Growth Rate of Plasmodium falciparum: Analysis of Parasite Growth Data From Malaria Volunteer Infection Studies.

BACKGROUND: Growth rate of malaria parasites in the blood of infected subjects is an important measure of efficacy of drugs and vaccines. METHODS: We used log-linear and sine-wave models to estimate the parasite growth rate of the 3D7 strain of Plasmodium falciparum using data from 177 subjects from 14 induced blood stage malaria (IBSM) studies conducted at QIMR Berghofer. We estimated parasite multiplication rate per 48 hours (PMR48), PMR per life-cycle (PMRLC), and parasite life-cycle duration. We compared these parameters to those from studies conducted elsewhere with infections induced by IBSM (n = 66), sporozoites via mosquito bite (n = 336), or injection (n = 51). RESULTS: The parasite growth rate of 3D7 in QIMR Berghofer studies was 0.75/day (95% confidence interval [CI], .73-.77/day), PMR48 was 31.9 (95% CI, 28.7-35.4), PMRLC was 16.4 (95% CI, 15.1-17.8), and parasite life-cycle was 38.8 hours (95% CI, 38.3-39.2 hours). These parameters were similar to estimates from IBSM studies elsewhere (0.71/day, 95% CI, .67-.75/day; PMR48 26.6, 95% CI, 22.2-31.8) but significantly higher (P < .001) than in sporozoite studies (0.47/day, 95% CI, .43-.50/day; PMR48 8.6, 95% CI, 7.3-10.1). CONCLUSIONS: Parasite growth rates were similar across different IBSM studies and higher than infections induced by sporozoite.

Automatic variable selection for exposure-driven propensity score matching with unmeasured confounders.

Multivariable model building for propensity score modeling approaches is challenging. A common propensity score approach is exposure-driven propensity score matching, where the best model selection strategy is still unclear. In particular, the situation may require variable selection, while it is still unclear if variables included in the propensity score should be associated with the exposure and the outcome, with either the exposure or the outcome, with at least the exposure or with at least the outcome. Unmeasured confounders, complex correlation structures, and non-normal covariate distributions further complicate matters. We consider the performance of different modeling strategies in a simulation design with a complex but realistic structure and effects on a binary outcome. We compare the strategies in terms of bias and variance in estimated marginal exposure effects. Considering the bias in estimated marginal exposure effects, the most reliable results for estimating the propensity score are obtained by selecting variables related to the exposure. On average this results in the least bias and does not greatly increase variances. Although our results cannot be generalized, this provides a counterexample to existing recommendations in the literature based on simple simulation settings. This highlights that recommendations obtained in simple simulation settings cannot always be generalized to more complex, but realistic settings and that more complex simulation studies are needed.

Multidimensional phenotyping of breast cancer cell lines to guide preclinical research.

PURPOSE: Cell lines are extremely useful tools in breast cancer research. Their key benefits include a high degree of control over experimental variables and reproducibility. However, the advantages must be balanced against the limitations of modelling such a complex disease in vitro. Informed selection of cell line(s) for a given experiment now requires essential knowledge about molecular and phenotypic context in the culture dish. METHODS: We performed multidimensional profiling of 36 widely used breast cancer cell lines that were cultured under standardised conditions. Flow cytometry and digital immunohistochemistry were used to compare the expression of 14 classical breast cancer biomarkers related to intrinsic molecular profiles and differentiation states: EpCAM, CD24, CD49f, CD44, ER, AR, HER2, EGFR, E-cadherin, p53, vimentin, and cytokeratins 5, 8/18 and 19. RESULTS: This cell-by-cell analysis revealed striking heterogeneity within cultures of individual lines that would be otherwise obscured by analysing cell homogenates, particularly amongst the triple-negative lines. High levels of p53 protein, but not RNA, were associated with somatic mutations (p = 0.008). We also identified new subgroups using the nanoString PanCancer Pathways panel (730 transcripts representing 13 canonical cancer pathways). Unsupervised clustering identified five groups: luminal/HER2, immortalised ('normal'), claudin-low and two basal clusters, distinguished mostly by baseline expression of TGF-beta and PI3-kinase pathway genes. CONCLUSION: These features are compared with other published genotype and phenotype information in a user-friendly reference table to help guide selection of the most appropriate models for in vitro and in vivo studies, and as a framework for classifying new patient-derived cancer cell lines and xenografts.

Clinically proven drug targets differentially expressed in the prefrontal cortex of schizophrenia patients.

BACKGROUND: Due to the heterogeneous nature of schizophrenia, understanding the genetic risk for the disease is a complex task. Gene expression studies have proven to be more reliable than association studies as they are consistently replicated in a tissue specific manner. METHODS: Using RNA-Seq we analysed gene expression in the frontal cortex of 24 individuals with schizophrenia and 25 unaffected controls. RESULTS: We identified 1146 genes that were differentially expressed in schizophrenia, approximately 60% of which were up-regulated and 366 of 1146 (32%) also have aberrant DNA methylation (p=2.46×10-39). The differentially expressed genes were significantly overrepresented in several pathways including inflammatory (p=8.7×10-3) and nitric oxide pathways (p=9.2×10-4). Moreover, these genes were significantly enriched for those with a druggable genome (p=0.04). We identified a number of genes that are significantly up-regulated in schizophrenia as confirmed in other gene expression studies using different brain tissues. Of the 349 genes associated with schizophrenia from the Psychiatric Genomics Consortium we identified 16 genes that are significant from our list of differentially expressed genes. CONCLUSIONS: Our results identified biological functional genes that are differentially expressed in schizophrenia. A subset of these genes are clinically proven drug targets. We also found a strong pattern of differentially expressed immune response genes that may reflect an underlying defect in schizophrenia.

Serum ferritin concentration predicts hepatic fibrosis better than hepatic iron concentration in human HFE-Haemochromatosis.

BACKGROUND & AIMS: Ferritin is purported to have proinflammatory and profibrogenic effects on hepatic stellate cells. Thus, rather than acting as a passive indicator of hepatic iron concentration (HIC) in haemochromatosis, ferritin may directly influence fibrosis. This study evaluated whether serum ferritin is a better predictor of hepatic fibrosis compared to variables previously associated with increased fibrosis risk in haemochromatosis. METHODS: We identified 291 C282Y HFE-homozygous patients who had undergone liver biopsy for histological fibrosis staging and measurement of HIC. Ordinal logistic regression determined the best model for fibrosis stage not including serum ferritin. Then, serum ferritin was introduced into this model to assess whether the predictive power of the model was significantly increased and to evaluate the effect on other predictors of fibrosis. RESULTS: Ordinal logistic regression analyses without serum ferritin demonstrated that log HIC (OR 2.89; P < .001), male gender (OR 2.93; P = .005), alcohol consumption (g/day) (OR 1.01; P = .004), steatosis (OR 2.86; P = .01), arthritis (OR 2.46; P = .01) predicted increasing fibrosis stage (n=217). Addition of serum ferritin in multivariate analysis substantially improved the predictive power of the model (χ2  = 37.15; P < .01) and was highly predictive of fibrosis stage (OR 5.44; P < .001). Inclusion of serum ferritin in this model rendered the effects of HIC, gender, alcohol and steatosis to non-significance. CONCLUSIONS: In haemochromatosis, serum ferritin is a better predictor of fibrosis stage than HIC, gender, steatosis and alcohol. These data support a hypothesis that ferritin may play a role in fibrosis rather than simply acting as a passive indicator of iron storage.

Comparison of statistical models to estimate parasite growth rate in the induced blood stage malaria model.

BACKGROUND: The efficacy of vaccines aimed at inhibiting the growth of malaria parasites in the blood can be assessed by comparing the growth rate of parasitaemia in the blood of subjects treated with a test vaccine compared to controls. In studies using induced blood stage malaria (IBSM), a type of controlled human malaria infection, parasite growth rate has been measured using models with the intercept on the y-axis fixed to the inoculum size. A set of statistical models was evaluated to determine an optimal methodology to estimate parasite growth rate in IBSM studies. METHODS: Parasite growth rates were estimated using data from 40 subjects published in three IBSM studies. Data was fitted using 12 statistical models: log-linear, sine-wave with the period either fixed to 48 h or not fixed; these models were fitted with the intercept either fixed to the inoculum size or not fixed. All models were fitted by individual, and overall by study using a mixed effects model with a random effect for the individual. RESULTS: Log-linear models and sine-wave models, with the period fixed or not fixed, resulted in similar parasite growth rate estimates (within 0.05 log10 parasites per mL/day). Average parasite growth rate estimates for models fitted by individual with the intercept fixed to the inoculum size were substantially lower by an average of 0.17 log10 parasites per mL/day (range 0.06-0.24) compared with non-fixed intercept models. Variability of parasite growth rate estimates across the three studies analysed was substantially higher (3.5 times) for fixed-intercept models compared with non-fixed intercept models. The same tendency was observed in models fitted overall by study. Modelling data by individual or overall by study had minimal effect on parasite growth estimates. CONCLUSIONS: The analyses presented in this report confirm that fixing the intercept to the inoculum size influences parasite growth estimates. The most appropriate statistical model to estimate the growth rate of blood-stage parasites in IBSM studies appears to be a log-linear model fitted by individual and with the intercept estimated in the log-linear regression. Future studies should use this model to estimate parasite growth rates.

High content screening application for cell-type specific behaviour in heterogeneous primary breast epithelial subpopulations.

BACKGROUND: The complex interaction between multiple cell types and the microenvironment underlies the diverse pathways to carcinogenesis and necessitates sophisticated approaches to in vitro hypotheses testing. The combination of mixed culture format with high content immunofluorescence screening technology provides a powerful platform for observation of cell type specific behavior. METHODS: We have developed a versatile, high-throughput method for assessing cell-type specific responses. In addition to the specificity and sensitivity offered traditionally by immunofluorescent detection in flow cytometry, the 'in-cell' analysis method we describe provides the added benefits of higher throughput and the ability to analyse protein subcellular localisation in situ. Furthermore, elimination of the cell dissociation step allows for more immediate analysis of responses to specific extrinsic stimuli. We applied this method to investigate ionising radiation treatment response in normal breast epithelial cells, measuring growth rate, cell cycle response and double-strand DNA breaks. RESULTS: The 'in-cell' analysis approach elucidated several interesting donor and cell-type specific differences. Notably, in response to ionizing radiation we observed differential expression in luminal and basal-like cells of a member of the APOBEC enzyme family, recently identified as a critical driver of an oncogenic signature. Our findings suggest that this enzyme is active in the normal breast epithelium during DNA damage response. CONCLUSIONS: We demonstrate the practical application of a new method for assessing cell-type specific change in mixed cultures, especially the analysis of normal primary cultures, overcoming a major technical issue of dissecting the response of multiple cell types in a heterogeneous population.

Galectin-1 is associated with poor prognosis in patients with cutaneous head and neck cancer with perineural spread.

Spread of head and neck cancer along the cranial nerves is often a lethal complication of this tumour. Current treatment options include surgical resection and/or radiotherapy, but recurrence is a frequent event suggesting that our understanding of this tumour and its microenvironment is incomplete. In this study, we have analysed the nature of the perineural tumour microenvironment by immunohistochemistry with particular focus on immune cells and molecules, which might impair anti-tumour immunity. Moderate to marked lymphocyte infiltrates were present in 58.8% of the patient cohort including T cells, B cells and FoxP3-expressing T cells. While human leukocyte antigen (HLA) class I and more variably HLA class II were expressed on the tumour cells, this did not associate with patient survival or recurrence. In contrast, galectin-1 staining within lymphocyte areas of the tumour was significantly associated with a poorer patient outcome. Given the known role of galectin-1 in immune suppression, the data suggest that galectin inhibitors might improve the prognosis of patients with perineural spread of cancer.

The Enhanced liver fibrosis score is associated with clinical outcomes and disease progression in patients with chronic liver disease.

BACKGROUND AND AIMS: Current tools for risk stratification of chronic liver disease subjects are limited. We aimed to determine whether the serum-based ELF (Enhanced Liver Fibrosis) test predicted liver-related clinical outcomes, or progression to advanced liver disease, and to compare the performance of ELF to liver biopsy and non-invasive algorithms. METHODS: Three hundred patients with ELF scores assayed at the time of liver biopsy were followed up (median 6.1 years) for liver-related clinical outcomes (n = 16) and clear evidence of progression to advanced fibrosis (n = 18), by review of medical records and clinical data. RESULTS: Fourteen of 73 (19.2%) patients with ELF score indicative of advanced fibrosis (≥9.8, the manufacturer's cut-off) had a liver-related clinical outcome, compared to only two of 227 (<1%) patients with ELF score <9.8. In contrast, the simple scores APRI and FIB-4 would only have predicted subsequent decompensation in six and four patients respectively. A unit increase in ELF score was associated with a 2.53-fold increased risk of a liver-related event (adjusted for age and stage of fibrosis). In patients without advanced fibrosis on biopsy at recruitment, 55% (10/18) with an ELF score ≥9.8 showed clear evidence of progression to advanced fibrosis (after an average 6 years), whereas only 3.5% of those with an ELF score <9.8 (8/207) progressed (average 14 years). In these subjects, a unit increase in ELF score was associated with a 4.34-fold increased risk of progression. CONCLUSIONS: The ELF score is a valuable tool for risk stratification of patients with chronic liver disease.

Risk factors for current and future unmet supportive care needs of people with pancreatic cancer. A longitudinal study.

PURPOSE: This study aims to determine if the supportive care needs of people with pancreatic cancer change over time and identify the factors associated with current and future unmet needs. METHODS: Australian pancreatic cancer patients completed a self-administered survey at 0-6 months post-diagnosis (n = 116) then follow-up surveys 2 (n = 82) and 4 months (n = 50) later. The validated survey measured 34 needs across five domains. Weighted generalised estimating equations were used to identify factors associated with having ≥1 current or future moderate-to-high unmet need. RESULTS: The overall proportion of patients reporting ≥1 moderate-or-high-level need did not significantly change over time (baseline = 70 % to 4 months = 75 %), although there was a non-significant reduction in needs for patients who had a complete resection (71 to 63 %) and an increase in patients with locally advanced (73 to 85 %) or metastatic (66 to 88 %) disease. Higher levels of pain (OR 6.1, CI 2.4-15.3), anxiety (OR 3.3, CI 1.5-7.3) and depression (OR 3.2, CI 1.7-6.0) were significantly associated with current needs. People with pain (OR 4.9, CI 1.5-15.4), metastatic disease (OR 2.7, CI 0.7-10.0) or anxiety (OR 2.5, CI 0.7-8.6) had substantially higher odds of reporting needs at their next survey. The prevalence of needs was highest in the physical/daily living and psychological domains (both 53 % at baseline). Pain and anxiety had respectively the strongest associations with these domains. CONCLUSIONS: Careful and continued attention to pain control and psychological morbidity is paramount in addressing significant unmet needs, particularly for people with metastatic disease. Research on how best to coordinate this is crucial.

Genome-wide DNA methylation analysis of formalin-fixed paraffin embedded colorectal cancer tissue.

Formalin fixation and embedding of clinical tissue samples in paraffin is a common method for archiving biological material. These samples are often well annotated and provide an invaluable resource for research. However, this process of fixation and storage of tissue leads to DNA damage and fragmentation. The use of DNA from formalin fixed, paraffin-embedded (FFPE) tissue to interrogate methylation levels on a genome-wide scale can pose challenges. We compared fresh and matched FFPE tissue DNA samples using the Illumina Infinium HD Human Methylation 450K BeadChip platform with a companion application for repair and "restoration" of DNA from FFPE tissue. Our results showed good correlation between fresh and FFPE sample data. FFPE DNA captured 99% of the CpG sites on the array on average. Significant cancer subgroups based on the CpG island methylator phenotype (CIMP) were clearly distinguished for both fresh and FFPE sample sets with cluster and scaling analysis. The DNA methylation status for the five standard CIMP panel genes which was evaluated for all samples by the MethyLight assay was correctly assigned in both fresh and FFPE samples by the array data. We conclude that the "restoration" method followed by assay on the Infinium HD Human Methylation 450K microarray can produce good quality data for DNA from FFPE samples.

Augmented renal clearance in the ICU: results of a multicenter observational study of renal function in critically ill patients with normal plasma creatinine concentrations*.

OBJECTIVE: To describe the prevalence and natural history of augmented renal clearance in a cohort of recently admitted critically ill patients with normal plasma creatinine concentrations. DESIGN: Multicenter, prospective, observational study. SETTING: Four, tertiary-level, university-affiliated, ICUs in Australia, Singapore, Hong Kong, and Portugal. PATIENTS: Study participants had to have an expected ICU length of stay more than 24 hours, no evidence of absolute renal impairment (admission plasma creatinine < 120 µmol/L), and no history of prior renal replacement therapy or chronic kidney disease. Convenience sampling was used at each participating site. INTERVENTIONS: Eight-hour urinary creatinine clearances were collected daily, as the primary method of measuring renal function. Augmented renal clearance was defined by a creatinine clearance more than or equal to 130 mL/min/1.73 m. Additional demographic, physiological, therapeutic, and outcome data were recorded prospectively. MEASUREMENTS AND MAIN RESULTS: Nine hundred thirty-two patients were admitted to the participating ICUs over the study period, and 281 of which were recruited into the study, contributing 1,660 individual creatinine clearance measures. The mean age (95% CI) was 54.4 years (52.5-56.4 yr), Acute Physiology and Chronic Health Evaluation II score was 16 (15.2-16.7), and ICU mortality was 8.5%. Overall, 65.1% manifested augmented renal clearance on at least one occasion during the first seven study days; the majority (74%) of whom did so on more than or equal to 50% of their creatinine clearance measures. Using a mixed-effects model, the presence of augmented renal clearance on study day 1 strongly predicted (p = 0.019) sustained elevation of creatinine clearance in these patients over the first week in ICU. CONCLUSIONS: Augmented renal clearance appears to be a common finding in this patient group, with sustained elevation of creatinine clearance throughout the first week in ICU. Future studies should focus on the implications for accurate dosing of renally eliminated pharmaceuticals in patients with augmented renal clearance, in addition to the potential impact on individual clinical outcomes.

Quality of life and treatment response among women with platinum-resistant versus platinum-sensitive ovarian cancer treated for progression: a prospective analysis.

OBJECTIVE: Most women with ovarian cancer relapse and undergo further chemotherapy however evidence regarding the benefits of this for women with platinum-resistant disease is limited. Our objective was to determine whether there was a quality of life improvement or treatment response among women treated for platinum-resistant recurrent ovarian cancer. METHODS: We combined data from 2 studies where women treated with chemotherapy for recurrent ovarian cancer (n=172) completed a quality of life questionnaire every 3 months. Cancers were classified as platinum-resistant if they progressed within 6 months of completing first-line chemotherapy. Mixed effects models were used to analyze change in quality of life during the first 6 months after second-line chemotherapy. RESULTS: One-quarter of women (n=44) were classified as having platinum-resistant disease. Overall, their quality of life did not significantly increase or decrease, following commencement of second-line chemotherapy (least square mean scores=107, 105, 103 at chemotherapy start, 3 and 6 months later, respectively), although 26% of these women reported a meaningful increase and 31% reported a meaningful decline. One-third of the platinum-resistant group responded (11% complete and 21% partial response) to second-line chemotherapy, and this figure increased to 54% among the subset (36%) re-treated with platinum-based agents with or without other agents. Preliminary analyses suggest that quality of life may be higher at chemotherapy initiation in women whose disease responded (median score 121 vs 110). CONCLUSIONS: Overall, quality of life appears to be maintained in women with platinum-resistant ovarian cancer who receive further chemotherapy and some women respond to re-treatment.

Hepatic iron deposition does not predict extrahepatic iron loading in mouse models of hereditary hemochromatosis.

Hereditary hemochromatosis is characterized by tissue iron loading and associated organ damage. However, the phenotype can be highly variable. The relationship between iron loading of different organs and the temporal nature of its deposition is still not well understood. We examined the progression of tissue iron loading in three mouse models to advance our understanding of the natural history of iron deposition in hereditary hemochromatosis. Wild-type, Hfe(-/-), Tfr2(-/-), and Hfe(-/-)/Tfr2(-/-) mice were analyzed at 3, 5, 10, 26, and 52 weeks, respectively. Hepatic, splenic, cardiac, and pancreatic iron concentrations were determined. Expression of both iron-regulatory and fibrosis genes was determined by quantitative real-time PCR in livers and hearts of 52-week-old mice. In all models, hepatic iron increased rapidly, plateauing before 10 weeks at different levels, depending on the genotype. Iron deposition in the pancreas and heart occurred after maximal iron loading of the liver was reached and was most marked in the Hfe(-/-)/Tfr2(-/-) mice. Although a significant positive correlation was identified between pancreatic and cardiac iron in all models at 52 weeks, there was no correlation between hepatic and either pancreatic or cardiac iron. There is variability in the timing and extent of tissue iron loading within a genotype, suggesting that hepatic iron levels in hereditary hemochromatosis may not accurately predict the iron content of other organs.

Integrative Genome-Scale DNA Methylation Analysis of a Large and Unselected Cohort Reveals 5 Distinct Subtypes of Colorectal Adenocarcinomas.

BACKGROUND & AIMS: Colorectal cancer is an epigenetically heterogeneous disease, however, the extent and spectrum of the CpG island methylator phenotype (CIMP) is not clear. METHODS: Genome-scale methylation and transcript expression were measured by DNA Methylation and RNA expression microarray in 216 unselected colorectal cancers, and findings were validated using The Cancer Genome Atlas 450K and RNA sequencing data. Mutations in epigenetic regulators were assessed using CIMP-subtyped Cancer Genome Atlas exomes. RESULTS: CIMP-high cancers dichotomized into CIMP-H1 and CIMP-H2 based on methylation profile. KRAS mutation was associated significantly with CIMP-H2 cancers, but not CIMP-H1 cancers. Congruent with increasing methylation, there was a stepwise increase in patient age from 62 years in the CIMP-negative subgroup to 75 years in the CIMP-H1 subgroup (P < .0001). CIMP-H1 predominantly comprised consensus molecular subtype 1 cancers (70%) whereas consensus molecular subtype 3 was over-represented in the CIMP-H2 subgroup (55%). Polycomb Repressive Complex-2 (PRC2)-marked loci were subjected to significant gene body methylation in CIMP cancers (P < 1.6 × 10-78). We identified oncogenes susceptible to gene body methylation and Wnt pathway antagonists resistant to gene body methylation. CIMP cluster-specific mutations were observed in chromatin remodeling genes, such as in the SWItch/Sucrose Non-Fermentable and Chromodomain Helicase DNA-Binding gene families. CONCLUSIONS: There are 5 clinically and molecularly distinct subgroups of colorectal cancer. We show a striking association between CIMP and age, sex, and tumor location, and identify a role for gene body methylation in the progression of serrated neoplasia. These data support our recent findings that CIMP is uncommon in young patients and that BRAF mutant polyps in young patients may have limited potential for malignant progression.

LobSig is a multigene predictor of outcome in invasive lobular carcinoma.

Invasive lobular carcinoma (ILC) is the most common special type of breast cancer, and is characterized by functional loss of E-cadherin, resulting in cellular adhesion defects. ILC typically present as estrogen receptor positive, grade 2 breast cancers, with a good short-term prognosis. Several large-scale molecular profiling studies have now dissected the unique genomics of ILC. We have undertaken an integrative analysis of gene expression and DNA copy number to identify novel drivers and prognostic biomarkers, using in-house (n = 25), METABRIC (n = 125) and TCGA (n = 146) samples. Using in silico integrative analyses, a 194-gene set was derived that is highly prognostic in ILC (P = 1.20 × 10-5)-we named this metagene 'LobSig'. Assessing a 10-year follow-up period, LobSig outperformed the Nottingham Prognostic Index, PAM50 risk-of-recurrence (Prosigna), OncotypeDx, and Genomic Grade Index (MapQuantDx) in a stepwise, multivariate Cox proportional hazards model, particularly in grade 2 ILC cases (χ 2, P = 9.0 × 10-6), which are difficult to prognosticate clinically. Importantly, LobSig status predicted outcome with 94.6% accuracy amongst cases classified as 'moderate-risk' according to Nottingham Prognostic Index in the METABRIC cohort. Network analysis identified few candidate pathways, though genesets related to proliferation were identified, and a LobSig-high phenotype was associated with the TCGA proliferative subtype (χ 2, P < 8.86 × 10-4). ILC with a poor outcome as predicted by LobSig were enriched with mutations in ERBB2, ERBB3, TP53, AKT1 and ROS1. LobSig has the potential to be a clinically relevant prognostic signature and warrants further development.

Prevalence and stability of antibodies to thirteen polyomaviruses and association with cutaneous squamous cell carcinoma: A population-based study.

BACKGROUND: Several new members of the human polyomavirus (HPyV) family that infect human skin and are potentially oncogenic have been identified in the last decade. OBJECTIVES: To investigate prospectively the seroprevalence and stability of 13 PyVs, and possible associations with different risk factors and cutaneous squamous cell carcinoma (cSCC). STUDY DESIGN: In this Australian population-based longitudinal study sera were collected at baseline in 1992 or during the next 4 years from 688 people. Of the 688, 226 developed a new cSCC between blood collection and the final follow up in 2003. The remaining 462 served as controls. Among the 462 controls, 161 had a second serum sample from 2003 analysed. Seroprevalence of 10 human PyVs (BKV, JCV, KIV, WUV, MCV, TSV, HPyV6, HPyV7, HPyV9 and HPyV10) and three non-human PyVs (SV40, LPV and ChPyV) was assessed using multiplex serology. RESULTS: There was no significant difference in PyV seroprevalence between people who developed cSCC during follow-up compared to those who did not. WUV and HPyV10 showed the highest serostability (93%) and JCV VP1 and SV40 VP1 the lowest (84%) over a 9-year time period (range 7-11 years). CONCLUSIONS: We found no evidence that HPyV seroprevalence is associated with subsequent development of cSCC and observed variable stability of antibodies to polyomaviruses.

Hepatic iron concentration correlates with insulin sensitivity in nonalcoholic fatty liver disease.

Rodent and cell-culture models support a role for iron-related adipokine dysregulation and insulin resistance in the pathogenesis of nonalcoholic fatty liver disease (NAFLD); however, substantial human data are lacking. We examined the relationship between measures of iron status, adipokines, and insulin resistance in patients with NAFLD in the presence and absence of venesection. This study forms part of the Impact of Iron on Insulin Resistance and Liver Histology in Nonalcoholic Steatohepatitis (IIRON2) study, a prospective randomized controlled trial of venesection for adults with NAFLD. Paired serum samples at baseline and 6 months (end of treatment) in controls (n = 28) and patients who had venesection (n = 23) were assayed for adiponectin, leptin, resistin, retinol binding protein-4, tumor necrosis factor α, and interleukin-6, using a Quantibody, customized, multiplexed enzyme-linked immunosorbent assay array. Hepatic iron concentration (HIC) was determined using MR FerriScan. Unexpectedly, analysis revealed a significant positive correlation between baseline serum adiponectin concentration and HIC, which strengthened after correction for age, sex, and body mass index (rho = 0.36; P = 0.007). In addition, there were significant inverse correlations between HIC and measures of insulin resistance (adipose tissue insulin resistance (Adipo-IR), serum insulin, serum glucose, homeostasis model assessment of insulin resistance, hemoglobin A1c, and hepatic steatosis), whereas a positive correlation was noted with the insulin sensitivity index. Changes in serum adipokines over 6 months did not differ between the control and venesection groups. Conclusion: HIC positively correlates with serum adiponectin and insulin sensitivity in patients with NAFLD. Further study is required to establish causality and mechanistic explanations for these associations and their relevance in the pathogenesis of insulin resistance and NAFLD. (Hepatology Communications 2018;2:644-653).

NLRP1 restricts butyrate producing commensals to exacerbate inflammatory bowel disease.

Anti-microbial signaling pathways are normally triggered by innate immune receptors when detecting pathogenic microbes to provide protective immunity. Here we show that the inflammasome sensor Nlrp1 aggravates DSS-induced experimental mouse colitis by limiting beneficial, butyrate-producing Clostridiales in the gut. The colitis-protective effects of Nlrp1 deficiency are thus reversed by vancomycin treatment, but recapitulated with butyrate supplementation in wild-type mice. Moreover, an activating mutation in Nlrp1a increases IL-18 and IFNγ production, and decreases colonic butyrate to exacerbate colitis. We also show that, in patients with ulcerative colitis, increased NLRP1 in inflamed regions of the colon is associated with increased IFN-γ. In this context, NLRP1, IL-18 or IFN-γ expression negatively correlates with the abundance of Clostridiales in human rectal mucosal biopsies. Our data identify the NLRP1 inflammasome to be a key negative regulator of protective, butyrate-producing commensals, which therefore promotes inflammatory bowel disease.