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

Effects of Plasma HIV RNA, CD4+ T Lymphocytes, and the Chemokine Receptors CCR5 and CCR2b on HIV Disease Progression in Hemophiliacs

We have investigated the effects of plasma HIV RNA, CD4+ T lymphocytes and chemokine receptors CCR5 and CCR2b on HIV disease progression in hemophiliacs. We prospectively observed during follow-up 207 HIV-infected hemophiliacs in the Hemophilia Growth and Development Study. Plasma HIV RNA was measured on cryopreserved plasma from enrollment using the Chiron Corporation bDNA (version 2.0) assay. Genotype variants CCR2b-641 and CCR5-Δ32 were detected using standard molecular techniques. Those with the mutant allele for CCR2b, and to a lesser extent CCR5, had lower plasma HIV RNA, and higher CD4+ T lymphocytes than did those without these genetic variants. After controlling for the effects of plasma HIV RNA and CD4+ T lymphocytes, those with the CCR2b mutant allele compared with those wild-type, had a trend toward a lower risk of progression to AIDS, adjusted relative hazard of 1.94 (95% confidence interval [CI], 0.9-4.18; p = .092), and AIDS-related death, relative hazard 1.97 (95% CI, 0.98-4.00; p = .059). We conclude that plasma HIV RNA, CD4+ T lymphocytes, and CCR genotypes are correlated, and the protective affect of CCR2b against HIV disease progression is not completely explained by plasma HIV RNA or CD4+ T-lymphocyte number

Evaluation of Viremia Frequencies of a Novel Human Pegivirus by Using Bioinformatic Screening and PCR

Next-generation sequencing has critical applications in virus discovery, diagnostics, and environmental surveillance. We used metagenomic sequence libraries for retrospective screening of plasma samples for the recently discovered human hepegivirus 1 (HHpgV-1). From a cohort of 150 hepatitis C virus (HCV)-positive case-patients, we identified 2 persons with HHpgV-1 viremia and a high frequency of human pegivirus (HPgV) viremia (14%). Detection of HHpgV-1 and HPgV was concordant with parallel PCR-based screening using conserved primers matching groups 1 (HPgV) and 2 (HHPgV-1) nonstructural 3 region sequences. PCR identified 1 HHPgV-1-positive person with viremia from a group of 195 persons with hemophilia who had been exposed to nonvirally inactivated factor VII/IX; 18 (9%) were HPgV-positive. Relative to HCV and HPgV, active infections with HHpgV-1 were infrequently detected in blood, even in groups that had substantial parenteral exposure. Our findings are consistent with lower transmissibility or higher rates of virus clearance for HHpgV-1 than for other bloodborne human flaviviruses

The Role of Fibrocytes in Sickle Cell Lung Disease

<div><h3>Background</h3><p>Interstitial lung disease is a frequent complication in sickle cell disease and is characterized by vascular remodeling and interstitial fibrosis. Bone marrow-derived fibrocytes have been shown to contribute to the pathogenesis of other interstitial lung diseases. The goal of this study was to define the contribution of fibrocytes to the pathogenesis of sickle cell lung disease.</p> <h3>Methodology/Principal Findings</h3><p>Fibrocytes were quantified and characterized in subjects with sickle cell disease or healthy controls, and in a model of sickle cell disease, the NY1DD mouse. The role of the chemokine ligand CXCL12 in trafficking of fibrocytes and phenotype of lung disease was examined in the animal model. We found elevated concentration of activated fibrocytes in the peripheral blood of subjects with sickle cell disease, which increased further during vaso-occlusive crises. There was a similar elevations in the numbers and activation phenotype of fibrocytes in the bone marrow, blood, and lungs of the NY1DD mouse, both at baseline and under conditions of hypoxia/re-oxygenation. In both subjects with sickle cell disease and the mouse model, fibrocytes expressed a hierarchy of chemokine receptors, with CXCR4 expressed on most fibrocytes, and CCR2 and CCR7 expressed on a smaller subset of cells. Depletion of the CXCR4 ligand, CXCL12, in the mouse model resulted in a marked reduction of fibrocyte trafficking into the lungs, reduced lung collagen content and improved lung compliance and histology.</p> <h3>Conclusions</h3><p>These data support the notion that activated fibrocytes play a significant role in the pathogenesis of sickle cell lung disease.</p> </div

Genetic Variants in Nuclear-Encoded Mitochondrial Genes Influence AIDS Progression

Background: The human mitochondrial genome includes only 13 coding genes while nuclear-encoded genes account for 99% of proteins responsible for mitochondrial morphology, redox regulation, and energetics. Mitochondrial pathogenesis occurs in HIV patients and genetically, mitochondrial DNA haplogroups with presumed functional differences have been associated with differential AIDS progression. Methodology/Principal Findings: Here we explore whether single nucleotide polymorphisms (SNPs) within 904 of the estimated 1,500 genes that specify nuclear-encoded mitochondrial proteins (NEMPs) influence AIDS progression among HIV-1 infected patients. We examined NEMPs for association with the rate of AIDS progression using genotypes generated by an Affymetrix 6.0 genotyping array of 1,455 European American patients from five US AIDS cohorts. Successfully genotyped SNPs gave 50% or better haplotype coverage for 679 of known NEMP genes. With a Bonferroni adjustment for the number of genes and tests examined, multiple SNPs within two NEMP genes showed significant association with AIDS progression: acyl-CoA synthetase medium-chain family member 4 (ACSM4) on chromosome 12 and peroxisomal D3,D2-enoyl- CoA isomerase (PECI) on chromosome 6. Conclusions: Our previous studies on mitochondrial DNA showed that European haplogroups with presumed functional differences were associated with AIDS progression and HAART mediated adverse events. The modest influences of nuclearencoded mitochondrial genes found in the current study add support to the idea that mitochondrial function plays a role in AIDS pathogenesis

From theory to practice: Applying current clinical knowledge and treatment strategies to the care of hemophilia A patients with inhibitors

Two bypassing agents are currently available to circumvent the need for factor FVIII in hemophilia A patients with inhibitors: the activated prothrombin complex FEIBA VH and recombinant activated factor VII (NovoSeven (R)). Both products are highly effective in controlling bleeding in the presence of inhibitory alloantibodies, yet their hemostatic efficacy can be unpredictable. As the results of the FEIBA NovoSeven (R) Comparative (FENOC) study illustrate, patients may respond better to one bypassing agent than the other. Furthermore, guidelines from an expert panel reflect that responsiveness to bypassing therapy may change from one bleed to the next in the same patient and even from hour to hour during the course of a single bleeding event. These findings underscore the need to have both bypassing products available to treat bleeding episodes in inhibitor patients, to frequently evaluate the efficacy of hemostasis during the course of a bleeding event, and to switch products early if the response to treatment is unsatisfactory. (C) 2008 Elsevier Ltd. All rights reserved

The next generation of hemophilia treatment specialists

We currently are witnessing a serious attrition of physicians specializing in hemophilia treatment in Europe and the United States while most physicians who complete training in hematology-oncology choose oncology practice as their career. Nevertheless, recent therapeutic developments, including advances in prophylaxis and inhibitor management, have renewed the demand for experts in hemophilia and related disorders. To meet this demand, several specialty training programs have been developed in the United States and Europe, specifically the International Course in Hemophilia in Malmo, Sweden, the Children's Hospital of Los Angeles International Pediatric Hemostasis and Thrombosis Program, and the Baxter/National Hemophilia Foundation Fellowship Programs. The purpose of these programs is to enhance the clinical expertise and further the professional development of individuals dedicated to treating patients with coagulation disorders