.50 and adjusted HR 2.15, 95% CI 1.47-3.15, respectively). Donor age was not associated with the risk of PGD. In summary, the use of lungs from donors age 56 to 64 years may be safe for adult candidates without a high LAS and the use of lungs from pediatric donors is associated with a small increase in early graft failure.

Interobserver variability in grading transbronchial lung biopsy specimens after lung transplantation

BACKGROUND

Acute rejection remains a major source of morbidity after lung transplantation. Given the importance of this diagnosis, an international grading system was developed to standardize the diagnosis of acute lung-allograft rejection. The reliability of this grading system has not been adequately assessed by previous studies.

METHODS

We examined the level of agreement in grading transbronchial biopsy specimens obtained from a large multicenter study (AIRSAC [Comparison of a Tacrolimus/Sirolimus/Prednisone Regimen vs Tacrolimus/Azathioprine/Prednisone Immunosuppressive Regimen in Lung Transplantation] trial). Biopsy specimens were initially graded for acute rejection and lymphocytic bronchiolitis by the site pathologist and subsequently graded by a central pathologist. Reliability of interobserver grading was evaluated using Cohen κ coefficients.

RESULTS

A total of 481 transbronchial biopsy specimens were graded by both the site and central pathologists. The overall concordance rates were 74% and 89% for grade A and grade B biopsy specimens, respectively. When samples from biopsies performed at different time points after transplantation were assessed, there was a higher level of agreement early (≤ 6 weeks) after transplant compared with later time points for acute rejection. However, there was still only moderate agreement for both grade A (κ score 0.479; 95% CI, 0.29-0.67) and grade B (κ score 0.465; 95% CI, 0.08-0.85) rejection.

CONCLUSIONS

These results expand upon previous reports of interobserver variability in grading transbronchial biopsy specimens after lung transplantation. Given the variability in grading these specimens, we advocate further education of the histopathologic findings in lung transplant biopsy specimens, as well as revisiting the current criteria for grading transbronchial biopsy specimens to improve concordance among lung transplant pathologists.

TRIAL REGISTRY

ClinicalTrials.gov; No. NCT00321906; URL: www.clinicaltrials.gov.

Pulmonary arteriole gene expression signature in idiopathic pulmonary fibrosis

A third of patients with idiopathic pulmonary fibrosis (IPF) develop pulmonary hypertension (PH-IPF), which is associated with increased mortality. Whether an altered gene expression profile in the pulmonary vasculature precedes the clinical onset of PH-IPF is unknown. We compared gene expression in the pulmonary vasculature of IPF patients with and without PH with controls. Pulmonary arterioles were isolated using laser capture microdissection from 16 IPF patients: eight with PH (PH-IPF) and eight with no PH (NPH-IPF), and seven controls. Probe was prepared from extracted RNA, and hybridised to Affymetrix Hu133 2.0 Plus genechips. Biometric Research Branch array tools and Ingenuity Pathway Analysis software were used for analysis of the microarray data. Univariate analysis revealed 255 genes that distinguished IPF arterioles from controls (p<0.001). Mediators of vascular smooth muscle and endothelial cell proliferation, Wnt signalling and apoptosis were differentially expressed in IPF arterioles. Unsupervised and supervised clustering analyses revealed similar gene expression in PH-IPF and NPH-IPF arterioles. The pulmonary arteriolar gene expression profile is similar in IPF patients with and without coexistent PH. Pathways involved in vascular proliferation and aberrant apoptosis, which may contribute to pulmonary vascular remodelling, are activated in IPF patients.

Decreased incidence of cytomegalovirus infection with sirolimus in a post hoc randomized, multicenter study in lung transplantation

BACKGROUND

Cytomegalovirus (CMV) is the most common opportunistic infection in lung transplantation. A recent multicenter, randomized trial (the AIRSAC study) comparing sirolimus to azathioprine in lung transplant recipients showed a decreased incidence of CMV events in the sirolimus cohort. To better characterize this relationship of decreased incidence of CMV events with sirolimus, we examined known risk factors and characteristics of CMV events from the AIRSAC database.

METHODS

The AIRSAC database included 181 lung transplant patients from 8 U.S.-based lung transplant centers that were randomized to sirolimus or azathioprine at 3 months post-transplantation. CMV incidence, prophylaxis, diagnosis and treatment data were all prospectively collected. Prophylaxis and treatment of CMV were at the discretion of each institution.

RESULTS

The overall incidence of any CMV event was decreased in the sirolimus arm when compared with the azathioprine arm at 1 year after lung transplantation (relative risk [RR] = 0.67, confidence interval [CI] 0.55 to 0.82, p < 0.01). This decreased incidence of CMV events with sirolimus remained significant after adjusting for confounding factors of CMV serostatus and CMV prophylaxis.

CONCLUSIONS

These data support results from other solid-organ transplantation studies and suggest further investigation of this agent in the treatment of lung transplant recipients at high risk for CMV events.

Plasma monocyte chemotactic protein-1 levels at 24 hours are a biomarker of primary graft dysfunction after lung transplantation

Monocyte chemotactic protein-1 (MCP-1), also known as "chemokine ligand 2" (CCL2), is a monocyte-attracting chemokine produced in lung epithelial cells. We previously reported an association of increased levels of plasma MCP-1 with primary graft dysfunction (PGD) after lung transplantation in a nested case-control study of extreme phenotypes using a multiplex platform. In this study, we sought to evaluate the role of plasma MCP-1 level as a biomarker across the full spectrum of PGD. We performed a prospective cohort study of 108 lung transplant recipients within the Lung Transplant Outcomes Group cohort. Plasma MCP-1 levels were measured pretransplantation and 6 and 24 hours after transplantation. The primary outcome was development of grade 3 PGD within 72 hours of transplant, with secondary analyses at the 72-hour time point. Multivariable logistic regression was used to evaluate confounding. Thirty subjects (28%) developed PGD. Median MCP-1 measured at 24 hours post-transplant was elevated in subjects with PGD (167.95 vs 103.5 pg/mL, P = .04). MCP-1 levels at 24 hours were associated with increased odds of grade 3 PGD after lung transplantation (odds ratio for each 100 pg/mL, 1.24; 95% confidence interval, 1.00-1.53) and with grade 3 PGD present at the 72-hour time point (odds ratio for each 100 pg/mL, 1.57; 95% confidence interval, 1.18-2.08), independent of confounding variables in multivariable analyses. MCP-1 levels measured preoperatively and 6 hours after transplant were not significantly associated with PGD. Persistent elevations in MCP-1 levels at 24 hours are a biomarker of grade 3 PGD post-transplantation. Monocyte chemotaxis may play a role in the pathogenesis of PGD.

Obesity and primary graft dysfunction after lung transplantation: the Lung Transplant Outcomes Group Obesity Study

RATIONALE

Obesity has been linked to acute lung injury and is a risk factor for early mortality after lung transplantation.

OBJECTIVES

To examine the associations of obesity and plasma adipokines with the risk of primary graft dysfunction after lung transplantation.

METHODS

We performed a prospective cohort study of 512 adult lung transplant recipients with chronic obstructive pulmonary disease or interstitial lung disease enrolled in the Lung Transplant Outcomes Group Study. In a nested case-control study, we measured plasma leptin, adiponectin, and resistin before lung transplantation and 6 and 24 hours after lung transplantation in 40 cases of primary graft dysfunction and 80 control subjects. Generalized linear mixed models and logistic regression were used to estimate risk ratios and odds ratios.

MEASUREMENTS AND MAIN RESULTS

Grade 3 primary graft dysfunction developed within 72 hours of transplantation in 29% participants. Obesity was associated with a twofold increased risk of primary graft dysfunction (adjusted risk ratio 2.1; 95% confidence interval, 1.7-2.6). The risk of primary graft dysfunction increased by 40% (confidence interval, 30–50%) for each 5 kg/m(2) increase in body mass index after accounting for center, diagnosis, cardiopulmonary bypass, and transplant procedure. Higher plasma leptin levels were associated with a greater risk of primary graft dysfunction (sex-adjusted P = 0.02). The associations of both obesity and leptin with primary graft dysfunction tended to be stronger among those who did not undergo cardiopulmonary bypass.

CONCLUSIONS

Obesity is an independent risk factor for primary graft dysfunction after lung transplantation.

Delayed access and survival in idiopathic pulmonary fibrosis: a cohort study

RATIONALE

Idiopathic pulmonary fibrosis is often initially misdiagnosed. Delays in accessing subspecialty care could lead to worse outcomes among those with idiopathic pulmonary fibrosis.

OBJECTIVES

To examine the association between delayed access to subspecialty care and survival time in idiopathic pulmonary fibrosis.

METHODS

We performed a prospective cohort study of 129 adults who met American Thoracic Society criteria for idiopathic pulmonary fibrosis evaluated at a tertiary care center. Delay was defined as the time from the onset of dyspnea to the date of initial evaluation at a tertiary care center. We used competing risk survival methods to examine survival time and time to transplantation.

MEASUREMENTS AND MAIN RESULTS

The mean age was 63 years and 76% were men. The median delay was 2.2 years (interquartile range 1.0–3.8 yr), and the median follow-up time was 1.1 years. Age and lung function at the time of evaluation did not vary by delay. A longer delay was associated with an increased risk of death independent of age, sex, forced vital capacity, third-party payer, and educational attainment (adjusted hazard ratio per doubling of delay was 1.3, 95% confidence interval 1.03 to 1.6). Longer delay was not associated with a lower likelihood of undergoing lung transplantation.

CONCLUSIONS

Delayed access to a tertiary care center is associated with a higher mortality rate in idiopathic pulmonary fibrosis independent of disease severity. Early referral to a specialty center should be considered for those with known or suspected interstitial lung disease.

Titrated oxygen requirement and prognostication in idiopathic pulmonary fibrosis

The supplemental oxygen flow rate is a common bedside measure of gas exchange impairment. We aimed to determine whether a titrated oxygen requirement (TOR) predicted mortality in idiopathic pulmonary fibrosis (IPF). We examined 104 adults with IPF enrolled in a prospective cohort study and a validation cohort of 151 adults with a variety of interstitial lung diseases (ILDs). The TOR was defined as the lowest oxygen flow rate required to maintain an oxyhaemoglobin saturation of 96% while standing. Cox proportional hazards models and time-dependent receiver operating characteristic curves were used to examine survival time. A higher TOR was associated with a greater mortality rate independent of forced vital capacity and 6-min walk test results in IPF (adjusted hazard ratio (per 1 L·min(-1)) 1.16, 95% CI 1.06-1.27). The TOR was at least as accurate as pulmonary function and 6-min walk testing at predicting 1-yr mortality. Findings were similar in other ILDs. The TOR is a simple, inexpensive bedside measurement that aids prognostication in IPF.

Malignancies following lung transplantation

Malignancy is an important complication of thoracic organ transplantation and is associated with significant morbidity and mortality. Lung transplant recipients are at greater risk for cancer than immunocompetent persons, with cancer-specific incidence rates up to 60-fold higher than the general population. The increased risk for cancer is attributed to neoplastic properties of immunosuppressive medications, oncogenic viruses, and cancer-specific risk factors. This article addresses the epidemiology, presentation, and treatment of the most common malignancies after lung transplantation, including skin cancer, posttransplant lymphoproliferative disorder, and bronchogenic carcinoma.

Pathologic interpretation of transbronchial biopsy for acute rejection of lung allograft is highly variable

Despite the standardization of pathologic grading of acute rejection in transbronchial lung biopsies following lung transplantation, the reproducibility of pathologic diagnosis has not been adequately evaluated. To determine the interobserver variability for pathologic grading of acute rejection, 1566 biopsies from 845 subjects in the Lung Allograft Rejection Gene Expression Observational study were regraded by a pathology panel blinded to the original diagnosis and compared to the grade of acute rejection assigned by individual center pathologists. The study panel confirmed 49.1% of center pathologists' A0 grades, but upgraded 5.7% to A1 and 2.7% to grade ≥ A2 rejection; 42.5% were regraded as AX. Of 268 grade A1 samples, 21.2% were confirmed by the pathology panel; 18.7% were upgraded to ≥ A2 and 35.8% were downgraded to A0 with 24.3% being regraded as AX. Lastly, 53.5% of ≥ A2 cases were confirmed, but 15.7% were downgraded to grade A0 and 18.4% cases to A1, while 12.4% were regraded as AX. The kappa value for interobserver agreement was 0.183 (95%CI 0.147-0.220, p < 0.001). The results for B grade interpretation were similar. Suboptimal sampling is common and a high degree of variability exists in the pathologic interpretation of acute rejection in transbronchial biopsies.

Obesity and underweight are associated with an increased risk of death after lung transplantation

RATIONALE

Obesity is considered a relative contraindication to lung transplantation, based on studies that have not accounted for key confounders. Little is known about the risk of death for underweight candidates after transplantation.

OBJECTIVES

To examine the associations of pretransplant obesity and underweight with the risk of death after lung transplantation.

METHODS

We examined 5,978 adults with cystic fibrosis, chronic obstructive pulmonary disease, and diffuse parenchymal lung disease who underwent lung transplantation in the United States between 1995 and 2003. We used Cox models and generalized additive models to examine the association between pretransplant body mass index and the risk of death after lung transplantation with adjustment for donor and recipient factors.

MEASUREMENTS AND MAIN RESULTS

The median follow-up time was 4.2 years. Compared with normal weight recipients, the multivariable-adjusted rates of death were 15% higher for underweight recipients (95% confidence interval, 3 to 28%), 15% higher for overweight recipients (95% confidence interval, 6 to 26%), and 22% higher for obese recipients (95% confidence interval, 8 to 39%). These relationships persisted when stratified by diagnosis. The multivariable-adjusted population attributable fraction was 12% at 1 year and 8% at 5 years.

CONCLUSIONS

Both obesity and underweight are independent risk factors for death after lung transplantation, contributing to up to 12% of deaths in the first year after transplantation. Primary care providers and pulmonologists should promote a healthy weight for patients with lung disease long before transplantation is considered.

Tacrolimus and azathioprine versus cyclosporine and mycophenolate mofetil after lung transplantation: a retrospective cohort study

BACKGROUND

The efficacy and safety of different combinations of immunosuppressive regimens after lung transplantation are unknown.

METHODS

We examined 120 consecutive transplant recipients between July 2001 and July 2005, of whom 37 received cyclosporine and mycophenolate mofetil (Cyc/MMF) and 83 received tacrolimus and azathioprine (Tac/Aza) as the initial immunosuppressive regimen along with an interleukin-2 antagonist induction therapy. The primary outcome was the rate of histologically confirmed acute rejection.

RESULTS

The rate of acute rejection did not vary by treatment regimen (0.42 vs 0.34 episodes per 100 person-days in Cyc/MMF and Tac/Aza groups, respectively, p = 0.22). The mean cumulative lymphocytic bronchiolitis score was greater in the Cyc/MMF group (1.8 +/- 1.9) compared with the Tac/Aza group (1.2 +/- 2.0; p = 0.03). Pulmonary function at 1 year was better in the Tac/Aza group, even when adjusted for recipient age, gender, and transplant procedure. Survival and the rate of bronchiolitis obliterans syndrome did not vary by group.

CONCLUSIONS

Outcomes after lung transplantation did not meaningfully vary between those assigned to Cyc/MMF compared with Tac/Aza combined with IL-2 inhibitor induction therapy.

The modification of diet in renal disease (MDRD) and the prediction of kidney outcomes after lung transplantation

BACKGROUND

Chronic kidney disease (CKD) is prevalent after lung transplantation. This study evaluated the ability of the 24-hour urine creatinine clearance (CrCl) and the Modification of Diet in Renal Disease (MDRD) equation at the time of listing to predict CKD after lung transplantation and to determine risk factors for CKD.

METHODS

This was a retrospective cohort study of 122 patients who underwent lung transplantation at Columbia Presbyterian Medical Center between May 2002 and August 2006. The primary end point was CKD Stage 3 or higher, defined as glomerular filtration rate (GFR) </= 59 ml/min/1.73 m(2) or renal replacement therapy, for at least 3 months.

RESULTS

Patients were a mean age of 51 +/- 14 years, 55% women, and 83% non-Hispanic white. CKD developed in 62% by 1 year after lung transplantation. Older age, female gender, a diagnosis of sarcoidosis, and diabetes mellitus independently increased the risk of CKD (all p < 0.05). The MDRD equation was significantly better than CrCl at predicting CKD Stage 3 or higher at 1 year after transplantation, with an area under the receiver operating characteristic curve of 0.71 for MDRD (95% confidence interval [CI], 0.61-0.81) and 0.51 for CrCl (95% CI, 0.40-0.61) (P < 0.001).

CONCLUSIONS

Older age, female gender, and diabetes mellitus increased the risk of developing CKD after lung transplant. The MDRD estimate of GFR at listing was a better predictor of CKD than CrCl. MDRD estimates should be used during lung transplant evaluation for risk stratification for CKD.

Platelet activation in the postoperative period after lung transplantation

OBJECTIVE

During lung transplantation, cells in the pulmonary parenchyma are subjected to ischemia, hypothermic storage, and reperfusion injury. Platelets, whose granular contents include adhesion receptors, chemokines, and coactivating substances that activate inflammatory and coagulant cascades, likely play a critical role in the lung allograft response to ischemia and reperfusion. The platelet response to the pulmonary allograft, however, has never been studied. Here we report significant platelet activation immediately after lung transplantation.

METHODS

We performed a prospective cohort study comparing markers of platelet activation in patients undergoing lung transplantation and patients undergoing nontransplant thoracotomy. Plasma levels of soluble P-selectin, soluble CD40 ligand, and platelet-leukocyte conjugates were measured before surgery, after skin closure, and at 6 postoperative hours.

RESULTS

Both soluble P-selectin and soluble CD40 ligand levels increased significantly after lung transplantation but not after thoracotomy. Additionally, platelet-monocyte conjugate fluorescence was significantly higher after lung transplantation than after thoracotomy alone.

CONCLUSION

These findings suggest that platelet activation is significantly increased after lung transplantation beyond that expected from the postoperative state. The increase in circulating platelet-monocyte conjugates suggests an important interaction between platelets and inflammatory cells. Further research should examine whether platelet activation affects early graft function after lung transplantation.

Outcomes after Lung Retransplantation in the Modern Era

RATIONALE

Characteristics of and survival estimates for recipients of lung retransplantation in the modern era are unknown.

OBJECTIVES

To compare lung retransplant patients in the modern era with historical retransplant patients, to compare retransplant patients with initial transplant patients in the modern era, and to determine the predictors of the risk of death after lung retransplantation.

METHODS

We performed a retrospective cohort study of patients who underwent lung retransplantation between January 2001 and May 2006 in the United States (modern retransplant cohort). The characteristics and survival of this cohort were compared with those of patients who underwent first lung retransplantation between January 1990 and December 2000 (historical retransplant cohort) and patients who underwent initial lung transplantation between January 2001 and May 2006 (modern initial transplant cohort).

MEASUREMENTS AND MAIN RESULTS

Modern retransplant recipients (n = 205) had a lower risk of death compared with that of the historical retransplant cohort (n = 184) (hazard ratio, 0.7; 95% confidence interval, 0.5-0.9; P = 0.006). However, modern retransplant recipients had a higher risk of death than that of patients who underwent initial lung transplantation (n = 5,657) (hazard ratio, 1.3; 95% confidence interval, 1.2-1.5; P = 0.001), which appeared to be explained by a higher prevalence of certain comorbidities. Retransplantation at less than 30 days after the initial transplant procedure was associated with worse survival.

CONCLUSIONS

Outcomes after lung retransplantation have improved; however, retransplantation continues to pose an increased risk of death compared with the initial transplant procedure. Retransplantation early after the initial transplant poses a particularly high mortality risk.

Racial differences in waiting list outcomes in chronic obstructive pulmonary disease

RATIONALE

Blacks with chronic illness have poorer outcomes than whites in the United States. The health outcomes of minorities with chronic obstructive pulmonary disease (COPD) on the lung transplant waiting list have not been studied.

OBJECTIVES

To compare outcomes of black and white patients with COPD after listing for lung transplantation in the United States.

METHODS

Retrospective cohort study of all 280 non-Hispanic black and 5,272 non-Hispanic white adults 40 years and older with COPD listed for lung transplantation in the United States between 1995 and 2004.

MEASUREMENTS AND MAIN RESULTS

Blacks with COPD were more likely to have pulmonary hypertension, obesity, and diabetes; to lack private health insurance; and to live in poorer neighborhoods than whites. Blacks were less likely to undergo transplantation after listing compared with whites, despite adjustment for age, lung function, pulmonary hypertension, cardiovascular risk factors, insurance coverage, and poverty level (adjusted hazard ratio, 0.83; 95% confidence interval, 0.70-0.98; P = 0.03). This was accompanied by a greater risk of dying or being removed from the list among blacks (unadjusted hazard ratio, 1.31; 95% confidence interval, 1.05-1.63; P = 0.02).

CONCLUSIONS

After listing for lung transplantation, black patients with COPD were less likely to undergo transplantation and more likely to die or be removed from the list compared with white patients. Unequal access to care may have contributed to these differences.

Postlung Transplant Survival is Equivalent Regardless of Cytomegalovirus Match Status

BACKGROUND

The purpose of this study was to assess (1) the relationship between donor-recipient cytomegalovirus (CMV) serologic status and posttransplant survival in the current era and (2) temporal changes in posttransplant survival by CMV matching status.

METHODS

De-identified data were obtained from the United Network for Organ Sharing. Based on pretransplant CMV serologic status (+ or -) of recipients (R) and donors (D), posttransplant survival was compared among three groups: D+ /R-, D+/- /R+, and D- /R-. Primary analysis focused on transplants performed January 1, 2000 to December 31, 2004, in recipients 18 years of age or older. To assess temporal trends in survival among groups, all lung transplants occurring between January 1, 1990, and December 31, 2004, were considered and divided into three periods based on transplant year: 1990 through 1994, 1995 through 1999, and 2000 through 2004. The primary outcome measure was survival, reported as rate of death per 100 patient-years. Kaplan-Meier analysis with log-rank test was used for time-to-event analysis.

RESULTS

During the current era (2000 through 2004), D+ /R- (n = 951), D+/- /R+ (n = 2,676), and D- /R- (n = 772) exhibited no differences in survival (p = 0.561), with rates of death per 100 patient-years of 16.6 (95% confidence interval, 14.9 to 18.5), 15.0 (95% confidence interval, 14.0 to 16.0), and 14.7 (95% confidence interval, 13.0 to 16.6), respectively. However, survival was significantly different for groups in the earlier eras of 1990 through 1994 (p < 0.001) and 1995 through 1999 (p < 0.001). During the three periods, survival improved significantly in D+ /R- (p < 0.001) and D+/- /R+ (p < 0.001), but survival in D- /R- (p = 0.351) did not change significantly with time.

CONCLUSIONS

In the current era, survival after lung transplantation is statistically equivalent regardless of CMV match status. Although in previous eras survival was worse among the D+/- /R+ and D+ /R- groups, in this era of aggressive CMV prophylaxis, CMV mismatch should not be sufficient grounds to decline a lung allograft offer.

Update in Surgical Therapy for Chronic Obstructive Pulmonary Disease

Bullectomy for giant bullae, lung volume reduction surgery, and lung transplantation are three surgical therapies that may benefit highly selected patients with advanced chronic obstructive pulmonary disease. In this article, each procedure is reviewed, with an emphasis on guidelines for patient selection and clinical outcomes for the practicing pulmonologist. Recent results from the National Emphysema Treatment Trial, updated International Society for Heart and Lung Transplantation Registry data, and revised guidelines for patient selection for lung transplantation are discussed.