Abstract 777: Antitumor role of early infiltrating interferon-gamma producing NKT cells in murine malignant mesothelioma

Introduction: NKT cells can provide adjuvant activity against cancer by producing large amounts of IFN-gamma which activate other immune cells, and orchestrate protective anti-tumor immunity. Recently, induction of the NKT cell-dependent anti-tumor immune response using its ligand alpha-galactosylceramide has been attempted in several tumor types. However, the role of NKT cells in the tumor microenvironment has not yet been fully addressed. Our aim is to elucidate the role of NKT cells in the thoracic cavity by using a murine malignant mesothelioma model.

Methods: Half a million of AB12 murine malignant mesothelioma cells were injected into the right pleural cavity of female Balb/c mice for tumor development. The control mice were injected with the same amount of PBS. In this model, thoracic cavity was filled with tumors and pleural effusion by day 14. On days 0 (before tumor cell injection), 3, 6, 10 and 14 after tumor cell injection, mice were sacrificed and the pleural effusion and tumors were collected. Lymphocytes were isolated by performing a Ficoll gradient centrifugation. Cell phenotype was identified by cell surface marker staining and cytokine expression was analyzed by intracellular cytokine staining using flow cytometry. Cytokine concentrations in the pleural effusion were measured by ELISA.

Resluts: The absolute number of CD3 positive cells in the pleural cavity did not increase between day 0 (4.7±0.9 x105), day 3 (5.5±0.7 x105) and day 6 (7.1x±1.6 x105) but did start to increase from day 10 (1.2±0.2 x106) after tumor cell injection. In the control mice, the absolute number of CD3 positive cells was not different throughout the experiment. Although the absolute number of CD8 positive cells and CD4 positive cells were not different between day 0 (CD8: 1.5±0.2 x105, CD4: 2.8±0.2 x105, respectively), day 3 (CD8: 1.8±0.2 x105, CD4: 2.6±0.2 x105, respectively) and day 6 (CD8: 1.9±0.4 x105, CD4: 4.3±0.2 x105, respectively) after tumor cell injection, the absolute number of NKT cells (CD3 and DX5 double positive cells) increased dramatically at relatively earlier phase from 1.6±0.1 x104 on day 0, to 6.4±0.3 x104 on day 3 and 12.1±1.0 x104 on day 14. Intracellular IFN-gamma staining of NKT and CD8 T cells showed that the ratio of IFN-gamma positive NKT to whole NKT cells started increasing from day 3 (day0: 7.0±1.3%, day3: 31±3%, respectively) and peaked on day 6 (59±11%) whereas the ratio of IFN-gamma positive to whole CD8 T cells started increasing from day 6 (day0: 12.1±3.5%, day6: 36±6.5%) and peaked on day 10 (39±3.4%).

Conclusion: These results indicate that the NKT cells are recruited to the pleural cavity at a relatively early phase of tumor formation and could potentially affect the subsequent CD8 T cell response by the production of IFN-gamma. Further experiments are on going to see the role of NKT cells and to test the impact of chemotherapy on these cells in this model.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 777. doi:10.1158/1538-7445.AM2011-777

Normothermic ex vivo lung perfusion in clinical lung transplantation

BACKGROUND

More than 80% of donor lungs are potentially injured and therefore not considered suitable for transplantation. With the use of normothermic ex vivo lung perfusion (EVLP), the retrieved donor lung can be perfused in an ex vivo circuit, providing an opportunity to reassess its function before transplantation. In this study, we examined the feasibility of transplanting high-risk donor lungs that have undergone EVLP.

METHODS

In this prospective, nonrandomized clinical trial, we subjected lungs considered to be high risk for transplantation to 4 hours of EVLP. High-risk donor lungs were defined by specific criteria, including pulmonary edema and a ratio of the partial pressure of arterial oxygen to the fraction of inspired oxygen (PO(2):FIO(2)) less than 300 mm Hg. Lungs with acceptable function were subsequently transplanted. Lungs that were transplanted without EVLP during the same period were used as controls. The primary end point was primary graft dysfunction 72 hours after transplantation. Secondary end points were 30-day mortality, bronchial complications, duration of mechanical ventilation, and length of stay in the intensive care unit and hospital.

RESULTS

During the study period, 136 lungs were transplanted. Lungs from 23 donors met the inclusion criteria for EVLP; in 20 of these lungs, physiological function remained stable during EVLP and the median PO(2):FIO(2) ratio increased from 335 mm Hg in the donor lung to 414 and 443 mm Hg at 1 hour and 4 hours of perfusion, respectively (P<0.001). These 20 lungs were transplanted; the other 116 lungs constituted the control group. The incidence of primary graft dysfunction 72 hours after transplantation was 15% in the EVLP group and 30% in the control group (P=0.11). No significant differences were observed for any secondary end points, and no severe adverse events were directly attributable to EVLP.

CONCLUSIONS

Transplantation of high-risk donor lungs that were physiologically stable during 4 hours of ex vivo perfusion led to results similar to those obtained with conventionally selected lungs. (Funded by Vitrolife; ClinicalTrials.gov number, NCT01190059.).

Increased levels of interleukin-1β and tumor necrosis factor-α in donor lungs rejected for transplantation

BACKGROUND

Cytokine analysis of the donor lung shows significant promise as a strategy to biologically evaluate the organ before transplantation. This study compared gene expression levels of inflammatory cytokines between clinically rejected and transplanted donor lungs.

METHODS

Lung tissue biopsy specimens were taken from 17 clinically unsuitable lungs and 24 transplanted donor lungs before cold flush perfusion preservation. Expression levels of interleukin (IL)-6, IL-8, IL-10, interferon-γ, tumor necrosis factor (TNF)-α, and IL-1β messenger (m)RNA were measured in a blinded fashion by quantitative real-time reverse transcription polymerase chain reaction. Prospectively collected clinical data were analyzed retrospectively and compared with cytokine expression results. The primary end point was to examine the difference of expression levels of these cytokines between rejected donor lungs and lungs used for transplantation.

RESULTS

The ratio of partial pressure of oxygen/fraction of inspired oxygen, time on ventilation, infiltrates on chest X-ray images, and abnormal bronchoscopic findings for donors were statistically different between rejected and transplanted donor lungs. Comparison of gene expression levels showed that clinically rejected lungs had significantly higher levels of IL-1β and TNF-α than the lungs used for transplantation. Hierarchic clustering with IL-1β and TNF-α showed that 4 clinically unsuitable donor lungs had very low levels of these 2 cytokines.

CONCLUSION

Levels of IL-1β and TNF-α are significantly higher in donor lungs rejected for transplantation using clinical criteria. However, a sub-set of non-used lungs had low levels of IL-1β and TNF-α and thus could potentially have been used for transplantation. In the near future, these markers could be used to assist in the lung donor selection process and to monitor organ reparative strategies.

Functional repair of human donor lungs by IL-10 gene therapy

More than 80% of potential donor lungs are injured during brain death of the donor and from complications experienced in the intensive care unit, and therefore cannot be used for transplantation. These lungs show inflammation and disruption of the alveolar-capillary barrier, leading to poor gas exchange. Although the number of patients in need of lung transplantation is increasing, the number of donors is static. We investigated the potential to use gene therapy with an adenoviral vector encoding human interleukin-10 (AdhIL-10) to repair injured donor lungs ex vivo before transplantation. IL-10 is an anti-inflammatory cytokine that mainly exerts its suppressive functions by the inactivation of antigen-presenting cells with consequent inhibition of proinflammatory cytokine secretion. In pigs, AdhIL-10-treated lungs exhibited attenuated inflammation and improved function after transplantation. Lungs from 10 human multiorgan donors that had suffered brain death were determined to be clinically unsuitable for transplantation. They were then maintained for 12 hours at body temperature in an ex vivo lung perfusion system with or without intra-airway delivery of AdhIL-10 gene therapy. AdhIL-10-treated lungs showed significant improvement in function (arterial oxygen pressure and pulmonary vascular resistance) when compared to controls, a favorable shift from proinflammatory to anti-inflammatory cytokine expression, and recovery of alveolar-blood barrier integrity. Thus, treatment of injured human donor lungs with the cytokine IL-10 can improve lung function, potentially rendering injured lungs suitable for transplantation into patients.

Soluble mesothelin-related Peptide and osteopontin as markers of response in malignant mesothelioma

PURPOSE

In malignant mesothelioma (MM), radiologic assessment of disease status is difficult. Both soluble mesothelin-related peptide (SMRP) and osteopontin (OP) have utility in distinguishing MM from benign pleural disease. We evaluated whether SMRP and OP also correlated with the disease course of MM.

PATIENTS AND METHODS

Serial plasma samples from patients with MM were prospectively collected, and SMRP and OP levels were measured. Radiologic tests across time periods showing disease progression, stability, or shrinkage were compared with corresponding changes in SMRP/OP levels.

RESULTS

From 41 patients, 165 samples were collected (range, 2 to 10; median 4). At study entry, 37 of 41 patients had measurable disease, of whom 92% (34 of 37) had elevated baseline SMRP levels; four of 41 patients had no evidence of recurrence and each had normal baseline SMRP levels. In 21 patients receiving systemic therapy, percentage change in SMRP more than 10% correlated with the radiologic assessment by a trained thoracic radiologist (P < .001), by formal Response Evaluation Criteria in Solid Tumors (RECIST; P = .008), or by modified RECIST (P < .001). All seven patients who underwent surgical resection with negative margins had elevated preoperative SMRP levels that fell to normal postoperatively. Rising SMRP was observed in all patients with radiologic disease progression. No associations were found with OP.

CONCLUSION

Percentage changes in SMRP levels, but not changes in OP levels, are a potentially useful marker of disease course. These findings should be validated prospectively for a role as an objective adjunctive measure of disease course in both clinical trials and clinical practice.

Technique for prolonged normothermic ex vivo lung perfusion

BACKGROUND

The inhibition of cellular metabolism induced by hypothermia obviates the possibility of substantial reparative processes occurring during organ preservation. The aim of this study was to develop a technique of extended (12-hour) ex vivo lung perfusion (EVLP) at normothermia for assessment and protective maintenance of the donor lung.

METHODS

Six double-lung blocks from 35-kg pigs and 5 single human lungs were subjected to 12 hours of normothermic EVLP using acellular Steen Solution. In the animal studies, the left lung was transplanted into recipients at the end of EVLP and reperfused for 4 hours to evaluate the impact of prolonged EVLP on post-transplant lung function. A protective mode of mechanical ventilation with controlled perfusion flows and pressures in the pulmonary vasculature were employed during EVLP. Lung oxygenation capacity (DeltaPo(2)), pulmonary vascular resistance and airway pressures were evaluated in the system. Red blood cells were added to the perfusate to a hematocrit of 20% at the end of human lung EVLP to study lung functional assessment with and without cells.

RESULTS

Lung function was stable during 12 hours of EVLP. This stability during prolonged normothermic EVLP translated into excellent post-transplant lung function (Pao(2)/Fio(2): 527 +/- 22 mm Hg), low edema formation (wet/dry ratio: 5.24 +/- 0.38) and preserved lung histology after transplantation. The acellular perfusion assessment of lung function accurately correlated with post-transplant graft function.

CONCLUSIONS

Twelve hours of EVLP at physiologic temperatures using an acellular perfusate is achievable and maintains the donor lungs without inflicting significant added injury. This system can be used to assess, maintain and treat injured donor lungs.

Trimodality therapy with induction chemotherapy followed by extrapleural pneumonectomy and adjuvant high-dose hemithoracic radiation for malignant pleural mesothelioma

PURPOSE

Malignant pleural mesothelioma (MPM) remains associated with poor outcome. We examined the results of trimodality therapy with cisplatin-based chemotherapy followed by extrapleural pneumonectomy (EPP) and adjuvant high-dose (50 to 60 Gy) hemithoracic radiation therapy for MPM.

PATIENTS AND METHODS

We conducted a retrospective review of all patients prospectively evaluated for trimodality therapy protocol between January 2001 and December 2007 in our institution.

RESULTS

A total of 60 patients were suitable candidates. Histology was epithelioid (n = 44) or biphasic (n = 16). Chemotherapy regimens included cisplatin/vinorelbine (n = 26), cisplatin/pemetrexed (n = 24), cisplatin/raltitrexed (n = 6), or cisplatin/gemcitabine (n = 4). EPP was performed in 45 patients, and hemithoracic radiation therapy to at least 50 Gy was administered postoperatively to 30 patients. Completion of the trimodality therapy in the absence of mediastinal node involvement was associated with the best survival (median survival of 59 months v <or= 14 months in the remaining patients, P = .0003). The type of induction chemotherapy had no significant impact on survival. Pathologic nodal status remained a significant predictor of poor survival despite completion of the trimodality therapy. After completion of the protocol, the 5-year disease-free survival was 53% for patients with N0 disease, reaching 75% in patients with ypT1-2N0 and 45% in patients with ypT3-4N0.

CONCLUSION

This large, single-center experience with induction chemotherapy followed by EPP and adjuvant high-dose hemithoracic radiation for MPM shows that half of the patients are able to complete this protocol. The results are encouraging for patients with N0 disease. However, N2 disease remains a major factor impacting on survival, despite completion of the entire trimodality regimen.

Regression of flow-induced pulmonary arterial vasculopathy after flow correction in piglets

OBJECTIVES

Chronic thromboembolic pulmonary hypertension is due to partial obstruction of the pulmonary arterial bed and may resolve after pulmonary thromboendarterectomy. Persistent pulmonary hypertension, the main complication after pulmonary thromboendarterectomy, may reflect vessel alterations induced by high flow in unobstructed lung territories. The aim of this study was to determine whether correcting high flow led to reversal of the vasculopathy in piglets.

METHODS

The effects of high pulmonary blood flow were investigated 5 weeks after creation of an aortopulmonary shunt (n = 10), and reversibility of vessel disease was evaluated at 1 week (n = 10) and 5 weeks after shunt closure (n = 10), compared to sham-operated animals (n = 10). Hemodynamic variables, pulmonary artery reactivity, and morphometry were recorded. We also investigated the endothelin, angiopoietin, and nitric oxide synthase pathways.

RESULTS

High flow increased medial thickness in distal pulmonary arteries (55.6% +/- 1.2% vs 35.9% +/- 0.8%; P < .0001) owing to an increase of smooth muscle cell proliferation (proliferating cell nuclear antigen labeling). The endothelium-dependent relaxation was altered (P < .05). This phenomenon was associated to an overexpression of endothelin-1, endothelin-A, angiopoietin 1, angiopoietin 2, and Tie-2 (P < .05). After 1 week of shunt closure, all overexpressed genes returned to control values, the proliferation of smooth muscle cells stopped, and smooth muscle cell apoptosis increased (terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling), preceding the normalization of the wall thickness hypertrophy and the pulmonary artery vasoreactivity observed at 5 weeks after shunt closure.

CONCLUSION

These results demonstrate that endothelin-1 and angiopoietin pathways are involved in vasculopathy development and may be important therapeutic targets for preventing persistent pulmonary hypertension after pulmonary thromboendarterectomy.

Evaluation of Persistent Pulmonary Hypertension After Acute Pulmonary Embolism

BACKGROUND

Better knowledge of the evolution of persistent pulmonary hypertension after acute pulmonary embolism (PE) is required to optimize the indication and timing of pulmonary endarterectomy (PEA).

METHODS

We reviewed our experience with 17 consecutive patients demonstrated to have persistent pulmonary hypertension after acute massive (n = 1), submassive (n = 7), or recurrent PE (n = 9).

RESULTS

After a median of 18 weeks of anticoagulation (range, 12 to 30 weeks) since the last PE, 10 patients showed residual pulmonary artery systolic pressure (PAsP) > 50 mm Hg. These patients demonstrated a significant progression in PAsP over the ensuing 6 to 12 months, from 73 +/- 14 to 101 +/- 26 mm Hg (p = 0.005) [mean +/- SD], and eight patients were found to be suitable candidates for PEA. In contrast, among seven patients with residual PAsP from 35 to 40 mm Hg (n = 3) and 41 to 50 mm Hg (n = 4), six patients had evidence of residual perfusion defects on the ventilation/perfusion scan and CT. The PAsP did not change significantly over the ensuing 6 to 12 months, except in two patients who had new episodes of acute PE.

CONCLUSIONS

Two groups of patients can be identified based on the degree of residual pulmonary hypertension after acute PE. Patients with residual PAsP > 50 mm Hg should be evaluated for PEA since their pulmonary artery pressures will significantly progress over the ensuing 6 to 12 months despite the absence of recurrent PE. In contrast, patients with PAsP from 35 to 50 mm Hg are at risk for severe pulmonary hypertension if new PE occurs, and should therefore be closely monitored.

Extracorporeal membrane oxygenation for primary graft dysfunction after lung transplantation: analysis of the Extracorporeal Life Support Organization (ELSO) registry

BACKGROUND

Some patients with severe primary graft dysfunction (PGD) after lung transplantation (LTx) require gas exchange support using an extracorporeal membrane oxygenator (ECMO) as a life-saving therapy. A few single-center experiences have been reported with relatively few cases of ECMO after LTx.

METHODS

We reviewed outcomes of ECMO in lung transplant recipients included in the Extracorporeal Life Support Organization (ELSO) registry, which was established with the intention to improve quality and outcome of extracorporeal life support (ECLS) in patients treated with ECMO applied for all indications.

RESULTS

The ELSO registry currently includes 31,340 ECMO cases, of which 151 were post-LTx patients with primary graft dysfunction (PGD). The mean age was 35 +/- 18 years. Indications for LTx were acute respiratory distress syndrome, (15%), cystic fibrosis (15%), idiopathic pulmonary fibrosis (8%), primary pulmonary hypertension, (10%), emphysema (15%), acute lung failure (11%), other (23%), and unknown (3%). ECMO run time was 140 +/- 212 hours. Venovenous ECMO was used in 25, venoarterial in 89, and other modes in 15 patients (unknown in 22). ECMO was discontinued in 93 patients owing to lung recovery. It was also discontinued in 29 patients with multiorgan failure, in 22 patients that died with no further specification, and in 7 patients for other reasons. In total, 63 (42%) patients survived the hospital stay. Major complications during ECMO included hemorrhage (52%), hemodialysis (42%), neurologic (12%), and cardiac (28%) complications, inotropic support (77%), and sepsis (15%).

CONCLUSIONS

Although the ELSO registry was not primarily established to study ECMO in LTx, it provides valuable insights and evidence that there is indeed an appreciable salvage rate with the use of ECMO for PGD after LTx. Clearly, this is a very high-risk patient population, and no single center can accumulate a large experience of ECMO for this specific indication. These data, however, underscore the importance of developing a specific registry for patients put on ECLS devices so that we can better study the outcomes, determine optimum treatment strategies, and optimize patient and device selection, and thus improve the outcomes of patients requiring this unique therapy.

Role of surgery in the treatment of primary pulmonary B-cell lymphoma

BACKGROUND

The purpose of this study was to define the role of surgery in the treatment of primary pulmonary lymphoma (PPL).

METHODS

We reviewed all patients presenting with a pathologic diagnosis of PPL in our institution during the past 20 years. We analyzed the outcome and determined the impact of complete versus incomplete surgical resection on survival.

RESULTS

The study included 17 patients with PPL confined to the pulmonary parenchyma. Pathologic diagnosis was low-grade B-cell PPL in 14 patients, high-grade B-cell PPL in 2, and lymphomatoid granulomatosis in 1. A complete resection was performed in 8 patients presenting with low-grade B-cell PPL and in 2 patients with high-grade B-cell PPL. The overall survival of patients presenting with low-grade B-cell PPL was 63% at 10 years; however, survival at 10 year tended to be better when a complete resection was performed (87.5% vs 25%, respectively; p = 0.08). Gender, bilateral disease, or adjuvant therapy did not affect survival. Both patients presenting with high-grade B-cell PPL are alive and free of disease 22 and 36 months after the surgery, respectively. The patient presenting with lymphomatoid granulomatosis is alive after 2 years of follow-up.

CONCLUSIONS

PPL is a rare disease that may be localized or diffuse in one or both lungs. Surgery should be the treatment of choice in the localized form of PPL if complete resection can be achieved. A complete resection is associated with an excellent long-term survival of almost 90%. If the lesions are diffuse or involve both lungs, medical therapy should then be the treatment of choice.

Impact of lymph node metastasis on outcome after extrapleural pneumonectomy for malignant pleural mesothelioma

OBJECTIVES

Extrapleural pneumonectomy is a therapeutic option for selected patients with malignant pleural mesothelioma. The impact of lymph node metastasis on the site of recurrence and the role of mediastinoscopy in the selection of patients for extrapleural pneumonectomy, however, remain unclear.

METHODS

We reviewed 50 consecutive patients undergoing extrapleural pneumonectomy for malignant pleural mesothelioma in our institution between January 1993 and March 2005.

RESULTS

The median survival was 11 months, with a 3-year survival of 24%. Survival was significantly worse for patients with N2 disease than for those with no lymph node metastasis (median survival 10 months vs 29 months, respectively, P = .005). Patient sex, histologic cell type, stage, and N2 disease, but not mediastinoscopy, had significant impacts on survival according to univariate analysis. In a multivariate analysis, however, only the presence of N2 disease remained a significant predictor of poor outcome. The proportion of patients with N2 disease and the long-term survival was similar regardless of whether preoperative mediastinoscopy yielded a negative result. The initial site of recurrence was determined in 28 patients (locoregional in 10 and distant in 18). The presence of N2 disease had no impact on the site of recurrence. Adjuvant hemithoracic radiation therapy, however, significantly decreased the risk of locoregional recurrence.

CONCLUSIONS

The presence of N2 disease negatively affects the prognosis of patients with malignant pleural mesothelioma. Mediastinoscopy, however, seems to have a limited role in patient selection for extrapleural pneumonectomy. Adjuvant hemithoracic radiation therapy but not N2 disease affects the risk of locoregional recurrence.

Prevalence of gastroesophageal reflux in end-stage lung disease candidates for lung transplant

BACKGROUND

Aspiration secondary to gastroesophageal reflux has been postulated to be a contributing factor in bronchiolitis obliterans after lung transplantation. It is not clear whether gastroesophageal reflux is a preexisting condition or secondary to intraoperative vagal injury or drug-induced prolonged gastric emptying.

METHODS

The prevalence of gastroesophageal reflux was examined in 78 consecutive end-stage lung disease patients assessed for lung transplantation: emphysema, 21; cystic fibrosis, 5; idiopathic pulmonary fibrosis, 26; scleroderma, 10; and miscellaneous diseases, 16. All underwent esophageal manometry. Two-channel esophageal 24-hour pH testing was completed in 76 patients. Gastric emptying studies were conducted in 36 patients.

RESULTS

Typical gastroesophageal reflux symptoms were documented in 63% of patients. The lower esophageal sphincter was hypotensive in 72% of patients, and 33% had esophageal body dysmotility. Prolonged gastric emptying was documented in 44%, and 38% had abnormal pH testing. The overall DeMeester score was above normal in 32% of patients, and 20% had abnormal proximal pH probe readings.

CONCLUSIONS

Gastroesophageal reflux is highly prevalent in end-stage lung disease patients who are candidates for lung transplantation. Further investigation is needed to study the prevalence of gastroesophageal reflux after lung transplantation and its contribution to chronic allograft dysfunction.

Independent ventilation of the graft and native lungs in vivo after rat lung transplantation

Rat lung transplantation is a proven experimental technique for the study of lung injury following lung transplantation. We have modified the surgical and ventilatory techniques to allow for independent ventilation in vivo of the transplanted graft and native lungs. This will provide additional data on the physiology and function of the transplanted graft and ameliorate the problem of progressive graft lung collapse and thereby allow for an improved model of ischemia-reperfusion injury and ventilator-induced lung injury in the setting of lung transplantation.