Jessica Kubo

Genetic and Environmental Determinants of Human NK Cell Diversity Revealed by Mass Cytometry

Both genetics and environment contribute to human NK cell diversity. NK Cell Nature Versus Nurture Natural killer (NK) cells were first discovered because of their ability to kill tumor cells without any previous exposure. However, this population is actually quite heterogeneous: Different subgroups of NK cells express different combinations of activating and inhibiting receptors that govern their specificity. Now, Horowitz et al. use mass cytometry to examine NK cell diversity in humans. The authors examined 35 parameters simultaneously in 5 sets of monozygotic twins as well as 12 unrelated donors. They found up to 30,000 phenotypic NK cell populations in a given individual. What’s more, by comparing the twins versus unrelated donors, they determined that although genetics primarily determined inhibitory receptor expression, activating receptors were controlled by the environment. These data suggest that inhibitory receptors may contribute more to NK cell self-tolerance, whereas activating receptors may guide response to pathogens and tumors. Natural killer (NK) cells play critical roles in immune defense and reproduction, yet remain the most poorly understood major lymphocyte population. Because their activation is controlled by a variety of combinatorially expressed activating and inhibitory receptors, NK cell diversity and function are closely linked. To provide an unprecedented understanding of NK cell repertoire diversity, we used mass cytometry to simultaneously analyze 37 parameters, including 28 NK cell receptors, on peripheral blood NK cells from 5 sets of monozygotic twins and 12 unrelated donors of defined human leukocyte antigen (HLA) and killer cell immunoglobulin-like receptor (KIR) genotype. This analysis revealed a remarkable degree of NK cell diversity, with an estimated 6000 to 30,000 phenotypic populations within an individual and >100,000 phenotypes in the donor panel. Genetics largely determined inhibitory receptor expression, whereas activation receptor expression was heavily environmentally influenced. Therefore, NK cells may maintain self-tolerance through strictly regulated expression of inhibitory receptors while using adaptable expression patterns of activating and costimulatory receptors to respond to pathogens and tumors. These findings further suggest the possibility that discrete NK cell subpopulations could be harnessed for immunotherapeutic strategies in the settings of infection, reproduction, and transplantation.

Blocking the NOTCH Pathway Inhibits Vascular Inflammation in Large-Vessel Vasculitis

Background— Giant cell arteritis is a granulomatous vasculitis of the aorta and its branches that causes blindness, stroke, and aortic aneurysm. CD4 T cells are key pathogenic regulators, instructed by vessel wall dendritic cells to differentiate into vasculitic T cells. The unique pathways driving this dendritic cell–T-cell interaction are incompletely understood, but may provide novel therapeutic targets for a disease in which the only established therapy is long-term treatment with high doses of corticosteroids. Methods and Results— Immunohistochemical and gene expression analyses of giant cell arteritis-affected temporal arteries revealed abundant expression of the NOTCH receptor and its ligands, Jagged1 and Delta1. Cleavage of the NOTCH intracellular domain in wall-infiltrating T cells indicated ongoing NOTCH pathway activation in large-vessel vasculitis. NOTCH activation did not occur in small-vessel vasculitis affecting branches of the vasa vasorum tree. We devised 2 strategies to block NOTCH pathway activation: &ggr;-secretase inhibitor treatment, preventing nuclear translocation of the NOTCH intracellular domain, and competing for receptor-ligand interactions through excess soluble ligand, Jagged1-Fc. In a humanized mouse model, NOTCH pathway disruption had strong immunosuppressive effects, inhibiting T-cell activation in the early and established phases of vascular inflammation. NOTCH inhibition was particularly effective in downregulating Th17 responses, but also markedly suppressed Th1 responses. Conclusions— Blocking NOTCH signaling depleted T cells from the vascular infiltrates, implicating NOTCH- NOTCH ligand interactions in regulating T-cell retention and survival in vessel wall inflammation. Modulating the NOTCH signaling cascade emerges as a promising new strategy for immunosuppressive therapy of large-vessel vasculitis.

Influence of donor and recipient sex mismatch on heart transplant outcomes: Analysis of the International Society for Heart and Lung Transplantation Registry

BACKGROUND Prior studies have presented contradictory results after analyzing associations between donor and recipient sex on survival after heart transplantation and causes of death such as acute rejection (AR) and cardiac allograft vasculopathy (CAV). We used the International Society for Heart and Lung Transplantation (ISHLT) Registry, the largest repository of heart transplant outcomes worldwide, to comprehensively address these questions. METHOD We studied 60,584 adult recipients of heart transplants performed between 1990 and 2008. Outcomes of interest were overall survival, death-censored allograft survival, AR, and CAV, which were studied using regression models. To assess whether donor/recipient sex mismatch affected outcomes, the experience of male recipients with female vs male donors was compared with that of female recipients with female vs male donors through inclusion of an interaction term between donor and recipient sex. RESULTS Significant differences were observed between male and female recipients in overall survival and death-censored allograft survival for female vs male donors. Male recipients of female allografts had a 10% increase in adjusted mortality relative to male recipients of male allografts, whereas female recipients of female allografts had a 10% decrease in adjusted mortality relative to female recipients of male allografts (p < 0.0001). Findings were similar for death-censored allograft survival. Differences in the effect of donor sex on AR or CAV between male and female recipients were not significant. CONCLUSIONS Analysis of the ISHLT data set has demonstrated a strong association between donor/recipient sex mismatch and reduced survival after heart transplantation.

Aspirin is associated with lower melanoma risk among postmenopausal Caucasian women: the Women's Health Initiative.

Nonsteroidal anti‐inflammatory drugs (NSAIDs) have been associated with decreased risk of gastric, colorectal, and breast cancer. However, the impact of NSAIDs on the risk of melanoma has been inconsistent. The authors evaluated the association between NSAID use and cutaneous melanoma risk in the Womens Health Initiative (WHI) Observational Study (OS).

Contribution of health status and prevalent chronic disease to individual risk for workplace injury in the manufacturing environment

Objectives An ‘information gap’ has been identified regarding the effects of chronic disease on occupational injury risk. We investigated the association of ischaemic heart disease, hypertension, diabetes, depression and asthma with acute occupational injury in a cohort of manufacturing workers from 1 January 1997 through 31 December 2007. Methods We used administrative data on real-time injury, medical claims, workplace characteristics and demographics to examine this association. We employed a piecewise exponential model within an Andersen–Gill framework with a frailty term at the employee level to account for inclusion of multiple injuries for each employee, random effects at the employee level due to correlation among jobs held by an employee, and experience on the job as a covariate. Results One-third of employees had at least one of the diseases during the study period. After adjusting for potential confounders, presence of these diseases was associated with increased hazard of injury: heart disease (HR 1.23, 95% CI 1.11 to 1.36), diabetes (HR 1.17, 95% CI 1.08 to 1.27), depression (HR 1.25, 95% CI 1.12 to 1.38) and asthma (HR 1.14, 95% CI 1.02 to 1.287). Hypertension was not significantly associated with hazard of injury. Associations of chronic disease with injury risk were less evident for more serious reportable injuries; only depression and a summary health metric derived from claims remained significantly positive in this subset. Conclusions Our results suggest that chronic heart disease, diabetes and depression confer an increased risk for acute occupational injury.

Randomized clinical trial to evaluate the efficacy and safety of valganciclovir in a subset of patients with chronic fatigue syndrome

There is no known treatment for chronic fatigue syndrome (CFS). Little is known about its pathogenesis. Human herpesvirus 6 (HHV‐6) and Epstein–Barr virus (EBV) have been proposed as infectious triggers. Thirty CFS patients with elevated IgG antibody titers against HHV‐6 and EBV were randomized 2:1 to receive valganciclovir (VGCV) or placebo for 6 months in a double‐blind, placebo‐controlled trial. Clinical endpoints aimed at measuring physical and mental fatigue included the Multidimensional Fatigue Inventory (MFI‐20) and Fatigue Severity Scale (FSS) scores, self‐reported cognitive function, and physician‐determined responder status. Biological endpoints included monocyte and neutrophil counts and cytokine levels. VGCV patients experienced a greater improvement by MFI‐20 at 9 months from baseline compared to placebo patients but this difference was not statistically significant. However, statistically significant differences in trajectories between groups were observed in MFI‐20 mental fatigue subscore (P = 0.039), FSS score (P = 0.006), and cognitive function (P = 0.025). VGCV patients experienced these improvements within the first 3 months and maintained that benefit over the remaining 9 months. Patients in the VGCV arm were 7.4 times more likely to be classified as responders (P = 0.029). In the VGCV arm, monocyte counts decreased (P < 0.001), neutrophil counts increased (P = 0.037) and cytokines were more likely to evolve towards a Th1‐profile (P < 0.001). Viral IgG antibody titers did not differ between arms. VGCV may have clinical benefit in a subset of CFS patients independent of placebo effect, possibly mediated by immunomodulation and/or antiviral effect. Further investigation with longer treatment duration and a larger sample size is warranted. J. Med. Virol. 85:2101–2109, 2013.

Lower skin cancer risk in women with higher body mass index: The Women's Health Initiative Observational Study

The unclear relationship of obesity to incident melanoma and nonmelanoma skin cancer (NMSC) risks was evaluated in the large, geographically diverse longitudinal, prospective Womens Health Initiative (WHI) observational study. Risks of melanoma and NMSC in normal weight women were compared with risks in overweight [body mass index (BMI) = 25–29.0 kg/m2] and obese (BMI ≥ 30 kg/m2) women, using Cox proportional hazards models for melanoma and logistic regression for NMSC. Over a mean 9.4 years of follow-up, there were 386 melanoma and 9,870 NSMC cases. Risk of melanoma did not differ across weight categories (P = 0.86), whereas in fully adjusted models, NMSC risk was lower in overweight [OR, 0.93; 95% confidence interval (CI), 0.89–0.99] and obese (OR, 0.85; 95% CI, 0.80–0.91) women (P < 0.001). Excess body weight was not associated with melanoma risk in postmenopausal women but was inversely associated with NMSC risk, possibly due to lower sun exposure in overweight and obese women. This supports previous work demonstrating the relationship between excess body weight and skin cancer risk. Cancer Epidemiol Biomarkers Prev; 22(12); 2412–5. ©2013 AACR.

Neighborhood socioeconomic change and diabetes risk: Findings from the Chicago childhood diabetes registry

OBJECTIVE To examine whether patterns in socioeconomic characteristics in Chicago over a 30-year period are associated with neighborhood distribution of youth diabetes risk. RESEARCH DESIGN AND METHODS Incident cases of diabetes in youth aged 0–17 years were identified from the Chicago Childhood Diabetes Registry between 1994 and 2003. Those with a type 2 diabetes–like clinical course or related indicators were classified as non–type 1 diabetic; the remaining cases were considered to have type 1 diabetes. RESULTS Compared with stable diversity neighborhoods, significant associations for type 1 diabetes were found for younger children residing in emerging low-income neighborhoods (relative risk 0.56 [95% CI 0.36–0.90]) and older children residing in emerging high-income neighborhoods (1.52 [1.17–1.98]). For non–type 1 diabetes, older youth residing in desertification neighborhoods were at increased risk (1.47 [1.09–1.99]). CONCLUSIONS Neighborhood socioeconomic characteristics in Chicago may be associated with the risk of diabetes in youth.

The Handling of Missing Data in Molecular Epidemiology Studies

Molecular epidemiology studies face a missing data problem, as biospecimen or imaging data are often collected on only a proportion of subjects eligible for study. We investigated all molecular epidemiology studies published as Research Articles, Short Communications, or Null Results in Brief in Cancer Epidemiology, Biomarkers & Prevention from January 1, 2009, to March 31, 2010, to characterize the extent that missing data were present and to elucidate how the issue was addressed. Of 278 molecular epidemiology studies assessed, most (95%) had missing data on a key variable (66%) and/or used availability of data (often, but not always the biomarker data) as inclusion criterion for study entry (45%). Despite this, only 10% compared subjects included in the analysis with those excluded from the analysis and 88% with missing data conducted a complete-case analysis, a method known to yield biased and inefficient estimates when the data are not missing completely at random. Our findings provide evidence that missing data methods are underutilized in molecular epidemiology studies, which may deleteriously affect the interpretation of results. We provide practical guidelines for the analysis and interpretation of molecular epidemiology studies with missing data. Cancer Epidemiol Biomarkers Prev; 20(8); 1571–9. ©2011 AACR.

Active and passive smoking in relation to lung cancer incidence in the Women's Health Initiative Observational Study prospective cohort

BACKGROUND Lung cancer is the leading cause of worldwide cancer deaths. While smoking is its leading risk factor, few prospective cohort studies have reported on the association of lung cancer with both active and passive smoking. This study aimed to determine the relationship between lung cancer incidence with both active and passive smoking (childhood, adult at home, and at work). PATIENTS AND METHODS The Womens Health Initiative Observational Study (WHI-OS) was a prospective cohort study conducted at 40 US centers that enrolled postmenopausal women from 1993 to 1999. Among 93 676 multiethnic participants aged 50-79, 76 304 women with complete smoking and covariate data comprised the analytic cohort. Lung cancer incidence was calculated by Cox proportional hazards models, stratified by smoking status. RESULTS Over 10.5 mean follow-up years, 901 lung cancer cases were identified. Compared with never smokers (NS), lung cancer incidence was much higher in current [hazard ratio (HR) 13.44, 95% confidence interval (CI) 10.80-16.75] and former smokers (FS; HR 4.20, 95% CI 3.48-5.08) in a dose-dependent manner. Current and FS had significantly increased risk for all lung cancer subtypes, particularly small-cell and squamous cell carcinoma. Among NS, any passive smoking exposure did not significantly increase lung cancer risk (HR 0.88, 95% CI 0.52-1.49). However, risk tended to be increased in NS with adult home passive smoking exposure ≥30 years, compared with NS with no adult home exposure (HR 1.61, 95% CI 1.00-2.58). CONCLUSIONS In this prospective cohort of postmenopausal women, active smoking significantly increased risk of all lung cancer subtypes; current smokers had significantly increased risk compared with FS. Among NS, prolonged passive adult home exposure tended to increase lung cancer risk. These data support continued need for smoking prevention and cessation interventions, passive smoking research, and further study of lung cancer risk factors in addition to smoking. CLINICALTRIALS.GOV: NCT00000611.BACKGROUND Lung cancer is the leading cause of worldwide cancer deaths. While smoking is its leading risk factor, few prospective cohort studies have reported on the association of lung cancer with both active and passive smoking. This study aimed to determine the relationship between lung cancer incidence with both active and passive smoking (childhood, adult at home, and at work). PATIENTS AND METHODS The Womens Health Initiative Observational Study (WHI-OS) was a prospective cohort study conducted at 40 US centers that enrolled postmenopausal women from 1993 to 1999. Among 93 676 multiethnic participants aged 50-79, 76 304 women with complete smoking and covariate data comprised the analytic cohort. Lung cancer incidence was calculated by Cox proportional hazards models, stratified by smoking status. RESULTS Over 10.5 mean follow-up years, 901 lung cancer cases were identified. Compared with never smokers (NS), lung cancer incidence was much higher in current [hazard ratio (HR) 13.44, 95% confidence interval (CI) 10.80-16.75] and former smokers (FS; HR 4.20, 95% CI 3.48-5.08) in a dose-dependent manner. Current and FS had significantly increased risk for all lung cancer subtypes, particularly small-cell and squamous cell carcinoma. Among NS, any passive smoking exposure did not significantly increase lung cancer risk (HR 0.88, 95% CI 0.52-1.49). However, risk tended to be increased in NS with adult home passive smoking exposure ≥30 years, compared with NS with no adult home exposure (HR 1.61, 95% CI 1.00-2.58). CONCLUSIONS In this prospective cohort of postmenopausal women, active smoking significantly increased risk of all lung cancer subtypes; current smokers had significantly increased risk compared with FS. Among NS, prolonged passive adult home exposure tended to increase lung cancer risk. These data support continued need for smoking prevention and cessation interventions, passive smoking research, and further study of lung cancer risk factors in addition to smoking. CLINICALTRIALS.GOV: NCT00000611.