Evolución clínica, funcional y radiológica de pacientes trasplantados pulmonares con síndrome de bronquiolitis obliterante y disfunción de injerto pulmonar restrictivo / Clinical, functional and radiological evolution of pulmonary transplant patients with bronchiolitis obliterans syndrome and restrictive graft dysfunction

Resumen La principal complicación a largo plazo en trasplantados de pulmón es la disfunción crónica de injerto identificado como bronquiolitis obliterante, existiendo un nuevo patrón denominado Disfunción de Injerto Restrictivo. Objetivo: Evaluar seguimiento espirométrico, radiológico y clínico entre pacientes con síndrome de bronquiolitis obliterante (SBO) y Disfunción de Injerto Restrictivo (DIR) post trasplante pulmonar. Metodología: Se revisaron registros clínicos de trasplantados pulmonares desde 1999 hasta 2017. Se efectuó seguimiento espirométrico e imágenes por tomografía de tórax y factores asociados: infección por Citomegalovirus(CMV), reflujo gastro-esofágico (RGE) y episodios de rechazo agudo. Se analizó sobrevida por Kaplan Meier. Resultados: De 88 pacientes trasplantados de pulmón, 40 desarrollaron disfunción crónica de injerto: 31 (80%) presentaron SBO y 9 (20%) tuvieron DIR. Edad promedio: 47 años en SBO y 46 años en DIR. Siendo fibrosis pulmonar la patología basal predominante en ambos. En SBO se consignaron 14 episodios de rechazo agudo (50%), infección por CMV en 18% y RGE activo en 26%. En la serie DIR hubo 5 episodios de rechazo agudo (62%), 13% de infección por CMV y 67% de RGE activo 6 (p = 0,02). En el seguimiento a 1-2-4-5 años el promedio del VEF1 en SBO fue: 67,3,65, 60 y 48% del valor predicho y en DIR fue 61, 65, 62 y 45% respectivamente. Las imágenes tomográficas en SBO mostraron: hiperinflación y en DIR: fibrosis pleuropulmonar superior. La sobrevida fue de 96,9 meses en SBO y 65,6 meses en DIR (p = 0,06). Conclusions: La disfunción restrictiva presentó menor sobrevida que SBO. RGE se asoció a rechazo restrictivo. La tomografía de tórax difiere en ambos tipos de rechazo crónico.

The main long-term complication in lung transplant patients is chronic graft dysfunction identified as bronchiolitis obliterans, and there is a new pattern called Restrictive Graft Dysfunction. Objective: To evaluate spirometric, radiological and clinical follow-up among patients with bronchiolitis obliterans syndrome (BOS) and Restrictive Allograft Syndrome (RAS) after lung transplantation. Methodology: Lung transplant recipients ' clinical records were reviewed from 1999 to 2017. We carried out a follow up of spirometry, chest tomography imaging and associated factors: cytomegalovirus (CMV) infection, gastroesophageal reflux (GER) and episodes of acute rejection. Survival was analyzed by Kaplan Meier. Results: Out of 88 lung transplant patients, 40 developed chronic graft dysfunction: 31 (80%) presented BOS and 9 (20%) had RAS. Mean age: 47 yr.o. in BOS and 46 yr. o. in RAS. Lung fibrosis was the primary pathology predominant in both conditions. In BOS were reported 14 episodes of acute rejection (50%), CMV infection in 18% and active GER in 26%. In RAS there were 5 episodes of acute rejection (62%), CMV infection in 13% and active GER in 67% (p = 0.02). VEF1 follow-up at 1-2-4-5 years averaged 67, 65, 60 and 8% of reference value in BOS and 61, 65, 62 and 45% in RAS respectively. CT scans showed hyperinflation in BOS and upper pleuropulmonary fibrosis in RAS. BOS survival time was 96.9 months versus 65.6 months in RAS (p = 0.06). Conclusiones: Restrictive dysfunction presented a lower survival rate than BOS. GER was associated with restrictive rejection. Chest tomography differs in both types of chronic rejection.

Upregulation of microRNA 142-3p in the peripheral blood and urinary cells of kidney transplant recipients with post-transplant graft dysfunction

We analyzed microRNA (miR)-142-3p expression in leucocytes of the peripheral blood and urinary sediment cell samples obtained from kidney transplant recipients who developed graft dysfunction. Forty-one kidney transplant recipients with kidney graft dysfunction and 8 stable patients were included in the study. The groups were divided according to histological analysis into acute rejection group (n=23), acute tubular necrosis group (n=18) and stable patients group used as a control for gene expression (n=8). Percutaneous biopsies were performed and peripheral blood samples and urine samples were obtained. miR-142-3p was analyzed by real-time polymerase chain reaction. The group of patients with acute tubular necrosis presented significantly higher expressions in peripheral blood (P<0.05) and urine (P<0.001) compared to the stable patients group. Also, in the peripheral blood, miR-142-3p expression was significantly higher in the acute tubular necrosis group compared to the acute rejection group (P<0.05). Urine samples of the acute rejection group presented higher expression compared to the stable patients group (P<0.001) but the difference between acute tubular necrosis and acute rejection groups was not significant in the urinary analyzes (P=0.079). miR-142-3p expression has a distinct pattern of expression in the setting of post-operative acute tubular necrosis after kidney transplantation and may potentially be used as a non-invasive biomarker for renal graft dysfunction.

The role of bradykinin in lung ischemia-reperfusion injury in a rat lung transplantation model

ABSTRACT PURPOSE: To investigate the role of bradykinin in a rat lung transplantation (LTx) model and preliminarily discuss the relationship between bradykinin and CD26/DPP-4. METHODS: Rats were randomly divided into four groups: Control (CON), Sham, low potassium dextranglucose (LPD), and AB192 (n=15/group). Orthotopic single LTx was performed in the LPD and AB192 groups. The donor lungs were flush-perfused and preserved with low potassium dextranglucose (LPD) or LPD+CD26/DPP-4 catalytic inhibitor (AB192). LTx was performed after 18 h cold ischemia time and harvested two days post-LTx. Blood gas analysis (PO2), wet/dry weight ratio (W/D), myeloperoxidase activity (MPO), and lipid peroxidation (MDA) were analyzed at 48 hr after transplantation. Immunohistochemical (IHC) analysis was performed in the same sample and validated by Western-Blot. RESULTS: Compared to the LPD group, the AB192 group showed higher PO2, lower W/D ratio, and decreased MPO and MDA. IHC studies showed strong bradykinin β2 receptor (B2R) staining in the LPD group, especially in inflammatory cells, alveolar macrophages, and respiratory epithelial cells. Expression of B2R by Western-Blot was significantly different between the AB192 and LPD groups. CONCLUSION: Bradykinin may be a competitive substrate of DPP-4, and decreased bradykinin levels may enhance protective effects against ischemia/reperfusion injury during LTx.

Transforming growth factor-β in graft vessels: histology and immunohistochemistry

OBJECTIVES: The biological functions of transforming growth factor-β signaling that involves Smad proteins have not been previously investigated with respect to coronary artery bypass grafts. The aim of the present study was to observe the immunostaining of proteins that are related to this signaling pathway. METHODS: Fifteen remnants of coronary artery bypass grafts, including nine saphenous veins, three radial arteries and three mammary arteries, were collected from 12 patients who were undergoing coronary artery bypass. Hematoxylin and eosin, Masson's trichrome, and immunohistochemical staining of transforming growth factor-β1, type I receptor of transforming growth factor-β, Smad2/3, Smad4, and Smad7 were performed. RESULTS: The saphenous veins showed more severe intimal degeneration, more severe smooth muscle cell proliferation and more collagen deposition than the arterial grafts, as evidenced by hematoxylin and eosin and Masson's trichrome stainings. Immunohistochemical assays demonstrated that the majority of the transforming growth factor-β1 signaling cytokines were primarily localized in the cytoplasm in the medial layers of all three types of grafts, whereas ectopic transforming growth factor-β1, type I receptor of transforming growth factor-β, and Smad7 overexpressions in the interstices were observed particularly in the saphenous vein and radial arterial grafts. CONCLUSION: Enhanced transforming growth factor-β1 signal transduction with medial smooth muscle cell proliferation and ectopic transforming growth factor-β1, the presence of the type I receptor of transforming growth factor-β, and Smad7 overexpressions in the extracellular matrix may provide primary evidence for early or late graft failure.