Analysis of somatic mutations in whole blood from 200,618 individuals identifies pervasive positive selection and novel drivers of clonal hematopoiesis.

Human aging is marked by the emergence of a tapestry of clonal expansions in dividing tissues, particularly evident in blood as clonal hematopoiesis (CH). CH, linked to cancer risk and aging-related phenotypes, often stems from somatic mutations in a set of established genes. However, the majority of clones lack known drivers. Here we infer gene-level positive selection in whole blood exomes from 200,618 individuals in UK Biobank. We identify 17 additional genes, ZBTB33, ZNF318, ZNF234, SPRED2, SH2B3, SRCAP, SIK3, SRSF1, CHEK2, CCDC115, CCL22, BAX, YLPM1, MYD88, MTA2, MAGEC3 and IGLL5, under positive selection at a population level, and validate this selection pattern in 10,837 whole genomes from single-cell-derived hematopoietic colonies. Clones with mutations in these genes grow in frequency and size with age, comparable to classical CH drivers. They correlate with heightened risk of infection, death and hematological malignancy, highlighting the significance of these additional genes in the aging process.

An immune-based tool platform for in vivo cell clearance.

Immunological targeting of pathological cells has been successful in oncology and is expanding to other pathobiological contexts. Here, we present a flexible platform that allows labeling cells of interest with the surface-expressed model antigen ovalbumin (OVA), which can be eliminated via either antigen-specific T cells or newly developed OVA antibodies. We demonstrate that hepatocytes can be effectively targeted by either modality. In contrast, pro-fibrotic fibroblasts associated with pulmonary fibrosis are only eliminated by T cells in initial experiments, which reduced collagen deposition in a fibrosis model. This new experimental platform will facilitate development of immune-based approaches to clear potential pathological cell types in vivo.

Analysis of MRI-derived spleen iron in the UK Biobank identifies genetic variation linked to iron homeostasis and hemolysis.

The spleen plays a key role in iron homeostasis. It is the largest filter of the blood and performs iron reuptake from old or damaged erythrocytes. Despite this role, spleen iron concentration has not been measured in a large, population-based cohort. In this study, we quantify spleen iron in 41,764 participants of the UK Biobank by using magnetic resonance imaging and provide a reference range for spleen iron in an unselected population. Through genome-wide association study, we identify associations between spleen iron and regulatory variation at two hereditary spherocytosis genes, ANK1 and SPTA1. Spherocytosis-causing coding mutations in these genes are associated with lower reticulocyte volume and increased reticulocyte percentage, while these common alleles are associated with increased expression of ANK1 and SPTA1 in blood and with larger reticulocyte volume and reduced reticulocyte percentage. As genetic modifiers, these common alleles may explain mild spherocytosis phenotypes that have been observed clinically. Our genetic study also identifies a signal that co-localizes with a splicing quantitative trait locus for MS4A7, and we show this gene is abundantly expressed in the spleen and in macrophages. The combination of deep learning and efficient image processing enables non-invasive measurement of spleen iron and, in turn, characterization of genetic factors related to the lytic phase of the erythrocyte life cycle and iron reuptake in the spleen.

CD38 inhibitor 78c increases mice lifespan and healthspan in a model of chronological aging.

Nicotinamide adenine dinucleotide (NAD) levels decline during aging, contributing to physical and metabolic dysfunction. The NADase CD38 plays a key role in age-related NAD decline. Whether the inhibition of CD38 increases lifespan is not known. Here, we show that the CD38 inhibitor 78c increases lifespan and healthspan of naturally aged mice. In addition to a 10% increase in median survival, 78c improved exercise performance, endurance, and metabolic function in mice. The effects of 78c were different between sexes. Our study is the first to investigate the effect of CD38 inhibition in naturally aged animals.

Novel insights from a multiomics dissection of the Hayflick limit.

The process wherein dividing cells exhaust proliferative capacity and enter into replicative senescence has become a prominent model for cellular aging in vitro. Despite decades of study, this cellular state is not fully understood in culture and even much less so during aging. Here, we revisit Leonard Hayflick's original observation of replicative senescence in WI-38 human lung fibroblasts equipped with a battery of modern techniques including RNA-seq, single-cell RNA-seq, proteomics, metabolomics, and ATAC-seq. We find evidence that the transition to a senescent state manifests early, increases gradually, and corresponds to a concomitant global increase in DNA accessibility in nucleolar and lamin associated domains. Furthermore, we demonstrate that senescent WI-38 cells acquire a striking resemblance to myofibroblasts in a process similar to the epithelial to mesenchymal transition (EMT) that is regulated by t YAP1/TEAD1 and TGF-ß2. Lastly, we show that verteporfin inhibition of YAP1/TEAD1 activity in aged WI-38 cells robustly attenuates this gene expression program.

Hepatitis B seroprevalence in the U.S. military and its impact on potential screening strategies.

INTRODUCTION: Knowledge of the contemporary epidemiology of hepatitis B virus (HBV) infection among military personnel can inform potential Department of Defense (DoD) screening policy and infection and disease control strategies. MATERIALS AND METHODS: HBV infection status at accession and following deployment was determined by evaluating reposed serum from 10,000 service members recently deployed to combat operations in Iraq and Afghanistan in the period from 2007 to 2010. A cost model was developed from the perspective of the Department of Defense for a program to integrate HBV infection screening of applicants for military service into the existing screening program of screening new accessions for vaccine-preventable infections. RESULTS: The prevalence of chronic HBV infection at accession was 2.3/1,000 (95% CI: 1.4, 3.2); most cases (16/21, 76%) identified after deployment were present at accession. There were 110 military service-related HBV infections identified. Screening accessions who are identified as HBV susceptible with HBV surface antigen followed by HBV surface antigen neutralization for confirmation offered no cost advantage over not screening and resulted in a net annual increase in cost of $5.78 million. However, screening would exclude as many as 514 HBV cases each year from accession. CONCLUSIONS: Screening for HBV infection at service entry would potentially reduce chronic HBV infection in the force, decrease the threat of transfusion-transmitted HBV infection in the battlefield blood supply, and lead to earlier diagnosis and linkage to care; however, applicant screening is not cost saving. Service-related incident infections indicate a durable threat, the need for improved laboratory-based surveillance tools, and mandate review of immunization policy and practice.

Impact of multisectoral health determinants on child mortality 1980-2010: An analysis by country baseline mortality.

INTRODUCTION: Some health determinants require relatively stronger health system capacity and socioeconomic development than others to impact child mortality. Few quantitative analyses have analyzed how the impact of health determinants varies by mortality level. METHODS: 149 low- and middle-income countries were stratified into high, moderate, low, and very low baseline levels of child mortality in 1990. Data for 52 health determinants were collected for these countries for 1980-2010. To quantify how changes in health determinants were associated with mortality decline, univariable and multivariable regression models were constructed. An advanced statistical technique that is new for child mortality analyses-MM-estimation with first differences and country clustering-controlled for outliers, fixed effects, and variation across decades. FINDINGS: Some health determinants (immunizations, education) were consistently associated with child mortality reduction across all mortality levels. Others (staff availability, skilled birth attendance, fertility, water and sanitation) were associated with child mortality reduction mainly in low or very low mortality settings. The findings indicate that the impact of some health determinants on child mortality was only apparent with stronger health systems, public infrastructure and levels of socioeconomic development, whereas the impact of other determinants was apparent at all stages of development. Multisectoral progress was essential to mortality reduction at all baseline mortality levels. CONCLUSION: Policy-makers can use such analyses to direct investments in health and non-health sectors and to set five-year child mortality targets appropriate for their baseline mortality levels and local context.

Communication in Drug Development: "Translating" Scientific Discovery.

The discovery and development of new medicines that promote human health and potentially extend natural life remains a remarkably challenging endeavor. In this Commentary, we identify key elements of communication required to successfully translate promising biological findings to novel approved drug therapies and discuss the attendant challenges and opportunities.

Country progress towards the Millennium Development Goals: adjusting for socioeconomic factors reveals greater progress and new challenges.

BACKGROUND: The health Millennium Development Goals (4, 5, 6) impose the same ambitious 2015 targets on every country. Few low-income countries are on track to reach them. Some authors have proposed country-specific targets as a more informative method by which countries can measure their progress against their potential. METHODS: This paper demonstrates a supplementary approach to assess individual country progress that complements the global goals by adjusting for socioeconomic resources and prior time trends. A minimum performance target adjusts for time and national GDP. Fast-track targets, based on best-performing countries' progress within regional and income groups, adjust for health and non-health sector factors known to affect maternal and child health. RESULTS: Measuring by the minimum performance target, 74% and 59% of low- and middle-income countries are on track for reducing child mortality and maternal mortality, respectively, compared with 69% and 22% using global MDGs. Only 20% and 7% of low- and middle-income countries are on track for the child and maternal mortality fast-track targets. CONCLUSIONS: Supplementary targets in maternal and child health, adjusted for each country's resources and policy performance can help countries know if they are truly underperforming relative to their potential. Adjusted targets can also flag countries that have surpassed their potential, and open opportunities for learning from success. FUNDING: Partnership for Maternal, Newborn & Child Health and the Alliance for Health Policy and Systems Research, as part of the Success Factors Study on reducing maternal and child mortality.

From cancer genomics to precision oncology--tissue's still an issue.

Rapidly evolving genome technology has enabled extensive molecular analysis of limited tumor biopsy material, thereby facilitating the broader implementation of personalized cancer medicine. However, genomics-based patient stratification across diverse tumor types is unlikely to supplant tissue-of-origin considerations in addressing clinical needs, including the development and application of novel "rationally targeted" cancer therapies.

An evaluation of the President's Emergency Plan for AIDS Relief effect on health systems strengthening in sub-Saharan Africa.

BACKGROUND: President's Emergency Plan for AIDS Relief (PEPFAR) has been criticized for its vertical or "stove-piping" structure, with resources targeting a specific disease rather than working to strengthen the underlying health system. This study aimed to evaluate whether PEPFAR activities were associated with system-wide improvements in both proximal and distal indicators of health systems strengthening. METHODS: The World Bank database provided 12 indicators of health systems strengthening that were analyzed for their relationship to PEPFAR. Poisson and linear regression models were used to estimate the time trend. We evaluated the PEPFAR impact on health outcomes by comparing the time trend in each of the above indicators between 2 time periods: from 1995 to 2002 (pre-PEPFAR) and from 2004 to 2010 (during PEPFAR). RESULTS: PEPFAR activities showed strong and statistically significant associations with improvements in proximal indicators of health systems strengthening, those related directly to HIV, specifically life expectancy (P = 0.003) and tuberculosis incidence, prevalence, and mortality (P < 0.0001). There were nonsignificant associations between PEPFAR and improvements in distal indicators of health systems strengthening, namely infant mortality and under 5 child mortality. CONCLUSIONS: The progressive scale-up of PEPFAR-supported activities was associated with consistent improvements in proximal indicators of health systems strengthening. It was also associated with improvements in broader measures of health system strength, most clearly life expectancy. Given the limited number of health measures available for this type of analysis, more data must be collected for other indicators to evaluate the effectiveness of the many multibillion dollar global health initiatives.

Adjuvant trials of targeted agents: the newest battleground in the war on cancer.

Two of the great successes in the many decades-long 'war on cancer' are the emergence of adjuvant chemotherapy regimens with lifesaving potential and the subsequent wave of 'targeted' therapies addressing the unique vulnerabilities of particular tumor types. The first intersection of adjuvant treatment and targeted treatment resulted in a spectacularly positive outcome as the addition of the anti-HER2 humanized monoclonal antibody trastuzumab to the standard adjuvant chemotherapy essentially halved the relapse rate among women with HER2+ tumors. Subsequent studies of adjuvant trastuzumab have confirmed its dramatic efficacy in a variety of chemotherapeutic contexts and have been instructive in elucidating some of the challenges ahead for newer targeted agents. The recent negative experience with bevacizumab in the adjuvant colon cancer setting suggests pitfalls and limitations of the current approach to developing adjuvant regimens. A change in thinking may be required to gain the substantial benefits implied by the trastuzumab experience in the broader context of the targeted treatments. The case for a revitalized industry/academia/government partnership to address these challenges is compelling, with the potential for enormous patient and societal benefit. In order to bring potentially lifesaving benefits of this new generation of cancer drugs to patients more rapidly, changes to our 'war strategy' appear necessary.

Physicians in US Prisons in the Era of Mass Incarceration.

The United States leads the world in creating prisoners, incarcerating one in 100 adults and housing 25% of the world's prisoners. Since the 1976, the US Supreme Court ruling that mandated health care for inmates, doctors have been an integral part of the correctional system. Yet conditions within corrections are not infrequently in direct conflict with optimal patient care, particularly for those suffering from mental illness and addiction. In addition to providing and working to improve clinical care for prisoners, physicians have an opportunity and an obligation to advocate for reform in the system of corrections when it conflicts with patient well-being.

Determination of HER2 gene amplification by fluorescence in situ hybridization and concordance with the clinical trials immunohistochemical assay in women with metastatic breast cancer evaluated for treatment with trastuzumab.

PURPOSE: To evaluate the concordance between HER2 gene amplification, determined by fluorescence in situ hybridization (FISH), and HER2 protein overexpression assessed by an immunohistochemical (IHC) assay. The IHC protocol used was a research assay, known as the Clinical Trial Assay (CTA), developed to select women with metastatic breast cancer (MBC) for three pivotal clinical trials of trastuzumab therapy. METHODS: A direct-labeled, dual-probe FISH assay was used to determine HER2 amplification in 623 fixed breast cancer tissue specimens. These specimens had been stored as paraffin-embedded sections for 25 years. All specimens had been analyzed for HER2 protein expression by the CTA. To assess the reproducibility of FISH results in archived material, we evaluated a separate group of 617 breast cancer tissue specimens at two different laboratories. RESULTS: Informative FISH results were available for 529 (85%) of the 623 specimens. Overall concordance between FISH and IHC results was 82% (95% CI; 7885%). Assay agreement between FISH results and specimens with immunostaining scores of 0, 1+, and 3+ were 97, 93 and 89%, respectively. However, only 24% of specimens with 2+ immunostaining scores had HER2 amplification by FISH; there was assay disagreement in 76% of specimens in this IHC subgroup. Interlaboratory FISH concordance was 92% (95% CI; 8994%), indicating very good assay reproducibility in these archived specimens. CONCLUSION: HER2 status determined by CTA-IHC and FISH are significantly correlated; however, differences between these two assays can a ect patient selection for trastuzumab therapy.

Decrease in tumor apparent permeability-surface area product to a MRI macromolecular contrast medium following angiogenesis inhibition with correlations to cytotoxic drug accumulation.

BACKGROUND: New strategies for cancer therapy include the combination of angiogenesis inhibitors with cytotoxins. However, angiogenesis inhibitors may alter tumor microvessel structure and transendothelial permeability thereby reducing tumoral delivery of cytotoxic agents. The aim of this study was to estimate quantitatively the apparent permeability-surface area product (K(PS)) in tumors to a macromolecular contrast medium (MMCM), to follow changes in K(PS) induced by antibodies to vascular endothelial growth factor (anti-VEGF), and to correlate the findings with tumor accumulation of cisplatin, a highly protein-bound cytotoxin, and 5-fluorouracil (5-FU), a small unbound cytotoxin. METHODS: Dynamic MRI enhanced with a MMCM (albumin-(Gd-DTPA)(30)) was analyzed using a two-compartment tumor tissue model (plasma and interstitial water) to quantitatively estimate K(PS). These estimates of K(PS) were correlated with cytotoxic drug accumulations in the tumors. RESULTS: Anti-VEGF treatment reduced K(PS) to MMCM in tumor tissue from 0.013 mL h(-1) cm(-3) (n = 9) at baseline to 0.003 mL h(-1) cm(-3) (n = 9) 24 h later (p <.05). The K(PS) values correlated significantly (r(2) =.78; p <.0001) with the tumor cisplatin accumulation. No correlation (r(2) =.001; p =.89) was found between K(PS) and tumor accumulation of the substantially smaller 5-FU molecule. CONCLUSIONS: MMCM-enhanced MRI can be used to detect and estimate changes in K(PS) to this contrast agent following a single dose of anti-VEGF antibody. The decline in K(PS) induced by this inhibitor of angiogenesis is associated with reduced tumor concentration of a protein-bound cytotoxin, similar in molecular weight to the contrast agent. MRI assays of microvascular status as performed here may be useful to clinically monitor responses to anti-angiogenesis drugs and to optimize the choice and timing of cytotoxic drug administration.