Meet in the middle: Could cell mediated-immunity assays be the answer for ideal Cytomegalovirus prophylaxis after lung transplantation? Observational study from a single center with intermittent antiviral prophylaxis.

BACKGROUND: Cytomegalovirus (CMV) can cause tissue-invasive disease and indirect effects after lung transplantation (LTx) such as acute rejection episodes and chronic lung allograft dysfunction. Monitoring CMV-specific cell immune recovery (CMV-CIR) after LTx can individualize CMV risks and establish better antiviral approach. This study evaluated the dynamics of CMV-CIR, using QuantiFERON-CMV assay (Qiagen Group), in the first year after LTx. METHODS: Prospective observational cohort study included lung transplant recipients from December/2015 to December/2016. Universal antiviral prophylaxis with intravenous ganciclovir 5 mg/kg/day 3 days/week for 3 months was given for CMV-seropositive recipients (R+) and only CMV-seropositive donor and negative recipient (D+/R-) received a 6-month-prophylaxis with ganciclovir and valganciclovir, on alternate days, in the first 3 months and then, 3 more months of valganciclovir. QuantiFERON-CMV was measured at the same time points of surveillance bronchoscopies. CMV infection was defined as any DNAemia detected and CMV disease with proven biopsy or antigenemia pp65 above 10 cells/300.000 neutrophils. RESULTS: Thirty-eight patients were included. On days 45, 90, and 365 days post-LTx, 60%, 72%, and 81% QuantiFERON-CMV were reactive, respectively. Eleven patients (28.9%) presented CMV-disease and 27 DNAemia/CMV infections. Reactive tests were able to predict CMV disease only at 90 days after LTx (p = .027) but failed on DNAemia/CMV infection (p = .148). Daily prophylaxis, for D+/R- patients (13.2%), remained as an independently associated factor for not achieving reactive QuantiFERON-CMV (adjusted OR .27, 95%CI .12-.60, p = .02). CONCLUSION: QuantiFERON-CMV may be another diagnostic tool to help stratify CMV-disease risk and individualized antiviral prophylaxis after LTx.

Indications for lung resection surgery and lung transplant in South American children with cystic fibrosis.

The current available literature evaluating lung resection surgery and lung transplantation in children with cystic fibrosis (CF) was reviewed through a PubMed search and references from selected studies were additionally included. Pulmonary resections, i.e. lobectomy, segmentectomy, and pneumonectomy, are seldom performed in CF. The main indications, in patients with a forced expiratory volume in 1second (FEV1) that is greater than 30% predicted, are localized bronchiectasis/atelectasis, severe hemoptysis, and bronchopleural fistula refractory to medical management. The potential benefits are decreased symptoms and pulmonary exacerbations, and an improved quality of life. Pre and postoperative intensive care is mandatory for surgical candidates. The risk of death should be taken into account when the procedure is considered. Selection for lung transplantation (LTx) candidates in children with CF in South America follows the International Society for Heart and Lung Transplantation (ISHLT) criteria. When compared to adults with CF, a poorer survival rate after LTx in children with CF has been observed in the literature, as well as in our LTx center in Brazil, reasons for which are still unknown. The main complications after LTx in children are early and late acute rejection, and infections. LTx is a therapeutic option for eligible children with CF, fulfilling the lung transplant candidacy criteria, as post-transplant survival rates are increasingly improving due to better management of the transplanted patient.

Experience of Lung Transplantation in Patients with Lymphangioleiomyomatosis at a Brazilian Reference Centre.

INTRODUCTION: Lung transplantation (LT) is the standard of care for patients with advanced lung diseases, including lymphangioleiomyomatosis (LAM). LAM accounts for only 1% of all LTs performed in the international registry. As a result, the global experience, including the use of mechanistic target of rapamycin (mTOR) inhibitors before and after LT in LAM, is still limited. METHODS: We conducted a retrospective review of all LAM patients who underwent LT at our centre between 2003 and 2016. Pre- and post-transplant data were assessed. RESULTS: Eleven women with LAM underwent LT, representing 3.3% of all procedures. Ten (91%) patients underwent double-LT. The mean age at diagnosis was 39 ± 6 years and the mean FEV1 before LT was 28 ± 14%. Only one patient underwent pleurodesis for recurrent pneumothorax. Pulmonary hypertension was confirmed in 3 (27%) patients. Four (36%) patients received sirolimus preoperatively; three of them received it until the day of LT, and there was no occurrence of bronchial anastomotic dehiscence after the procedure. Four patients (36%) received mTOR inhibitors post-transplant. The median follow-up from LT was 44 months. There were 3 deaths (27%) during the study and survival probabilities at 1, 3, and 5 years after LT were, 90, 90, and 77%, respectively. CONCLUSIONS: This data reinforces the role of LT for LAM patients with end-stage disease. The use of sirolimus seems to be safe before LT and the occurrence of complications after LT, including those LAM-related, should be continuously monitored.

[The association between red cell distribution width (RDW) and short-term mortality risk in patients with acute coronary syndrome (ACS)]. / Relación entre el ancho de distribución eritrocitaria (ADE) y la mortalidad a corto plazo en pacientes con síndrome coronario agudo (SCA).

OBJECTIVE: To demonstrate the association between red cell distribution width and short-term mortality risk in patients with acute coronary syndrome. METHODS: We prospectively recruited 78 patients with acute coronary syndrome. The study population was classified according to quartiles of the red cell distribution width at hospital admission. A high red cell distribution width was defined as a value in the upper fourth quartile (>15) and a low red cell distribution width was defined as any value set in the lower three quartiles (≤15). After discharge, all patients were followed for three months. RESULTS: The short-term cardiovascular mortality was 47.2% in the high red cell distribution width group vs. 10.2% in the low red cell distribution width group (p<0.001). In the receiver operating characteristic curve analysis, a red cell distribution width value of more than 15% yielded a sensitivity of 66.7%, a specificity of 83%, and a positive predictive value of 79.7% for cardiac mortality. After multivariate analysis, high levels of red cell distribution width were independent predictors for three-month mortality (p=0.001). CONCLUSION: We demonstrated that red cell distribution width is an accessible parameter associated with short-term cardiovascular mortality in patients with acute coronary syndrome.

Interaction of apurinic/apyrimidinic endonucleases Nfo and ExoA with the DNA integrity scanning protein DisA in the processing of oxidative DNA damage during Bacillus subtilis spore outgrowth.

Oxidative stress-induced damage, including 8-oxo-guanine and apurinic/apyrimidinic (AP) DNA lesions, were detected in dormant and outgrowing Bacillus subtilis spores lacking the AP endonucleases Nfo and ExoA. Spores of the Δnfo exoA strain exhibited slightly slowed germination and greatly slowed outgrowth that drastically slowed the spores' return to vegetative growth. A null mutation in the disA gene, encoding a DNA integrity scanning protein (DisA), suppressed this phenotype, as spores lacking Nfo, ExoA, and DisA exhibited germination and outgrowth kinetics very similar to those of wild-type spores. Overexpression of DisA also restored the slow germination and outgrowth phenotype to nfo exoA disA spores. A disA-lacZ fusion was expressed during sporulation but not in the forespore compartment. However, disA-lacZ was expressed during spore germination/outgrowth, as was a DisA-green fluorescent protein (GFP) fusion protein. Fluorescence microscopy revealed that, as previously shown in sporulating cells, DisA-GFP formed discrete globular foci that colocalized with the nucleoid of germinating and outgrowing spores and remained located primarily in a single cell during early vegetative growth. Finally, the slow-outgrowth phenotype of nfo exoA spores was accompanied by a delay in DNA synthesis to repair AP and 8-oxo-guanine lesions, and these effects were suppressed following disA disruption. We postulate that a DisA-dependent checkpoint arrests DNA replication during B. subtilis spore outgrowth until the germinating spore's genome is free of damage.

Anaplastic Lymphoma Kinase (ALK)-Negative Anaplastic Large Cell Non-Hodgkin Lymphoma as a Rare Differential Diagnosis of Lung Cancer: A Case Report.

Anaplastic large cell lymphomas (ALCL) are a group of sporadic malignancies that generally have an aggressive clinical course, especially the subtype of anaplastic lymphoma kinase (ALK)-negative ALCL. The appropriate diagnostic study modalities must be chosen to make an accurate diagnosis and promptly initiate specific treatment. We present the clinical case of a 72-year-old male patient with dyspnea on small efforts accompanied by diaphoresis and a weight loss of 10 kg in two months. Physical examination revealed adenopathy in the cervical region and bilateral pleural effusion. The pleural and lung biopsies revealed poorly differentiated metastatic adenocarcinomas. A multidisciplinary analysis was carried out; the typical clinical-radiographic presentation of adenocarcinoma was ruled out with immunohistochemistry, thus determining a diagnosis of ALK-negative anaplastic large cell non-Hodgkin's lymphoma. This case represented a diagnostic and therapeutic challenge since it is a rare entity with a poor prognosis, and there are only a few studies about the choice of appropriate chemotherapy in these patients.

Characteristics of tracheostomized patients followed up by a Palliative Care and Complex Chronic Patient Service.

INTRODUCTION AND OBJECTIVES: In recent years, there has been an increase in the number of children with tracheostomies. The objective was to describe the characteristics of paediatric patients with a tracheostomy followed up by the Department of Palliative Care and Chronic Medically Complex Illness (DPCCMCI) of a tertiary care hospital. METHODS: Single-centre retrospective observational study in patients aged less than 18 years with a tracheostomy followed up by the PCCCPS of a tertiary care hospital (November 2020-June 2022). We analysed epidemiological, clinical, microbiological and social data by reviewing the health records. RESULTS: The sample included 44 tracheostomized patients. The most frequent underlying disease was acquired upper airway disease (20.5%). The most common indication for tracheostomy was upper airway obstruction (66%). Bacterial isolates were detected in 84% of the tracheal aspirates, among which P. aeruginosa was the most frequent (56.8%). The most frequently prescribed antibiotic was ciprofloxacin (84%). In addition, 18.1% of the patients received at least 1 course of intravenous antibiotherapy and 29.5% received more than 3 systemic antibiotic regimens in the past 20 months. Fifty-nine percent of the children were schooled: 38.6% attended a regular school, 15.9% a special needs school and 4.5% were home-schooled. We identified social difficulties in 53.7%. Also, 22.7% of the families received financial support to care for a child with severe illness. CONCLUSIONS: Because of the complexity of caring for tracheostomized children, integral and coordinated management is essential. Schooling is possible and safe if caregivers are trained.

Usual interstitial pneumopathy in a patient with hypersensitivity pneumonitis and microscopic polyangiitis. Case report.

One of the most frequent diffuse interstitial lung diseases is hypersensitivity pneumonitis. It is related to exposure to diverse antigens, causing fibrosis in advanced stages, making the differential diagnosis with interstitial pulmonary fibrosis difficult as it overlaps with the usual interstitial pneumonia pattern. On the other hand, there are interstitial lung diseases associated with ANCA, such as microscopic polyangiitis, which is also related to the usual interstitial pneumonia pattern. We present the case of a 74-year-old male patient with chronic dyspnea, history of smoking and exposure to organic particles, in addition to a pattern suggestive of moderately severe restriction. The diagnosis was confirmed by histology of hypersensitivity pneumonitis by presenting granules, however, anti MPO and p-ANCA positivity was found, integrating the simultaneous diagnosis of microscopic polyangiitis. This is a case of difficult diagnosis since these pathologies have not been previously reported to coexist.

Obesity hypoventilation syndrome, literature review.

Obesity is a global health concern that has been increasing over the years, and it is associated with several pathophysiological changes affecting the respiratory system, including alveolar hypoventilation. Obesity hypoventilation syndrome (OHS) is one of the six subtypes of sleep-hypoventilation disorders. It is defined as the presence of obesity, chronic alveolar hypoventilation leading to daytime hypercapnia and hypoxia, and sleep-disordered breathing. The existence of a sleep disorder is one of the characteristics that patients with OHS present. Among them, 90% of patients have obstructive sleep apnea (OSA), and the remaining 10% of patients with OHS have non-obstructive sleep hypoventilation without OSA or with mild OSA. This review aims to provide a comprehensive understanding of the epidemiological and pathophysiological impact of OHS and to highlight its clinical features, prognosis, and severity, as well as the available treatment options.

Cellular and biochemical characterization of two closely related triosephosphate isomerases from Trichomonas vaginalis.

The glycolytic enzyme triosephosphate isomerase catalyses the isomerization between glyceraldehyde 3-phosphate and dihydroxyacetone phosphate. Here we report that Trichomonas vaginalis contains 2 fully functional tpi genes. Both genes are located in separated chromosomal context with different promoter regulatory elements and encode ORFs of 254 amino acids; the only differences between them are the character of 4 amino acids located in α-helices 1, 2 and 8. Semi-quantitative RT-PCR assays showed that tpi2 transcript is approximately 3·3-fold more abundant than tpi1. Using an anti-TvTIM2 polyclonal antibody it was demonstrated that TIM proteins have a cytoplasmic localization and both enzymes are able to complement an Escherichia coli strain carrying a deletion of its endogenous tpi gene. Both TIM proteins assemble as dimers and their secondary structure assessment is essentially identical to TIM from Saccharomyces cerevisiae. The kinetic catalytic constants of the recombinant enzymes using glyceraldehyde-3-phosphate as substrate are similar to the catalytic constants of TIMs from other organisms including parasitic protozoa. As T. vaginalis depends on glycolysis for ATP production, we speculate 2 possible reasons to maintain a duplicated tpi copy on its genome: an increase in gene dosage or an early event of neofunctionalization of TIM as a moonlighting protein.

Lipid fraction quality of milk produced by Minhota (Portuguese autochthonous breed) compared to Holstein Friesian cow's.

BACKGROUND: Minhota and Holstein Friesian cows (15 from each breed) were selected from several farms located in the north of Portugal, all under similar feeding regime. Milk samples from individual cows were collected once a month, during one year, to take into account different lactation stages and feeding seasonal changes. RESULTS: Holstein milk was found to have higher content of total polyunsaturated fatty acids, omega-6, and trans fatty acids, while Minhota milk had significantly higher monounsaturated fatty acids content. No statistical differences were observed for omega-3 and saturated fatty acids contents, mostly due to the high dispersion observed in Minhota milk samples. The average amount of conjugated linoleic acid was higher in Minhota breed, but the high dispersion of values reduced the statistical significance. Cholesterol content, expressed as mg kg(-1) of fat, was higher in Holstein than in Minhota milk. CONCLUSION: The results indicate that Minhota milk has important nutritional qualities that deserve attention, but the wide individual variation found within animals from this breed suggests a high genetic variability. Following this, the selection of some of these animals for intensive milk production could improve milk quality.

Flexible broncoscopy in patients in supportive therapy with oxygenation by extracorporeal membrane.

OBJECTIVE: To report the experience of performing bronchoscopy in patients who underwent supportive therapy with extracorporeal membrane oxygenation in whom the bronchoscopy was performed. METHODS: This was a review of medical records of patients diagnosed with extracorporeal membrane oxygenation and who required diagnostic or therapeutic bronchoscopy. Records included were related to patients admitted to the intensive care unit of Hospital das Clínicas of Faculdade de Medicina of Universidade de São Paulo, between 2014 and 2020. RESULTS: During the study, 16 bronchoscopies were performed in 8 patients admitted to the intensive care unit and who underwent supportive therapy with extracorporeal membrane oxygenation. The mean age of patients was 28.37 years. Four patients were women (50%). A total of 5 (31.25%) therapeutic bronchoscopies and 11 (68.75%) diagnostics were performed. In 5 of patients, material was collected: 4 samples of bronchoalveolar lavage, three collections of transbronchial biopsies, and 1 of endobronchial biopsies. No patient had radiological worsening or hemodynamic complications. One patient (6.25%) had transient desaturation. There was moderate bleeding after transbronchial biopsy in 1 (6.25%) procedure, which was resolved endoscopically. CONCLUSION: Patients undergoing extracorporeal membrane oxygenation can safely perform diagnostic or therapeutic bronchoscopy provided that they have a detailed indication. Procedures were performed by a specialized bronchoscopy team in intensive care environment and with the assistance of a qualified multidisciplinary team in membrane oxygenation therapy extracorporeal.

Humoral response to SARS-CoV-2 after vaccination and booster effect in patients undergoing dialysis.

OBJECTIVE: The aim of this study was to determine and evaluate the postvaccination variation in immunoglobulin G (IgG) receptor-binding domain (RBD) produced in non-SARS-CoV-2-infected patients with nephropathy and renal replacement therapy. METHODS: This is a follow-up study of the humoral response to the BNT162b2 messenger ribonucleic acid COVID-19 vaccine in patients with nephropathy, comparing it with itself at different times and with the healthy population. RESULTS: In patients with nephropathy, a very striking decrease in IgG RBD was observed compared with the healthy population (P<0.001) at three months after the second dose. In patients with nephropathy, the response rate ≥590 binding antibody units/ml (4154 AU/ml) was detected in 45% of patients, 15 days after the second dose, whereas at 3 months, this decreased to 9% (P<0.05) and then increased to 86% after the third dose (P<0.001). CONCLUSION: In patients with nephropathy and renal replacement therapy, it is necessary to administer a third-dose vaccination within 3 months after the second dose. It is important to continue monitoring the humoral response to obtain a better SARS-CoV-2 vaccination schedule.

A Physiotherapy Treatment Plan for Post-COVID-19 Patients That Improves the FEV1, FVC, and 6-Min Walk Values, and Reduces the Sequelae in 12 Sessions.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causal agent of Coronavirus disease 2019 (COVID-19), a pandemic disease declared in 2020. The clinical manifestations of this pathology are heterogeneous including fever, cough, dyspnea, anosmia, headache, fatigue, taste dysfunction, among others. Survivors of COVID-19 have demonstrated several persistent symptoms derived from its multisystemic physiopathology. These symptoms can be fatigue, dyspnea, chest pain, dry and productive cough, respiratory insufficiency, and psychoemotional disturbance. To reduce and recover from the post-COVID-19 sequelae is fundamental an early and multifactorial medical treatment. Integral post-COVID-19 physiotherapy is a tool to reduce dyspnea, improve lung capacity, decrease psychoemotional alterations, as well as increase the muscle strength affected by this disease. Thus, the aim of this study was to establish a novel physiotherapeutic plan for post-COVID-19 patients, evaluating the effect of this treatment in the reduction of the sequelae in terms of lung capacity, cardio-respiratory, and muscular strength improvements. This was a cross-sectional study in which a protocol of 12 sessions in 4 weeks of physiotherapy was implemented in the patients enrolled. We conducted a medical assessment, an interview, a DASS-21 test, a spirometry, a 6-min walk test, and a hand dynamometer test to evaluate the post-COVID condition of patients before and after the sessions. A total of 42 patients participated in the program. Results of this work showed a decrease of around 50% of post-COVID-19 sequelae and an improvement in the psychoemotional status of patients. Also, we observed an increase of 7.16% in the FEV1 value and 7.56% for FVC. In addition, the maximal functional capacity increased by 0.577 METs, the 6-min walk test performance increased by 13%, and the SpO2 improved by 1.40%. Finally, the handgrip strength test showed an improvement in the left hand and right hand of 2.90 and 2.24 Kg, respectively. We developed this study to propose a novel methodology to provide information for a better treatment and management of post-COVID-19 patients.

Brazilian initial experience with lung transplantation due to irreversible lung fibrosis post-COVID-19 in a national reference center: a cohort study.

BACKGROUND: Lung transplantation (LTx) has been discussed as an option for treating irreversible lung fibrosis post-coronavirus disease 2019 (COVID-19), in selected cases. OBJECTIVES: To report on the initial experience and management of end-stage lung disease due to COVID-19 at a national center reference in Brazil. DESIGN AND SETTING: Cohort study conducted at a national reference center for lung transplantation. METHODS: Medical charts were reviewed regarding patients' demographics and pre-COVID-19 characteristics, post-LTx due to COVID-19. RESULTS: Between March 2020 and September 2021, there were 33 cases of LTx. During this period, we evaluated 11 cases of severe COVID-19-related acute respiratory distress syndrome (ARDS) that were potentially candidates for LTx. Among these, LTx was only indicated for three patients (9.1%). All of these patients were on venovenous extracorporeal membrane oxygenation (ECMO), and the procedure that they underwent was central venoarterial ECMO. All three patients were still alive after the first 30 postoperative days. However, patient #1 and patient #2 subsequently died due to fungal sepsis on the 47th and 52nd postoperative days, respectively. Patient #3 was discharged on the 30th postoperative day. CONCLUSIONS: LTx is feasible among these complex patients. Survival over the first 30 days was 100%, and this favors surgical feasibility. Nonetheless, these were critically ill patients.

Consensus document for the selection of lung transplant candidates: An update from the International Society for Heart and Lung Transplantation.

Tens of thousands of patients with advanced lung diseases may be eligible to be considered as potential candidates for lung transplant around the world each year. The timing of referral, evaluation, determination of candidacy, and listing of candidates continues to pose challenges and even ethical dilemmas. To address these challenges, the International Society for Heart and Lung Transplantation appointed an international group of members to review the literature, to consider recent advances in the management of advanced lung diseases, and to update prior consensus documents on the selection of lung transplant candidates. The purpose of this updated consensus document is to assist providers throughout the world who are caring for patients with pulmonary disease to identify potential candidates for lung transplant, to optimize the timing of the referral of these patients to lung transplant centers, and to provide transplant centers with a framework for evaluating and selecting candidates. In addition to addressing general considerations and providing disease specific recommendations for referral and listing, this updated consensus document includes an ethical framework, a recognition of the variability in acceptance of risk between transplant centers, and establishes a system to account for how a combination of risk factors may be taken into consideration in candidate selection for lung transplantation.

Rapid diagnosis and quantification of acute kidney injury using fluorescent ratio-metric determination of glomerular filtration rate in the rat.

The rapid diagnosis and quantification of acute kidney injury (AKI) severity remain high clinical priorities. By combining intravital fluorescent ratiometric two-photon kidney imaging and the two-compartment pharmacokinetics model, we demonstrate that rapid quantification of glomerular filtration rate (GFR) can be achieved in physiologic and AKI rat kidney models. Using a bolus infusion of a mixture of FITC-inulin and a 500-kDa Texas Red dextran, a full spectrum of GFR values, ranging from 0.17 to 1.12 ml·min(-1)·100 g(-1), was obtained. The GFR values thus determined correlated well with values obtained by the standard 2-h inulin infusion clearance method with a Pearson's correlation coefficient of 0.85. In addition, postischemia deterioration was studied by measuring GFR using the two-photon approach during 24 h following a 45-min bilateral ischemia clamp model. The GFR was found to decline sharply during the initial 4 h followed by a nadir with little sign of rising over the ensuing 24-h period. Moreover, a FITC-labeled 5-kDa dextran was identified as having nearly identical filtration characteristics as FITC-inulin, but had markedly increased fluorescent intensity, thus minimizing the quantity needed for individual studies. The technique reported allows for very rapid GFR determinations, within 10-15 min, based on plasma clearance of a freely filtered fluorescence probe, instead of a prolonged one-compartment interstitial space reporter molecule clearance employed by other technologies.

Impaired tubular uptake explains albuminuria in early diabetic nephropathy.

Understanding the pathogenesis of albuminuria in diabetic nephropathy is important to improve methods for early diagnosis and treatment. In this study, we addressed whether albuminuria in diabetes results from altered glomerular filtration and/or altered processing of filtered albumin by the proximal tubule. Type 1 diabetic Munich Wistar rats developed albuminuria after 12 wk of diabetes. Intravital two-photon microscopy revealed similar glomerular permeability in the diabetic and control animals, assessed using both albumin-Alexa568 and 69-kD FITC-dextran; however, diabetic animals demonstrated significantly less filtered fluorescent albumin in renal proximal tubule (PT) cells compared with control animals. We also observed increased albumin-derived urinary peptide excretion in diabetic animals, and hyperglycemia modulated this peptideuria. In conclusion, in the early stages of diabetic nephropathy, the PT plays a major role in the development of albuminuria, which may be preceded by peptideuria.

Soluble thrombomodulin protects ischemic kidneys.

Altered coagulation and inflammation contribute to the pathogenesis of ischemic renal injury. Thrombomodulin is a necessary factor in the anticoagulant protein C pathway and has inherent anti-inflammatory properties. We studied the effect of soluble thrombomodulin (sTM) in a hypoperfusion model of ischemic kidney injury. To markedly reduce infrarenal aortic blood flow and femoral arterial pressures, we clamped the suprarenal aorta of rats, occluding them 90%, for 60 min. Reversible acute kidney injury (AKI) occurred at 24 h in rats subjected to hypoperfusion. Histologic analysis at 24 h revealed acute tubular necrosis (ATN), and intravital two-photon microscopy showed flow abnormalities in the microvasculature and defects of endothelial permeability. Pretreatment with rat sTM markedly reduced both I-R-induced renal dysfunction and tubular histologic injury scores. sTM also significantly improved microvascular erythrocyte flow rates, reduced microvascular endothelial leukocyte rolling and attachment, and minimized endothelial permeability to infused fluorescence dextrans, assessed by intravital quantitative multiphoton microscopy. Furthermore, sTM administered 2 h after reperfusion protected against ischemia-induced renal dysfunction at 24 h and improved survival. By using an sTM variant, we also determined that the protective effects of sTM were independent of its ability to generate activated protein C. These data suggest that sTM may have therapeutic potential for ischemic AKI.