Abstract:OBJECTIVE Lung transplantation is an established treatment for end-stage pulmonary disease. Complications of lung transplantation include airway stenosis and dehiscence, reimplantation response, acute rejection, infection, posttransplantation lymphoproliferative disorder, and bronchiolitis obliterans syndrome. The incidence of graft rejection and airway anastomosis experienced in the early years of lung transplantation have been significantly reduced by advances in immunosuppression and surgical techniques. In… Show more
“…Several biomarkers have been proposed to improve the detection of lung transplant rejection, including 1 H magnetic resonance imaging (MRI) with ultra‐small superparamagnetic iron oxide (USPIO) particles, very short echo time (TE) 1 H MRI, technetium‐99 m‐based single photon emission computed tomography (SPECT), as well as blood‐based biomarkers like transplant tissue‐specific exosomal micro‐RNA and proteomic profiles . Yet none of these techniques are routinely used to detect lung rejection in the clinic, where radiography remains the predominant screening method …”
The current standard for noninvasive imaging of acute rejection consists of X-ray/CT, which derive their contrast from changes in ventilation, inflammation and edema, as well as remodeling during rejection. We propose the use of hyperpolarized [1-13 C] pyruvate MRI-which provides real-time metabolic assessment of tissue-as an early biomarker for tissue rejection.In this preliminary study, we used μCT-derived parameters and HP 13 C MR-derived biomarkers to predict rejection in an orthotopic left lung transplant model in both allogeneic and syngeneic rats.On day 3, the normalized lung density-a parameter that accounts for both lung volume (mL) and density (HU)-was −0.335 (CI: -0.598, −0.073) and − 0.473 (CI: -0.726, −0.220) for the allograft and isograft, respectively (not significant, 0.40). The lactate-to-pyruvate ratios-derived from the HP 13 C MRI-for the allograft and isograft were 0.200 (CI: 0.161, 0.240) and 0.114 (CI: 0.074, 0.153), respectively (significant, 0.020). Both techniques showed tissue rejection on day 7. A separate sub-study revealed CD8+ cells as the primary source of the lactate-to-pyruvate signal.Our study suggests that hyperpolarized (HP) [1-13 C] pyruvate MRI is a promising early biomarker for tissue rejection that provides metabolic assessment in real time based on changes in cellularity and metabolism of lung tissue and the infiltrating inflammatory cells, and may be able to predict tissue rejection earlier than X-ray/CT.
“…Several biomarkers have been proposed to improve the detection of lung transplant rejection, including 1 H magnetic resonance imaging (MRI) with ultra‐small superparamagnetic iron oxide (USPIO) particles, very short echo time (TE) 1 H MRI, technetium‐99 m‐based single photon emission computed tomography (SPECT), as well as blood‐based biomarkers like transplant tissue‐specific exosomal micro‐RNA and proteomic profiles . Yet none of these techniques are routinely used to detect lung rejection in the clinic, where radiography remains the predominant screening method …”
The current standard for noninvasive imaging of acute rejection consists of X-ray/CT, which derive their contrast from changes in ventilation, inflammation and edema, as well as remodeling during rejection. We propose the use of hyperpolarized [1-13 C] pyruvate MRI-which provides real-time metabolic assessment of tissue-as an early biomarker for tissue rejection.In this preliminary study, we used μCT-derived parameters and HP 13 C MR-derived biomarkers to predict rejection in an orthotopic left lung transplant model in both allogeneic and syngeneic rats.On day 3, the normalized lung density-a parameter that accounts for both lung volume (mL) and density (HU)-was −0.335 (CI: -0.598, −0.073) and − 0.473 (CI: -0.726, −0.220) for the allograft and isograft, respectively (not significant, 0.40). The lactate-to-pyruvate ratios-derived from the HP 13 C MRI-for the allograft and isograft were 0.200 (CI: 0.161, 0.240) and 0.114 (CI: 0.074, 0.153), respectively (significant, 0.020). Both techniques showed tissue rejection on day 7. A separate sub-study revealed CD8+ cells as the primary source of the lactate-to-pyruvate signal.Our study suggests that hyperpolarized (HP) [1-13 C] pyruvate MRI is a promising early biomarker for tissue rejection that provides metabolic assessment in real time based on changes in cellularity and metabolism of lung tissue and the infiltrating inflammatory cells, and may be able to predict tissue rejection earlier than X-ray/CT.
“…Improvement in surgical procedures, in particular bronchial anastomosis techniques and the endoscopic management of stenosis or leakage, has contributed to reduce airway complications [ 3 , 4 ]. Furthermore, systematic infection prophylaxis and a trend for virus serology matching have significantly reduced post-operative morbidity and improved long-term survival with reduced chronic allograft dysfunction [ 5 ].…”
Section: Introductionmentioning
confidence: 99%
“…Complications after lung transplantation vary depending on the delay of their occurrence. Figure 1 summarizes the mean time of occurrence and the greatest incidence of complications depending on the time after the procedure and according to the literature [ 4 , 6 , 7 ]. Fig.…”
Section: Introductionmentioning
confidence: 99%
“…1 Onset of complications following lung transplantation. Adapted from Ng et al 2009 [ 4 ]. CLAD: chronic lung allograft dysfunction; PGD: primary graft dysfunction; PTLD: post-transplantation lymphoproliferative disease; D: day; W: week; M: month; Y: year …”
Complications following lung transplantation may impede allograft function and threaten patient survival. The five main complications after lung transplantation are primary graft dysfunction, post-surgical complications, alloimmune responses, infections, and malignancy. Primary graft dysfunction, a transient ischemic/reperfusion injury, appears as a pulmonary edema in almost every patient during the first three days post-surgery. Post-surgical dysfunction could be depicted on computed tomography (CT), such as bronchial anastomosis dehiscence, bronchial stenosis and bronchomalacia, pulmonary artery stenosis, and size mismatch. Alloimmune responses represent acute rejection or chronic lung allograft dysfunction (CLAD). CLAD has three different forms (bronchiolitis obliterans syndrome, restrictive allograft syndrome, acute fibrinoid organizing pneumonia) that could be differentiated on CT. Infections are different depending on their time of occurrence. The first post-operative month is mostly associated with bacterial and fungal pathogens. From the second to sixth months, viral pneumonias and fungal and parasitic opportunistic infections are more frequent. Different patterns according to the type of infection exist on CT. Malignancy should be depicted and corresponded principally to post-transplantation lymphoproliferative disease (PTLD). In this review, we describe specific CT signs of these five main lung transplantation complications and their time of occurrence to improve diagnosis, follow-up, medical management, and to correlate these findings with pathology results.Key Points• The five main complications are primary graft dysfunction, surgical, alloimmune, infectious, and malignancy complications.• CT identifies anomalies in the setting of unspecific symptoms of lung transplantation complications.• Knowledge of the specific CT signs can allow a prompt diagnosis.• CT signs maximize the yield of bronchoscopy, transbronchial biopsy, and bronchoalveolar lavage.• Radiopathological correlation helps to understand CT signs after lung transplantation complications.
“…Other CT findings frequently seen in patients with BOS are bronchiectasis, mucus plugging, and consolidations [9], [10], [11]. However, it has been shown that none of these findings could predict the development of BOS [12].…”
ObjectivesTo prospectively evaluate quantitative airway wall measurements of thin-section CT for the diagnosis of Bronchiolitis Obliterans Syndrome (BOS) following lung transplantation.Materials and MethodsIn 141 CT examinations, bronchial wall thickness (WT), the wall area percentage (WA%) calculated as the ratio of the bronchial wall area and the total area (sum of bronchial wall area and bronchial lumen area) and the difference of the WT on inspiration and expiration (WTdiff) were automatically measured in different bronchial generations. The measurements were correlated with the lung function parameters. WT and WA% in CT examinations of patients with (n = 25) and without (n = 116) BOS, were compared using the unpaired t-test and univariate analysis of variance, while also considering the differing lung volumes.ResultsMeasurements could be performed in 2,978 bronchial generations. WT, WA%, and WTdiff did not correlate with the lung function parameters (r<0.5). The WA% on inspiration was significantly greater in patients with BOS than in patients without BOS, even when considering the dependency of the lung volume on the measurements. WT on inspiration and expiration and WA% on expiration did not show significant differences between the groups.ConclusionWA% on inspiration was significantly greater in patients with than in those without BOS. However, WA% measurements were significantly dependent on lung volume and showed a high variability, thus not allowing the sole use of bronchial wall measurements to differentiate patients with from those without BOS.
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