Outcome and Prognostic Indicators of Patients with Hematopoietic Stem Cell Transplants Admitted to the Intensive Care Unit

The prognosis of patients with hematopoietic stem cell transplants (HSCTs) who require admission to the intensive care unit (ICU) has been regarded as extremely poor. We sought to re-evaluate recent outcomes and predictive factors in a retrospective cohort study. Among the 605 adult patients that received an HSCT between 2001 and 2006, 154 required admission to the ICU. Of these, 47% were discharged from the ICU, 36% were discharged from the hospital, and 19% survived 6 months. Allogeneic transplant, mechanical ventilation, vasopressor-use, and neutropenia were each associated with increased mortality, and the mortality of patients with all four characteristics was 100%. Hemodialysis was also associated with increased mortality in a Kaplan-Meier analysis but did not appear important in a multivariate tree analysis. A final Cox model confirmed that allogeneic transplant, mechanical ventilation, and vasopressor-use were each independent risk factors for mortality in the 6 months following ICU admission

Usefulness of gene expression profiling of bronchoalveolar lavage cells in acute lung allograft rejection.

BackgroundChronic lung allograft dysfunction (CLAD) is the main limitation to long-term survival after lung transplantation. Because effective therapies are lacking, early identification and mitigation of risk factors is a pragmatic approach to improve outcomes. Acute cellular rejection (ACR) is the most pervasive risk factor for CLAD, but diagnosis requires transbronchial biopsy, which carries risks. We hypothesized that gene expression in the bronchoalveolar lavage (BAL) cell pellet (CP) could replace biopsy and inform on mechanisms of CLAD.MethodsWe performed RNA sequencing on BAL CPs from 219 lung transplant recipients with A-grade ACR (n = 61), lymphocytic bronchiolitis (n = 58), infection (n = 41), or no rejection/infection (n = 59). Differential gene expression was based on absolute fold difference >2.0 and Benjamini-adjusted p-value ≤0.05. We used the Database for Annotation, Visualization and Integrated Discovery Bioinformatics Resource for pathway analyses. For classifier modeling, samples were randomly split into training (n = 154) and testing sets (n = 65). A logistic regression model using recursive feature elimination and 5-fold cross-validation was trained to optimize area under the curve (AUC).ResultsDifferential gene expression identified 72 genes. Enriched pathways included T-cell receptor signaling, natural killer cell-mediated cytotoxicity, and cytokine-cytokine receptor interaction. A 4-gene model (AUC = 0.72) and classification threshold defined in the training set exhibited fair performance in the testing set; accuracy was 76%, specificity 82%, and sensitivity 60%. In addition, classification as ACR was associated with worse CLAD-free survival (hazard ratio = 2.42; 95% confidence interval = 1.29-4.53).ConclusionsBAL CP gene expression during ACR is enriched for immune response pathways and shows promise as a diagnostic tool for ACR, especially ACR that is a precursor of CLAD

CXCR2 is critical for dsRNA-induced lung injury: relevance to viral lung infection

BACKGROUND: Respiratory viral infections are characterized by the infiltration of leukocytes, including activated neutrophils into the lung that can lead to sustained lung injury and potentially contribute to chronic lung disease. Specific mechanisms recruiting neutrophils to the lung during virus-induced lung inflammation and injury have not been fully elucidated. Since CXCL1 and CXCL2/3, acting through CXCR2, are potent neutrophil chemoattractants, we investigated their role in dsRNA-induced lung injury, where dsRNA (Poly IC) is a well-described synthetic agent mimicking acute viral infection. METHODS: We used 6–8 week old female BALB/c mice to intratracheally inject either single-stranded (ssRNA) or double-stranded RNA (dsRNA) into the airways. The lungs were then harvested at designated timepoints to characterize the elicited chemokine response and resultant lung injury following dsRNA exposure as demonstrated qualititatively by histopathologic analysis, and quantitatively by FACS, protein, and mRNA analysis of BAL fluid and tissue samples. We then repeated the experiments by first pretreating mice with an anti-PMN or corresponding control antibody, and then subsequently pretreating a separate cohort of mice with an anti-CXCR2 or corresponding control antibody prior to dsRNA exposure. RESULTS: Intratracheal dsRNA led to significant increases in neutrophil infiltration and lung injury in BALB/c mice at 72 h following dsRNA, but not in response to ssRNA (Poly C; control) treatment. Expression of CXCR2 ligands and CXCR2 paralleled neutrophil recruitment to the lung. Neutrophil depletion studies significantly reduced neutrophil infiltration and lung injury in response to dsRNA when mice were pretreated with an anti-PMN monoclonal Ab. Furthermore, inhibition of CXCR2 ligands/CXCR2 interaction by pretreating dsRNA-exposed mice with an anti-CXCR2 neutralizing Ab also significantly attenuated neutrophil sequestration and lung injury. CONCLUSION: These findings demonstrate that CXC chemokine ligand/CXCR2 biological axis is critical during the pathogenesis of dsRNA-induced lung injury relevant to acute viral infections

CXC chemokines in angiogenesis

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141036/1/jlb0001.pd

Stromal Derived Factor-1 (SDF-1/CXCL12) and CXCR4 in renal cell carcinoma metastasis

Renal cell carcinoma (RCC) is characterized by organ-specific metastases. The chemokine stromal derived factor-1 (SDF-1/CXCL12) and its receptor CXCR4 have been suggested to regulate organ-specific metastasis in various other cancers. On this basis, we hypothesized that the biological axis of CXCL12 via interaction with its receptor, CXCR4, is a major mechanism for RCC metastasis. We demonstrated that CXCR4 was significantly expressed on circulating cytokeratin+ RCC cells from patients with known metastatic RCC. We detected up-regulation of CXCR4 mRNA and protein levels on a human RCC cell line by either knockdown of the von Hippel-Lindau (VHL) tumor suppressor protein, or incubating the cells under hypoxic conditions. The enhanced CXCR4 expression was mediated through the interaction of the Hypoxia Inducible Factor-1α (HIF-1α) with the promoter region of the CXCR4 gene. Furthermore, the expression of CXCR4 on human RCC directly correlated with their metastatic ability in vivo in both heterotopic and orthotopic SCID mouse models of human RCC. Neutralization of CXCL12 in SCID mice abrogated metastasis of RCC to target organs expressing high levels of CXCL12; without altering tumor cell proliferation, apoptosis, or tumor-associated angiogenesis. Therefore, our data suggest that the CXCL12/CXCR4 biological axis plays an important role in regulating the organ-specific metastasis of RCC

Quantification of Cytokeratin 5 mRNA Expression in the Circulation of Healthy Human Subjects and after Lung Transplantation

Circulating epithelial progenitor cells are important for repair of the airway epithelium in a mouse model of tracheal transplantation. We therefore hypothesized that circulating epithelial progenitor cells would also be present in normal human subjects and could be important for repair of the airway after lung injury. As lung transplantation is associated with lung injury, which is severe early on and exacerbated during episodes of infection and rejection, we hypothesized that circulating epithelial progenitor cell levels could predict clinical outcome following lung transplantation.Quantitative Real Time PCR was performed to determine peripheral blood mRNA levels of cytokeratin 5, a previously characterized marker of circulating epithelial progenitor cells. Cytokeratin 5 levels were evaluated in healthy human subjects, in lung transplant recipients immediately post-transplant and serially thereafter, and in heart transplant recipients. All normal human subjects examined expressed cytokeratin 5 in their buffy coat in amounts that were not significantly influenced by age or gender. There was a profound, statistically significant decrease in cytokeratin 5 mRNA expression levels in lung transplant patients compared to healthy human subjects (p = 3.1x10(-13)) and to heart transplant recipients. There was a moderate negative correlation between improved circulating cytokeratin 5 mRNA levels in lung transplant recipients with recovering lung function, as measured by improved FEV1 values (rho = -0.39).Levels of cytokeratin 5 mRNA, a proxy marker for circulating epithelial progenitor cells, inversely correlated with disease status in lung transplant recipients. It may therefore serve as a biomarker of the clinical outcome of lung transplant patients and potentially other patients with airway injury

Gene Expression Profiling of Bronchoalveolar Lavage Cells Preceding a Clinical Diagnosis of Chronic Lung Allograft Dysfunction.

BackgroundChronic Lung Allograft Dysfunction (CLAD) is the main limitation to long-term survival after lung transplantation. Although CLAD is usually not responsive to treatment, earlier identification may improve treatment prospects.MethodsIn a nested case control study, 1-year post transplant surveillance bronchoalveolar lavage (BAL) fluid samples were obtained from incipient CLAD (n = 9) and CLAD free (n = 8) lung transplant recipients. Incipient CLAD cases were diagnosed with CLAD within 2 years, while controls were free from CLAD for at least 4 years following bronchoscopy. Transcription profiles in the BAL cell pellets were assayed with the HG-U133 Plus 2.0 microarray (Affymetrix). Differential gene expression analysis, based on an absolute fold change (incipient CLAD vs no CLAD) >2.0 and an unadjusted p-value ≤0.05, generated a candidate list containing 55 differentially expressed probe sets (51 up-regulated, 4 down-regulated).ResultsThe cell pellets in incipient CLAD cases were skewed toward immune response pathways, dominated by genes related to recruitment, retention, activation and proliferation of cytotoxic lymphocytes (CD8+ T-cells and natural killer cells). Both hierarchical clustering and a supervised machine learning tool were able to correctly categorize most samples (82.3% and 94.1% respectively) into incipient CLAD and CLAD-free categories.ConclusionsThese findings suggest that a pathobiology, similar to AR, precedes a clinical diagnosis of CLAD. A larger prospective investigation of the BAL cell pellet transcriptome as a biomarker for CLAD risk stratification is warranted

Safety and tolerability of nintedanib in patients with progressive fibrosing interstitial lung diseases: data from the randomized controlled INBUILD trial

Background: In the INBUILD trial in patients with progressive fibrosing interstitial lung diseases (ILDs), nintedanib reduced the rate of decline in forced vital capacity compared with placebo, with side-effects that were manageable for most patients. We used data from the INBUILD trial to characterize further the safety and tolerability of nintedanib. Methods: Patients with fibrosing ILDs other than idiopathic pulmonary fibrosis (IPF), who had experienced progression of ILD within the 24 months before screening despite management deemed appropriate in clinical practice, were randomized to receive nintedanib 150 mg twice daily or placebo. To manage adverse events, treatment could be interrupted or the dose reduced to 100 mg twice daily. We assessed adverse events and dose adjustments over the whole trial. Results: A total of 332 patients received nintedanib and 331 received placebo. Median exposure to trial drug was 17.4 months in both treatment groups. Adverse events led to treatment discontinuation in 22.0% of patients treated with nintedanib and 14.5% of patients who received placebo. The most frequent adverse event was diarrhea, reported in 72.3% of patients in the nintedanib group and 25.7% of patients in the placebo group. Diarrhea led to treatment discontinuation in 6.3% of patients in the nintedanib group and 0.3% of the placebo group. In the nintedanib and placebo groups, respectively, 48.2% and 15.7% of patients had >= 1 dose reduction and/or treatment interruption. Serious adverse events were reported in 44.3% of patients in the nintedanib group and 49.5% of patients in the placebo group. The adverse event profile of nintedanib was generally consistent across subgroups based on age, sex, race and weight, but nausea, vomiting and dose reductions were more common among female than male patients. Conclusions: The adverse event profile of nintedanib in patients with progressive fibrosing ILDs other than IPF is consistent with its established safety and tolerability profile in patients with IPF and characterized mainly by gastrointestinal events, particularly diarrhea. Management of adverse events using symptomatic therapies and dose adjustment is important to minimize the impact of adverse events and help patients remain on therapy

Expression of chemokines and their receptors by human brain endothelium: Implications for multiple sclerosis

Leukocyte migration into the CNS is mediated by chemokines, expressed on the surface of brain endothelium. This study investigated the production of chemokines and expression of chemokine receptors by human brain endothelial cells (HBEC), in vitro and in situ in multiple sclerosis tissue. Four chemokines (CCL2, CCL5, CXCL8 and CXCL10), were demonstrated in endothelial cells in situ, which was reflected in the chemokine production by primary HBEC and a brain endothelial cell line, hCEMC/D3. CXCL8 and CCL2 were constitutively released and increased in response to TNF and/or IFN . CXCL10 and CCL5 were undetectable in resting cells but were secreted in response to these cytokines. TNF strongly increased the production of CCL2, CCL5 and CXCL8, while IFN up-regulated CXCL10 exclusively. CCL3 was not secreted by HBECs and appeared to be confined to astrocytes in situ. The chemokine receptors CXCR1 and CXCR3 were expressed by HBEC both in vitro and in situ, and CXCR3 was up-regulated in response to cytokine stimulation in vitro. By contrast, CXCR3 expression was reduced in silent MS lesions. Brain endothelium expresses particularly high levels of CXCL10 and CXCL8, which may account for the predominant TH1-type inflammatory reaction seen in chronic conditions such as multiple sclerosis

Protection against Bronchiolitis Obliterans Syndrome Is Associated with Allograft CCR7+CD45RA− T Regulatory Cells

Bronchiolitis obliterans syndrome (BOS) is the major obstacle to long-term survival after lung transplantation, yet markers for early detection and intervention are currently lacking. Given the role of regulatory T cells (Treg) in modulation of immunity, we hypothesized that frequencies of Treg in bronchoalveolar lavage fluid (BALF) after lung transplantation would predict subsequent development of BOS. Seventy BALF specimens obtained from 47 lung transplant recipients were analyzed for Treg lymphocyte subsets by flow cytometry, in parallel with ELISA measurements of chemokines. Allograft biopsy tissue was stained for chemokines of interest. Treg were essentially all CD45RA−, and total Treg frequency did not correlate to BOS outcome. The majority of Treg were CCR4+ and CD103− and neither of these subsets correlated to risk for BOS. In contrast, higher percentages of CCR7+ Treg correlated to reduced risk of BOS. Additionally, the CCR7 ligand CCL21 correlated with CCR7+ Treg frequency and inversely with BOS. Higher frequencies of CCR7+ CD3+CD4+CD25hiFoxp3+CD45RA− lymphocytes in lung allografts is associated with protection against subsequent development of BOS, suggesting that this subset of putative Treg may down-modulate alloimmunity. CCL21 may be pivotal for the recruitment of this distinct subset to the lung allograft and thereby decrease the risk for chronic rejection