Results of Lung Transplantation for Cystic Fibrosis With Selected Donors Over 65 Years Old.

Lung transplantation is limited by the shortage of suitable donors. Many programs have begun to use extended criteria donors. Donors over 65 years old are rarely reported, especially for young cystic fibrosis recipients. This monocentric study was conducted for cystic fibrosis recipients from January 2005 to December 2019, comparing two cohorts according to lung donor age (<65 years or ≥65 years). The primary objective was to assess the survival rate at 3 years using a Cox multivariable model. Of the 356 lung recipients, 326 had donors under 65 years, and 30 had donors over 65 years. Donors' characteristics did not differ significantly in terms of sex, time on mechanical ventilation before retrieval, and partial pressure of arterial oxygen/fraction of inspired oxygen ratio. There were no significant differences in post-operative mechanical ventilation duration and incidence of grade 3 primary graft dysfunction between the two groups. At 1, 3, and 5 years, the percentage of predicted forced expiratory volume in 1 s (p = 0.767) and survival rate did not differ between groups (p = 0.924). The use of lungs from donors over 65 years for cystic fibrosis recipients allows extension of the donor pool without compromising results. Longer follow-up is needed to assess the long-term effects of this practice.

Conversion to belatacept after lung transplantation: Report of 10 cases.

BACKGROUND: Calcineurin inhibitors (CNIs) remain the cornerstone of maintenance immunosuppression (IS) after lung transplantation (LTx), although CNI-related life-threatening toxic effects may occur. Belatacept, a novel immunosuppressant that blocks a T-cell co-stimulation pathway, is a non-nephrotoxic drug indicated as an alternative to CNIs in kidney Tx. In LTx, there are only a few reports of belatacept conversion as a CNI-free or CNI-sparing IS treatment. METHODS: We reviewed a series of 10 LTx recipients with conversion to a CNI-free belatacept IS regimen within the first year post-LTx (n = 7) or a belatacept/low-dose CNI combination after the first year (n = 3). RESULTS: Use of belatacept was triggered by severe renal failure in 9 patients and under-IS with previous other IS-related toxicities in 1 patient. Mean estimated glomerular filtration rate after starting belatacept significantly improved at 6 months after initiation and at the last-follow-up (p = 0.006, and p = 0.002 respectively). The incidence of recurrent and/or severe acute cellular rejection (ACR) episodes was high in patients with CNI-free belatacept-based IS (n = 4/7). Chronic graft allograft dysfunction developed in 2 of 9 recipients under belatacept IS. Belatacept was stopped in 6 patients because of recurrent/severe ACR (n = 3), recurrent opportunistic infections (n = 1), center modified policy (n = 1), or other cause (n = 1). CONCLUSION: Early conversion to CNI-free belatacept-based IS improved renal function in this series but was counterbalanced by a high incidence of recurrent ACR, including life-threatening episodes. Other studies are needed to better determine the indications for its use after LTx, possibly with lower immunological risk IS regimens, such as CNI-sparing belatacept.

First use of imlifidase desensitization in a highly sensitized lung transplant candidate: a case report.

Lung transplant candidates who are highly sensitized against human leucocyte antigen present an ongoing challenge with regards to finding immunologically acceptable donors. Desensitization strategies aimed at reducing preformed donor-specific antibodies have a number of limitations. Imlifidase, an IgG-degrading enzyme derived from Streptococcus pyogenes, is a novel agent that has been used to convert positive crossmatches to negative in kidney transplant candidates, allowing transplantation to occur. We present the first case of imlifidase use for antibody depletion in a highly sensitized lung transplant candidate who went on to undergo a successful bilateral lung transplant.

Trans-arterial embolization for hemoptysis in lung transplant recipients.

INTRODUCTION: Hemoptysis isn't rare in lung transplant recipients (LTR). Yet, trans-arterial embolization (TAE) in LTR has been rarely reported in the literature. The aim of the study was to present the feasibility and outcomes of TAE for hemoptysis in LTR. MATERIALS AND METHODS: Retrospective study of all LTR who underwent TAE for hemoptysis in our single institution between 2005 and 2020. RESULTS: A total of 787 patients underwent lung transplantation between 2005 and 2020. Fifteen LTR underwent 21 TAE for hemoptysis in a median delay of 42 days after LT. TAE was performed within a year after LT in 13 patients (86.7%) with 12 of those patients having concomitant severe ischemic airway injury with necrosis and anastomotic dehiscence. Bronchoscopy confirmed bronchial anastomoses has being the source of the bleeding in 11 LTR (84.6%). Restoration of bronchial vascularization was highlighted in 13 patients (87%). Despite TAE, bronchial anastomosis healing was observed in all surviving patients with anastomotic dehiscence in a median delay of 43 days. CONCLUSION: In our experience, hemoptysis requiring TAE in LTR was rare, frequently occurring in the first weeks after LT, and seemed associated with anastomotic ischemia and dehiscence. Bleeding mainly originated from ischemic bronchial anastomosis through the restoration of the bronchial artery circulation. Our results suggest that bronchial arteriography should be routinely proposed in such patients in the event of hemoptysis.

Blood Lactate During Double-Lung Transplantation: A Predictor of Grade-3 Primary Graft Dysfunction.

OBJECTIVE: Many prognostic factors of grade-3 primary graft dysfunction at postoperative day 3 (PGD3-T72) have been reported, but intraoperative blood lactate level has not been studied. The present retrospective study was done to test the hypothesis that intraoperative blood lactate level (BLL) could be a predictor of PGD3-T72 after double-lung transplantation. DESIGN: Retrospective monocentric cohort study. SETTING: Foch University Hospital, Suresnes, France. PARTICIPANTS: Patients having received a double-lung transplantation between 2012 and 2019. Patients transplanted twice during the study period, having undergone a multiorgan transplantation, or cardiopulmonary bypass, and those under preoperative extracorporeal membrane oxygenation, were excluded. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Analysis was performed on a cohort of 449 patients. Seventy-two (16%) patients had a PGD3-T72. Blood lactate level increased throughout surgery to reach a median value of 2.2 (1.6-3.2) mmol/L in the No-PGD3-T72 group and 3.4 (2.3-5.0) mmol/L in the PGD3-T72 group after second lung implantation. The best predictive model for PGD3-T72 was obtained adding a lactate threshold of 2.6 mmol/L at the end of surgery to the clinical model, and the area under the curve was 0.867, with a sensitivity = 76.9% and specificity = 85.4%. Repeated-measures mixed model of BLL during surgery remained significant after adjustment for covariates (F ratio= 4.22, p < 0.001 for interaction). CONCLUSIONS: Blood lactate level increases during surgery and reaches a maximum after the second lung implantation. A value below the threshold of 2.6 mmol/L at the end of surgery has a high negative predictive value for the occurrence of a grade-3 primary graft dysfunction at postoperative day 3.

High-Emergency Lung Transplantation for Interstitial Lung Disease Associated With Anti-MDA5 Dermatomyositis: A Case Report.

BACKGROUND: Rapidly progressive interstitial lung disease (RPILD) associated with the anti-melanoma differentiation-associated gene 5 antibody-positive (anti-MDA5ab+) dermatomyositis (DM) is a rare but life-threatening condition despite immunosuppressive treatment. We report the case of a 44-year-old woman who was diagnosed with severe RPILD associated with anti-MDA5ab+ DM 1 week before her admission in the intensive care unit. The patient underwent a successful double-lung transplant after she failed treatment with immunosuppressive therapy, including tofacitinib. At 1-year follow-up, she had experienced no relapse of the disease. CASE REPORT: This case includes a patient recently diagnosed with RPILD for whom no treatment showed efficacy, including glucocorticoids, cyclophosphamide, plasma exchanges, tofacitinib, and tacrolimus. She was placed under mechanical ventilation and venovenous extracorporeal membrane oxygenation 2 weeks after diagnosis in a bridge-to-transplant process. She was successfully transplanted 20 days later after having been registered on the French National Lung Transplant Waiting List with high priority. One year after surgery, her pulmonary function tests were good, and she showed no sign of relapse of anti-MDA5ab+ DM. CONCLUSIONS: Lung transplantation can be a life-saving procedure in RPILD related to anti-MDA5ab+ DM. High-emergency allocation priority on the transplant list reduced the time between diagnosis and surgery. Patients without comorbidities should be promptly referred to specialized centers to rapidly assess the feasibility of transplantation in this context.

An Immunogenicity Report for the Comparison between Heterologous and Homologous Prime-Boost Schedules with ChAdOx1-S and BNT162b2 Vaccines.

BACKGROUND: There is a small amount of immunological data on COVID-19 heterologous vaccination schedules in humans. We assessed the immunogenicity of BNT162b2 (Pfizer/BioNTech) administered as a second dose in healthcare workers primed with ChAdOx1-S (Vaxzevria, AstraZeneca). METHODS: 197 healthcare workers were included in a monocentric observational study in Foch hospital, France, between June and July 2021. The main outcome was the immunogenicity measured by serum SARS-CoV-2 IgG antibodies. RESULTS: 130 participants received the ChAdOx1-S/BNT vaccine and 67 received the BNT/BNT vaccine. The geometric mean of IgG antibodies was significantly higher in the BNT/BNT vaccine group compared to the ChAdOx1-S/BNT vaccine group, namely 10,734.9, 95% CI (9141.1-12,589.3) vs. 7268.6, 95% CI (6501.3-8128.3), respectively (p < 0.001). However, after adjustment for time duration between the prime and second vaccinations, no significant difference was observed (p = 0.181). A negative correlation between antibody levels and time duration between second dose and serology test was observed for the BNT/BNT vaccine (p < 0.001), which remained significant after adjustment for all covariates (p < 0.001), but not for the ChAdOx1-S/BNT vaccine (p = 0.467). CONCLUSIONS: Heterologous and homologous schedules of ChAdOx1-S and BNT vaccines present robust immune responses after the second vaccination. The results observed were equivalent after adjustment for covariates and emphasize the importance of flexibility in deploying mRNA and viral vectored vaccines. Nevertheless, applying the ChAdOx1-S schedule vaccination for the heterologous second dose of BNT was associated with decreased IgG antibody levels compared to the homologous BNT/BNT vaccination.

COVID-19 in Lung Transplant Recipients: 2 Cases With Acute Respiratory Distress Syndrome Successfully Treated With High-Dose Corticosteroids.

Acute respiratory distress syndrome remains the main cause of death among people with COVID-19. Although many immunomodulatory and antiviral drug therapies have been tested, the only effective therapy against severe COVID-19 pneumonia among the general population is a regimen of high-dose corticosteroids for cases of severe associated inflammation. In solid-organ transplant recipients with long-term immunosuppression, data on disease presentation and evolution are scarce, and the benefit of high-dose corticosteroids remains uncertain for cases of severe COVID-19 pneumonia. Here, we report 2 cases of COVID-19-related acute respiratory distress syndrome that occurred in lung transplant recipients in March and April 2020, respectively. Both cases of acute respiratory distress syndrome occurred in patients with long-term azithromycin treatment prescribed to prevent chronic allograft dysfunction. Acute respiratory distress syndrome was associated with severe inflammation and was cured after early administration of high-dose corticosteroids in both cases, with progressive and complete resolution of lung lesions evidenced on thoracic computed tomography scan. Our findings support the benefit of early high-dose corticosteroids in COVID-19-related acute respiratory distress syndrome with hyperinflammation in patients with long-term immunosuppression such as lung transplant recipients.

A virtual crossmatch-based strategy for perioperative desensitisation in lung transplant recipients with pre-formed donor-specific antibodies: 3-year outcome.

BACKGROUND: Pre-formed donor-specific antibodies (DSAs) are associated with worse outcome after lung transplantation (LTx) and might limit access to LTx. A virtual crossmatch-based strategy for perioperative desensitisation protocol has been used for immunised LTx candidates since 2012 at Foch Hospital (Suresnes, France). We compared the outcome of desensitised LTx candidates with high DSA mean fluorescence intensity and those with low or no pre-formed DSAs, not desensitised. METHODS: For all consecutive LTx recipients (January 2012 to March 2018), freedom from chronic lung allograft dysfunction (CLAD) and graft survival were assessed using Kaplan-Meier analysis and Cox multivariate analysis. RESULTS: We compared outcomes for desensitised patients with high pre-formed DSAs (n=39) and those with no (n=216) or low pre-formed DSAs (n=66). The desensitisation protocol decreased the level of immunodominant DSA (class I/II) at 1, 3 and 6 months post-LTx (p<0.001, p<0.01 and p<0.001, respectively). Freedom from CLAD and graft survival at 3 years was similar in the desensitised group as a whole and other groups. Nevertheless, incidence of CLAD was higher with persistent high-level DSAs than cleared high-level (p=0.044) or no DSAs (p=0.014). Conversely, graft survival was better with cleared high DSAs than persistent high-level, low-level and no pre-formed DSAs (p=0.019, p=0.025 and p=0.044, respectively). On multivariate analysis, graft survival was associated with cleared high DSAs (hazard ratio 0.12, 95% CI 0.02-0.85 versus no DSAs; p=0.035) and CLAD with persistent DSAs (3.04, 1.02-9.17 versus no pre-formed DSAs; p=0.048). CONCLUSION: The desensitisation protocol in LTx recipients with high pre-formed DSAs was associated with satisfactory outcome, with cleared high pre-formed DSAs after desensitisation identified as an independent predictor of graft survival.

Operating room extubation: A predictive factor for 1-year survival after double-lung transplantation.

BACKGROUND: Operating room (OR) extubation has been reported after lung transplantation (LT) in small cohorts. This study aimed to evaluate the prognosis of OR-extubated patients. The secondary objectives were to evaluate the safety of this approach and to identify its predictive factors. METHODS: This retrospective single-center cohort study included patients undergoing double lung transplantation (DLT) from January 2012 to June 2019. Patients undergoing multiorgan transplantation, repeat transplantation, or cardiopulmonary bypass during the study period were excluded. OR-extubated patients were compared with intensive care unit (ICU)-extubated patients. RESULTS: Among the 450 patients included in the analysis, 161 (35.8%) were extubated in the OR, and 4 were reintubated within 24 hours. Predictive factors for OR extubation were chronic obstructive pulmonary disease (COPD)/emphysema (p = .002) and cystic fibrosis (p = .005), recipient body mass index (p = .048), and the PaO2/FiO2 ratio 10 minutes after second graft implantation (p < .001). OR-extubated patients had a lower prevalence of grade 3 primary graft dysfunction at day 3 (p < .001). Eight (5.0%) patients died within the first year after OR extubation, and 49 (13.5%) patients died after ICU extubation (log-rank test; p = .005). After adjustment for OR extubation predictive factors, the multivariate Cox regression model showed that OR extubation was associated with greater one-year survival (adjusted hazard ratio = 0.40 [0.16-0.91], p = .028). CONCLUSIONS: OR extubation was associated with a favorable prognosis after DLT, but the association should not be interpreted as causality. This fast-track protocol was made possible by a team committed to developing a comprehensive strategy to enhance recovery.

Intraoperative Implications of the Recipients' Disease for Double-Lung Transplantation.

OBJECTIVES: To compare intraoperative patterns among patients based on their primary pulmonary disease (cystic fibrosis [CF], chronic obstructive pulmonary disease [COPD]/emphysema [CE], and pulmonary fibrosis [PF]) during double- lung transplantation. The following 3 major outcomes were reported: blood transfusion, extracorporeal membrane oxygenation (ECMO) management, and the possibility of immediate extubation at the end of surgery. DESIGN: Retrospective analysis of a prospectively maintained database, including donor and recipient characteristics and intraoperative variables. SETTING: Foch Hospital, Suresnes, France (academic center performing 60-80 lung transplantations per year). PARTICIPANTS: Patients who underwent double- lung transplantation from 2012-2019. Patients with retransplantation, multiorgan transplantation, or surgery performed with cardiopulmonary bypass were excluded. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Two hundred forty-six patients had CF, 117 had CE, and 66 had PF. No patient had primary pulmonary arterial hypertension. Blood transfusion was higher in the CF group than in the other 2 groups (red blood cells [p < 0.001], fresh frozen plasma [p = 0.004]). The CF and CE groups were characterized by a lower intraoperative requirement of ECMO (p = 0.002), and the PF group more frequently required postoperative ECMO (p < 0.001). CF and CE patients were more frequently extubated in the operating room than were PF patients (37.4%, 50.4%, and 13.6%, respectively; p < 0.001). CONCLUSIONS: Intraoperative outcomes differed depending on the initial pathology. Such differences should be taken into account in specific clinical studies and in intraoperative management protocols.

Is Extracorporeal Membrane Oxygenation Withdrawal a Safe Option After Double-Lung Transplantation?

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) is commonly used during double-lung transplantation. ECMO can be planned or unplanned, and used only during the procedure or extended postoperatively (intraoperative or extended). Our practice is to limit its use and duration as much as possible. We conducted this retrospective single-center study to assess prognoses of patients undergoing unplanned-intraoperative ECMO. METHODS: From among 436 patients who underwent double-lung transplantation from 2012 to 2018, we excluded those who underwent bridge-to-transplantation, multiorgan transplantation, repeated transplantation during the study period, and cardiopulmonary bypass. Unplanned-intraoperative ECMO group was compared with no-ECMO and planned-intraoperative ECMO groups. RESULTS: In our sample, 209 patients did not require ECMO, 77 underwent unplanned-intraoperative ECMO, and 14 underwent planned-intraoperative ECMO. One-year and 3-year survival were lower in unplanned-intraoperative ECMO group than in the no-ECMO group (P = .043 and P = .032, respectively). The only independent protective factor related to 1-year mortality was history of cystic fibrosis (P = .013). Lung allocation score (P = .001), grade 3 pulmonary graft dysfunction at end-surgery status (P = .014), and estimated intraoperative blood loss (P = .031) were risk factors. CONCLUSIONS: Patients who underwent unplanned-intraoperative ECMO showed poorer prognoses than patients who did not require ECMO. This finding may be explained by differences in initial condition severity, by long-term consequences of the intraoperative complications leading to ECMO pump implantation, or by flaws in our weaning protocol.

Hanging donor lungs give good short-, mid- and long-term results in lung transplantation.

BACKGROUND: Hanging donors are considered as marginal donors and frequently unsuitable for lung transplantation. However, there is no evidence of higher lung transplantation (LTx) morbidity-mortality with lungs providing by hanging donor. METHODS: Between January 2010 and July 2015, we performed a retrospective study at Foch hospital. We aimed to assess whether hanging donor grafts are suitable for lung transplantation. RESULTS: A total of 299 LTx were performed. Subjects were allocated to a hanging group (HG) (n = 20) and a control group (CG) (n = 279). Donor and recipient characteristics did not differ. Primary graft dysfunction (PGD) at 72 hours was comparable in both groups (P = .75). The median duration of postoperative mechanical ventilation (1 [range, 0-84] vs 1 [range, 0-410] day, P = .35), the hospital length of stay (31 days [20-84] vs 32 days [12-435], P = .36) did not differ between the two groups. No statistically significant difference was found in 1-year and 5-year survival between the HG (83% and 78%) and the CG (86% and 75%), P = .85. CONCLUSION: We believe that hanging donors should be considered as conventional donors with particular caution in the final evaluation of the graft and in perioperative management.

Prognostic value of the PaO2 /FiO2 ratio determined at the end-surgery stage of a double-lung transplantation.

INTRODUCTION: We evaluated the prognostic role of the arterial oxygen partial pressure/fractional inspired oxygen ratio (PaO2 /FiO2 ratio) measured at the end of double-lung transplantation (DLT). METHODS: This was a monocentric cohort study of all consecutive DLT patients between January 1, 2012, and January 1, 2016, except patients with preoperative extracorporeal membrane oxygenation (ECMO), intraoperative cardiopulmonary bypass, postoperative ECMO, large patent foramen ovale, redo transplantation during the study period, and multiorgan transplantation. RESULTS: A total of 164 patients were included in the study; 45 had a PaO2 /FiO2 ratio <200, 39 a ratio in the range 200-300, and 80 a ratio >300. The risk of being in the lower ratio group is positively related to body mass index, preoperative pulmonary hypertension, and fibrosis. It is negatively related to emergency surgery, age, and intraoperative institution of ECMO. There was a trend for more grade 3 pulmonary graft dysfunction at day 3 in the worst PaO2 /FiO2 ratio group. Mortality at 1000 days was similar for all patients and even after exclusion of patients who had required intraoperative ECMO. CONCLUSION: PaO2 /FiO2 ratio measured at the end of DLT does not forecast 1000-day mortality.

Extracorporeal membrane oxygenation for grade 3 primary graft dysfunction after lung transplantation: Long-term outcomes.

INTRODUCTION: Extracorporeal membrane oxygenation (ECMO) is an efficient and innovative therapeutic tool for primary graft dysfunction (PGD). However, its effect on survival and long-term lung function is not well known. This study evaluated those parameters in patients with PGD requiring ECMO. METHOD: This single-center, retrospective study included patients who underwent LTx at our institute between January 2007 and December 2013. Patients and disease characteristics, survival, and pulmonary function tests were recorded. RESULTS: A total of 309 patients underwent LTx during the study period and 211 were included. The patients were predominantly male (53.5%), the median age was 39 years, and the primary pathology was suppurative disease (53.1%). ECMO for PGD was mandatory in 24 (11.7%) cases. Mortality at 3 months in the ECMO group was 50% (N = 12). However, long-term survival after PGD did not correlate with ECMO. Forced expiratory volume and vital capacity were significantly reduced in patients with PGD requiring ECMO, especially those with idiopathic pulmonary fibrosis. CONCLUSION: Veno-arterial ECMO appears to be suitable for management of PGD after LTx. Patients with PGD requiring ECMO show increased initial mortality; however, long-term survival was comparable with that of other patients in the study. Lung function does not appear to be related to PGD requiring ECMO.

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

BACKGROUND: Single transpulmonary thermodilution (SD) with extravascular lung water index (EVLWI) could become a new tool to better assess lung graft edema during ex-vivo lung perfusion (EVLP). In this study we compare EVLWI with conventional methods to better select lungs during EVLP and to predict post-transplant primary graft dysfunction (PGD). METHODS: We measured EVLWI, arterial oxygen/fraction of inspired oxygen (P/F) ratio, and static lung compliance (SLC) during EVLP in an observational study. At the end of EVLP, grafts were accepted or rejected according to a standardized protocol blinded to EVLWI results. We compared the respective ability of EVLWI, P/F, and SLC to predict PGD. Mann-Whitney U-test, Fisher's exact test, and receiver-operating characteristic (ROC) curve data were used for analysis. p < 0.05 was considered statistically significant. RESULTS: Thirty-five lungs were evaluated by SD during EVLP. Three lungs were rejected for pulmonary edema. Thirty-two patients were transplanted, 8 patients developed Grade 2 or 3 PGD, and 24 patients developed Grade 0 or 1 PGD. In contrast to P/F ratio, SLC, and pulmonary artery pressure, EVLWI differed between these 2 populations (p < 0.001). The area under the ROC for EVLWI assessing Grade 2 or 3 PGD at the end of EVLP was 0.93. Donor lungs with EVLWI >7.5 ml/kg were more likely associated with a higher incidence of Grade 2 or 3 PGD at Day 3. CONCLUSIONS: Increased EVLWI during EVLP was associated with PGD in recipients.

Inhaled nitric oxide dependency at the end of double-lung transplantation: a boosted propensity score cohort analysis.

Inhaled nitric oxide (iNO) is usually used during lung transplantation despite controversial postoperative benefits. Our group chose to administer iNO systematically during the procedure and stop at the end of surgery. This study aims to describe the features of patients who cannot be weaned from iNO, the reasons for this and its impact on postoperative outcomes. This is a monocentric cohort study comprised all consecutive patients who underwent double-lung transplantation (DLT) between 1 January 2012 and 1 January 2016. The impact of iNO dependency on postoperative outcomes was estimated using a boosted inverse probability of treatment weighting estimator. A total of 9.8% of the 173 patients included in the study could not be weaned from iNO at end-surgery stage. Body mass index (OR = 2.03, 95% CI = 1.14-3.29, P = 0.02) and intraoperative extracorporeal membrane oxygenation (OR = 1.80, 95% CI = 1.02-2.72, P = 0.04) were risk factors for iNO dependency In the weighted population, iNO dependency was associated with an increased prevalence of grade 3 primary graft dysfunction (adjusted RR = 4.20, 95% CI = 1.75-10.09, P < 0.001) and decreased postoperative survival during the first 1500 days of follow-up (adjusted HR = 5.0, 95% CI = 1.86-13.48, P < 0.001). Inhaled nitric oxide dependency is an early marker of a poor prognosis following DLT.