Imaging of Lung in Following Stem Cell Therapy in The Preclinical Study

Background and Aim: Acute respiratory distress syndrome has a poorprognosis. ARDS is a non-homogeneous combination of different disorders sharing some clinical and radiological abnormalities andrequiring the development of novel therapies. Radiographic findings ofARDS are non-specific and cannot identify it from typical pulmonaryedema or hemorrhage. Chest x-ray features usually develop 24 hoursafter initial lung damage. In contrast to cardiogenic pulmonary edema,ARDS persists for days to weeks so that ct-scan plays key role in thefindings of ARDS depend on the phase of the disease and can help us indiagnosis and treatments.Methods: Adult Sall sheep (10 male) were selected and divided intotwo groups. In the treatment group, bone marrow stem cell (BM-MSC)was isolated and expanded. An experimental model of ARDS wasinduced by endotracheal endotoxin of E. coli strains-O55: B5 infusionand confirmed after 24 hours of ARDS-induce, 5×107 cells/sheep wereaoutologically engrafted with the tracheal catheter. For evaluate effectsof cell therapy, the thoracic computerized tomography (CT-scan) fromthe lung of all anesthetized sheep was taken by the aid of Somaris Spiritclass II (Siemens) before and at 12, 24, 48, 72 and 168 hours after MSCstransplantation or PBS infusion. Quantitative estimation was done fordifferent adjacent CT sections with Siemens Leonardo workstation andsoftware tools. Lung parenchymal margin was manually demarcated andthen average Hounsfield unit and volume obtained for each section.Results: Hounsfield unit and volumes of the aerated and non-aeratedarea of right and left lungs were measurements in CT-scan images.The measure demonstrated the Hounsfield unit had increased one dayafter ARDS inducing that the present’s replacement air with mucus andinflammatory cells. A significant decrease in the Hounsfield unit foundat hours of 168 (P=0.028) post-transplantation in the treatment groupcompared with inflammation time and in 72 (P=0.012) and 168 (P=0.036)times compared with the control group. Also, variation volumes werecompared and showed that total lung volume in both groups increasedafter inflammation, but transplantation of BM-MSCs had decreased theprocess at 168 (P=0.013) time in compared with inflammation time andat 72 (P=.030) and 168h (P=0.011) times compared with control group.In the acute phase of ARDS, CT scans typically show a non-homogeneousdistribution and a ventrodorsal gradient of density.Conclusion: CT scans were provided additional information that notobvious on bedside chest radiographs and led to a change in managementin animal modeling. Moreover, CT was helped us to understand thepathophysiology of ARDS and the complex interplay between lungparenchyma and mechanical ventilation. According to our findings, aCT scan will be able to follow and integrate clinical evolution of celltreatment in ARDS, and it is certainly a worthwhile data.

کلیدواژه ها:

ARDS ، CT-scan ، Stem cell therapy