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1.  T Cells Detect Intracellular DNA but Fail to Induce Type I IFN Responses: Implications for Restriction of HIV Replication 
PLoS ONE  2014;9(1):e84513.
HIV infects key cell types of the immune system, most notably macrophages and CD4+ T cells. Whereas macrophages represent an important viral reservoir, activated CD4+ T cells are the most permissive cell types supporting high levels of viral replication. In recent years, it has been appreciated that the innate immune system plays an important role in controlling HIV replication, e.g. via interferon (IFN)-inducible restriction factors. Moreover, innate immune responses are involved in driving chronic immune activation and the pathogenesis of progressive immunodeficiency. Several pattern recognition receptors detecting HIV have been reported, including Toll-like receptor 7 and Retinoic-inducible gene-I, which detects viral RNA. Here we report that human primary T cells fail to induce strong IFN responses, despite the fact that this cell type does express key molecules involved in DNA signaling pathways. We demonstrate that the DNA sensor IFI16 migrates to sites of foreign DNA localization in the cytoplasm and recruits the signaling molecules stimulator of IFN genes and Tank-binding kinase, but this does not result in expression of IFN and IFN-stimulated genes. Importantly, we show that cytosolic DNA fails to affect HIV replication. However, exogenous treatment of activated T cells with type I IFN has the capacity to induce expression of IFN-stimulated genes and suppress HIV replication. Our data suggest the existence of an impaired DNA signaling machinery in T cells, which may prevent this cell type from activating cell-autonomous anti-HIV responses. This phenomenon could contribute to the high permissiveness of CD4+ T cells for HIV-1.
doi:10.1371/journal.pone.0084513
PMCID: PMC3880311  PMID: 24404168
2.  Common variable immunodeficiency unmasked by treatment of immune thrombocytopenic purpura with Rituximab 
BMC Hematology  2013;13:4.
Background
Hypogammaglobulinemia may be part of several different immunological or malignant conditions, and its origin is not always obvious. Furthermore, although autoimmune cytopenias are known to be associated with common variable immunodeficiency (CVID) and even may precede signs of immunodeficiency, this is not always recognized. Despite novel insight into the molecular immunology of common variable immunodeficiency, several areas of uncertainty remain. In addition, the full spectrum of immunological effects of the B cell depleting anti-CD20 antibody Rituximab has not been fully explored. To our knowledge this is the first report of development of CVID in a patient with normal immunoglobulin prior to Rituximab treatment.
Case presentation
Here we describe the highly unusual clinical presentation of a 34-year old Caucasian male with treatment refractory immune thrombocytopenic purpura and persistent lymphadenopathy, who was splenectomized and received multiple courses of high-dose corticosteroid before treatment with Rituximab resulted in a sustained response. However, in the setting of severe pneumococcal meningitis, hypogammaglobulinemia was diagnosed. An extensive immunological investigation was performed in order to characterize his immune status, and to distinguish between a primary immunodeficiency and a side effect of Rituximab treatment. We provide an extensive presentation and discussion of the literature on the basic immunology of CVID, the mechanism of action of Rituximab, and the immunopathogenesis of hypogammaglobulinemia observed in this patient.
Conclusions
We suggest that CVID should be ruled out in any patient with immune cytopenias in order to avoid diagnostic delay. Likewise, we stress the importance of monitoring immunoglobulin levels before, during, and after Rituximab therapy to identify patients with hypogammaglobulinemia to ensure initiation of immunoglobulin replacement therapy in order to avoid life-threatening invasive bacterial infections. Recent reports indicate that Rituximab is not contra-indicated for the treatment of CVID-associated thrombocytopenia, however concomitant immunoglobulin substitution therapy is of fundamental importance to minimize the risk of infections. Therefore, lessons can be learned from this case report by clinicians caring for patients with immunodeficiencies, haematological diseases or other autoimmune disorders, particularly, when Rituximab treatment may be considered.
doi:10.1186/2052-1839-13-4
PMCID: PMC3776283  PMID: 24499503
Hypogammaglobulinemia; Common variable immunodeficiency; Immune thrombocytopenic purpura; Rituximab
3.  Statin Therapy and Mortality in HIV-Infected Individuals; A Danish Nationwide Population-Based Cohort Study 
PLoS ONE  2013;8(3):e52828.
Background
Recent studies have suggested that statins possess diverse immune modulatory and anti-inflammatory properties. As statins might attenuate inflammation, statin therapy has been hypothesized to reduce mortality in HIV-infected individuals. We therefore used a Danish nationwide cohort of HIV-infected individuals to estimate the impact of statin use on mortality before and after a diagnosis of cardiovascular disease, chronic kidney disease or diabetes.
Methods
We identified all Danish HIV-infected individuals (1,738) who initiated HAART after 1 January 1998, and achieved virological suppression within 180 days. Date of first redemption of a prescription of statin was obtained from the Danish National Prescription Registry. We used Poisson regression analysis to assess adjusted mortality rate ratios (aMRR). First, time was censored at date of virological failure (VL >500 copies/ml). Second, time was not censored at virological failure. All analyses were adjusted for potential confounders.
Results
In the analyses confined to observation time without virological failure (+ censoring) statin therapy was associated with a non-statistically significant reduced rate of death (aMRR 0.75; 95% CI: 0.33–1.68). No difference was observed in the analysis with no censoring (aMRR 1.17; 95% CI: 0.66–2.07). Use of statin seemed to reduce mortality in individuals after a diagnosis of comorbidity {(+ censoring: aMRR: 0.34; 95% CI: 0.11–1.04), (−censoring: aMRR: 0.64; 95% CI: 0.32–1.29)}. No difference in rate of death could be detected before first date of diagnosis of comorbidity {(+ censoring: aMRR: 1.12; 95% CI: 0.34–3.62), (−censoring: aMRR: 0.90; 95% CI: 0.28–2.88)}.
Conclusion
Statin therapy might reduce all-cause mortality in HIV-infected individuals, but the impact on individuals with no comorbidity seems small or absent. An unambiguous proof of a causal relation can only be obtained in a randomized controlled trial, but the sample size predicted may be prohibitive for its conduct.
doi:10.1371/journal.pone.0052828
PMCID: PMC3587599  PMID: 23469159
4.  Prevalence of infective endocarditis in patients with Staphylococcus aureus bacteraemia: the value of screening with echocardiography 
Aims
Staphylococcus aureus infective endocarditis (IE) is a critical medical condition associated with a high morbidity and mortality. In the present study, we prospectively evaluated the importance of screening with echocardiography in an unselected S. aureus bacteraemia (SAB) population.
Methods and results
From 1 January 2009 to 31 August 2010, a total of 244 patients with SAB at six Danish hospitals underwent screening echocardiography. The inclusion rate was 73% of all eligible patients (n= 336), and 53 of the 244 included patients (22%; 95% CI: 17–27%) were diagnosed with definite IE. In patients with native heart valves the prevalence was 19% (95% CI: 14–25%) compared with 38% (95% CI: 20–55%) in patients with prosthetic heart valves and/or cardiac rhythm management devices (P= 0.02). No difference was found between Main Regional Hospitals and Tertiary Cardiac Hospitals, 20 vs. 23%, respectively (NS). The prevalence of IE in high-risk patients with one or more predisposing condition or clinical evidence of IE were significantly higher compared with low-risk patients with no additional risk factors (38 vs. 5%; P < 0.001). IE was associated with a higher 6 months mortality, 14(26%) vs. 28(15%) in SAB patients without IE, respectively (P < 0.05).
Conclusion
SAB patients carry a high risk for development of IE, which is associated with a worse prognosis compared with uncomplicated SAB. The presenting symptoms and clinical findings associated with IE are often non-specific and echocardiography should always be considered as part of the initial evaluation of SAB patients.
doi:10.1093/ejechocard/jer023
PMCID: PMC3117467  PMID: 21685200
Infective endocarditis; Echocardiography; Staphylococcus aureus; Screening
5.  Genomic HIV RNA Induces Innate Immune Responses through RIG-I-Dependent Sensing of Secondary-Structured RNA 
PLoS ONE  2012;7(1):e29291.
Background
Innate immune responses have recently been appreciated to play an important role in the pathogenesis of HIV infection. Whereas inadequate innate immune sensing of HIV during acute infection may contribute to failure to control and eradicate infection, persistent inflammatory responses later during infection contribute in driving chronic immune activation and development of immunodeficiency. However, knowledge on specific HIV PAMPs and cellular PRRs responsible for inducing innate immune responses remains sparse.
Methods/Principal Findings
Here we demonstrate a major role for RIG-I and the adaptor protein MAVS in induction of innate immune responses to HIV genomic RNA. We found that secondary structured HIV-derived RNAs induced a response similar to genomic RNA. In primary human peripheral blood mononuclear cells and primary human macrophages, HIV RNA induced expression of IFN-stimulated genes, whereas only low levels of type I IFN and tumor necrosis factor α were produced. Furthermore, secondary structured HIV-derived RNA activated pathways to NF-κB, MAP kinases, and IRF3 and co-localized with peroxisomes, suggesting a role for this organelle in RIG-I-mediated innate immune sensing of HIV RNA.
Conclusions/Significance
These results establish RIG-I as an innate immune sensor of cytosolic HIV genomic RNA with secondary structure, thereby expanding current knowledge on HIV molecules capable of stimulating the innate immune system.
doi:10.1371/journal.pone.0029291
PMCID: PMC3250430  PMID: 22235281
6.  Impact of Non-HIV and HIV Risk Factors on Survival in HIV-Infected Patients on HAART: A Population-Based Nationwide Cohort Study 
PLoS ONE  2011;6(7):e22698.
Background
We determined the impact of three factors on mortality in HIV-infected patients who had been on highly active antiretroviral therapy (HAART) for at least one year: (1) insufficient response to (HAART) and presence of AIDS-defining diseases, (2) comorbidity, and (3) drug and alcohol abuse and compared the mortality to that of the general population.
Methodology/Principal Findings
In a Danish nationwide, population-based cohort study, we used population based registries to identify (1) all Danish HIV-infected patients who started HAART in the period 1 January 1998–1 July 2009, and (2) a comparison cohort of individuals matched on date of birth and gender (N = 2,267 and 9,068, respectively). Study inclusion began 1 year after start of HAART. Patients were categorised hierarchically in four groups according to the three risk factors, which were identified before study inclusion. The main outcome measure was probability of survival from age 25 to 65 years. The probability of survival from age 25 to age 65 was substantially lower in HIV patients [0.48 (95% confidence interval (CI) 0.42–0.55)] compared to the comparison cohort [0.88 (0.86 to 0.90)]. However, in HIV patients with no risk factors (N = 871) the probability of survival was equivalent to that of the general population [0.86 (95% CI 0.77–0.92)]. In contrast, the probability of survival was 0.58 in patients with HIV risk factors (N = 704), 0.30 in patients with comorbidities (N = 479), and 0.03 in patients with drug or alcohol abuse (N = 313).
Conclusions
The increased risk of death in HIV-infected individuals is mainly attributable to risk factors that can be identified prior to or in the initial period of antiretroviral treatment. Mortality in patients without risk factors on a successful HAART is almost identical to that of the non–HIV-infected population.
doi:10.1371/journal.pone.0022698
PMCID: PMC3143183  PMID: 21799935
7.  Head and neck cancer in HIV patients and their parents: a Danish cohort study 
Clinical Epidemiology  2011;3:217-227.
Background:
The mechanism for the increased risk of head and neck cancer (HNC) observed in HIV patients is controversial. We hypothesized that family-related risk factors increase the risk of HNC why we estimated the risk of this type of cancer in both HIV patients and their parents.
Methods:
We estimated the cumulative incidence and incidence rate ratios (IRRs) of HNC in 1) a population of all Danish HIV patients identified from the Danish HIV Cohort Study (n = 5053) and a cohort of population controls matched on age and gender (n = 50,530) (study period; 1995–2009) and 2) the parents of HIV patients and population controls (study period 1978–2009). To assess the possible impact of human papilloma virus (HPV)–associated cancers, the sites of squamous cell HNCs were categorized as HPV related, potentially HPV related, and potentially HPV unrelated.
Results:
Seventeen (0.3%) HIV patients vs 80 (0.2%) population controls were diagnosed with HNC cancer in the observation period. HIV patients had an increased risk of HNC (IRR 3.05 [95% CI 1.81–5.15]). The IRR was considerably increased in HIV patients older than 50 years (adjusted IRR; 4.58 [95% CI 2.24–9.35]), diagnosed after 1995 (adjusted IRR 6.31 [95% CI 2.82–14.08]), previous or current smoker (adjusted IRR 4.51 [95% CI 2.47–8.23]), with baseline CD4 count 350 cells/μL (adjusted IRR; 3.89 [95% CI 1.95–7.78]), and men heterosexually infected with HIV (adjusted IRR 5.54 [95% CI 1.96–15.66]). Fifteen (83%) of the HIV patients diagnosed with HNC were current or former smokers. The IRR of squamous cell HNC in HIV patients was high at HPV-relate sites, potentially HPV-related sites, and potentially HPV-unrelated sites. Both fathers and mothers of HIV patients had an increased risk of HNC (adjusted IRR for fathers 1.78 [95% CI 1.28–2.48], adjusted IRR for mothers 2.07 [95% CI 1.05–4.09]).
Conclusion:
HIV appears to be a marker of behavioral or family-related risk factors that affect the incidence of HNC in HIV patients.
doi:10.2147/CLEP.S19875
PMCID: PMC3157492  PMID: 21857789
HIV; head and neck cancer incidence; matched cohort; population controls; parents
8.  Lung cancer in HIV patients and their parents: A Danish cohort study 
BMC Cancer  2011;11:272.
Background
HIV patients are known to be at increased risk of lung cancer but the risk factors behind this are unclear.
Methods
We estimated the cumulative incidence and relative risk of lung cancer in 1) a population of all Danish HIV patients identified from the Danish HIV Cohort Study (n = 5,053) and a cohort of population controls matched on age and gender (n = 50,530) (study period; 1995 - 2009) and 2) their parents (study period; 1969 - 2009). Mortality and relative risk of death after a diagnosis of lung cancer was estimated in both populations.
Results
29 (0.6%) HIV patients vs. 183 (0.4%) population controls were diagnosed with lung cancer in the observation period. HIV patients had an increased risk of lung cancer (adjusted incidence rate ratio (IRR); 2.38 (95% CI; 1.61 - 3.53)). The IRR was considerably increased in HIV patients who were smokers or former smokers (adjusted IRR; 4.06 (95% CI; 2.66 - 6.21)), male HIV patients with heterosexual route of infection (adjusted IRR; 4.19 (2.20 - 7.96)) and HIV patients with immunosuppression (adjusted IRR; 3.25 (2.01 - 5.24)). Both fathers and mothers of HIV patients had an increased risk of lung cancer (adjusted IRR for fathers; 1.31 (95% CI: 1.09 - 1.58), adjusted IRR for mothers 1.35 (95% CI: 1.07 - 1.70)). Mortality after lung cancer diagnose was increased in HIV patients (adjusted mortality rate ratio 2.33 (95%CI; 1.51 - 3.61), but not in the parents. All HIV patients diagnosed with lung cancer were smokers or former smokers.
Conclusion
The risk was especially increased in HIV patients who were smokers or former smokers, heterosexually infected men or immunosuppressed. HIV appears to be a marker of behavioural or family related risk factors that affect the incidence of lung cancer in HIV patients.
doi:10.1186/1471-2407-11-272
PMCID: PMC3135571  PMID: 21702995
HIV; lung cancer incidence; matched cohort; population controls; parents; immunosuppression
9.  Incidence, risk factors and mortality of tuberculosis in Danish HIV patients 1995-2007 
Background
Human Immunodeficiency Virus (HIV) infection predisposes to tuberculosis (TB). We described incidence, risk factors and prognosis of TB in HIV-1 infected patients during pre (1995-1996), early (1997-1999), and late Highly Active Antiretroviral Therapy (HAART) (2000-2007) periods.
Methods
We included patients from a population-based, multicenter, nationwide cohort. We calculated incidence rates (IRs) and mortality rates (MRs). Cox's regression analysis was used to estimate risk factors for TB infection with HAART initiation included as time updated variable. Kaplan-Meier was used to estimate mortality after TB.
Results
Among 2,668 patients identified, 120 patients developed TB during the follow-up period. The overall IR was 8.2 cases of TB/1,000 person-years of follow-up (PYR). IRs decreased during the pre-, early and late-HAART periods (37.1/1000 PYR, 12.9/1000 PYR and 6.5/1000 PYR respectively). African and Asian origin, low CD4 cell count and heterosexual and injection drug user route of HIV transmission were risk factors for TB and start of HAART reduced the risk substantially. The overall MR in TB patients was 34.4 deaths per 1,000 PYR (95% Confidence Interval: 22.0-54.0) and was highest in the first two years after the diagnosis of TB.
Conclusions
Incidence of TB still associated with conventional risk factors as country of birth, low CD4 count and route of HIV infection while HAART reduces the risk substantially. The mortality in this patient population is high in the first two years after TB diagnosis.
doi:10.1186/1471-2466-11-26
PMCID: PMC3115926  PMID: 21605366
10.  Long-term mortality in HIV patients virally suppressed for more than three years with incomplete CD4 recovery: A cohort study 
BMC Infectious Diseases  2010;10:318.
Background
The mortality in patients with persistent low CD4 count despite several years of HAART with sustained viral suppression is poorly documented. We aimed to identify predictors for inadequate CD4 cell recovery and estimate mortality in patients with low CD4 count but otherwise successful HAART.
Method
In a nationwide cohort of HIV patients we identified all individuals who started HAART before 1 January 2005 with CD4 cell count ≤ 200 cells/μL and experienced three years with sustained viral suppression. Patients were categorized according to CD4 cell count after the three years suppressed period (≤ 200 cells/μL; immunological non-responders (INRs), >200 cells/μL; immunological responders (IRs)). We used logistic regression and Kaplan-Meier analysis to estimated risk factors and mortality for INRs compared to IRs.
Results
We identified 55 INRs and 236 IRs. In adjusted analysis age > 40 years and > one year from first CD4 cell count ≤ 200 cells/μL to start of the virologically suppressed period were associated with increased risk of INR. INRs had substantially higher mortality compared to IRs. The excess mortality was mainly seen in the INR group with > one year of immunological suppression prior to viral suppression and injection drug users (IDUs).
Conclusion
Age and prolonged periods of immune deficiency prior to successful HAART are risk factors for incomplete CD4 cell recovery. INRs have substantially increased long-term mortality mainly associated with prolonged immunological suppression prior to viral suppression and IDU.
doi:10.1186/1471-2334-10-318
PMCID: PMC2988053  PMID: 21044307
11.  Chronic hepatitis caused by persistent parvovirus B19 infection 
BMC Infectious Diseases  2010;10:246.
Background
Human infection with parvovirus B19 may lead to a diverse spectrum of clinical manifestations, including benign erythema infectiosum in children, transient aplastic crisis in patients with haemolytic anaemia, and congenital hydrops foetalis. These different diseases represent direct consequences of the ability of parvovirus B19 to target the erythroid cell lineage. However, accumulating evidence suggests that this virus can also infect other cell types resulting in diverse clinical manifestations, of which the pathogenesis remains to be fully elucidated. This has prompted important questions regarding the tropism of the virus and its possible involvement in a broad range of infectious and autoimmune medical conditions.
Case Presentation
Here, we present an unusual case of persistent parvovirus B19 infection as a cause of chronic hepatitis. This patient had persistent parvovirus B19 viraemia over a period of more than four years and displayed signs of chronic hepatitis evidenced by fluctuating elevated levels of ALAT and a liver biopsy demonstrating chronic hepatitis. Other known causes of hepatitis and liver damage were excluded. In addition, the patient was evaluated for immunodeficiency, since she had lymphopenia both prior to and following clearance of parvovirus B19 infection.
Conclusions
In this case report, we describe the current knowledge on the natural history and pathogenesis of parvovirus B19 infection, and discuss the existing evidence of parvovirus B19 as a cause of acute and chronic hepatitis. We suggest that parvovirus B19 was the direct cause of this patient's chronic hepatitis, and that she had an idiopathic lymphopenia, which may have predisposed her to persistent infection, rather than bone marrow depression secondary to infection. In addition, we propose that her liver involvement may have represented a viral reservoir. Finally, we suggest that clinicians should be aware of parvovirus B19 as an unusual aetiology of chronic hepatitis, when other causes have been ruled out.
doi:10.1186/1471-2334-10-246
PMCID: PMC2936411  PMID: 20727151
12.  Clinical, virological and immunological responses in Danish HIV patients receiving raltegravir as part of a salvage regimen 
Clinical Epidemiology  2010;2:145-151.
Background:
Raltegravir is the first integrase inhibitor approved for treatment of HIV-infected patients harboring multiresistant viruses.
Methods:
From a Danish population-based nationwide cohort of HIV patients we identified the individuals who initiated a salvage regimen including raltegravir and a matched cohort of HIV-infected patients initiating HAART for the first time. We compared these two cohorts for virological suppression, gain in CD4 count, and time to first change of initial regimen.
Results:
We identified 32 raltegravir patients and 64 HIV patients who initiated HAART for the first time in the period 1 January 2006 to 1 July 2009. The virological and immunological responses in the raltegravir patients were comparable to those seen in the control cohort. No patients in the two cohorts died and no patients terminated raltegravir treatment in the observation period. Time to first change of initial regimen was considerably shorter for HAART-naïve patients.
Conclusion:
We conclude that salvage regimens including raltegravir have high effectiveness in the everyday clinical setting. The effectiveness of the regimens is comparable to that observed for patients initiating HAART for the first time. The risk of change in the salvage regimens after initiation of raltegravir is low.
PMCID: PMC2943192  PMID: 20865112
HIV; raltegravir; salvage regime; efficacy; matched cohort
13.  Innate immune recognition and activation during HIV infection 
Retrovirology  2010;7:54.
The pathogenesis of HIV infection, and in particular the development of immunodeficiency, remains incompletely understood. Whichever intricate molecular mechanisms are at play between HIV and the host, it is evident that the organism is incapable of restricting and eradicating the invading pathogen. Both innate and adaptive immune responses are raised, but they appear to be insufficient or too late to eliminate the virus. Moreover, the picture is complicated by the fact that the very same cells and responses aimed at eliminating the virus seem to play deleterious roles by driving ongoing immune activation and progressive immunodeficiency. Whereas much knowledge exists on the role of adaptive immunity during HIV infection, it has only recently been appreciated that the innate immune response also plays an important part in HIV pathogenesis. In this review, we present current knowledge on innate immune recognition and activation during HIV infection based on studies in cell culture, non-human primates, and HIV-infected individuals, and discuss the implications for the understanding of HIV immunopathogenesis.
doi:10.1186/1742-4690-7-54
PMCID: PMC2904714  PMID: 20569472
14.  Functional Effects of KCNE3 Mutation and its Role in the Development of Brugada Syndrome 
Introduction
The Brugada Syndrome (BrS), an inherited syndrome associated with a high incidence of sudden cardiac arrest, has been linked to mutations in four different genes leading to a loss of function in sodium and calcium channel activity. Although the transient outward current (Ito) is thought to play a prominent role in the expression of the syndrome, mutations in Ito-related genes have not been identified as yet.
Methods and Results
One hundred and five probands with BrS were screened for ion channel gene mutations using single strand conformation polymorphism (SSCP) electrophoresis and direct sequencing. A missense mutation (R99H) in KCNE3 (MiRP2) was detected in one proband. The R99H mutation was found 4/4 phenotype positive and 0/3 phenotype-negative family members. Chinese hamster ovary (CHO)-K1 cells were co-transfected using wild-type (WT) or mutant KCNE3 and either WT KCND3 or KCNQ1. Whole-cell patch clamp studies were performed after 48 hours. Interactions between Kv4.3 and KCNE3 were analyzed in co-immunoprecipitation experiments in human atrial samples. Co-transfection of R99H-KCNE3 with KCNQ1 produced no alteration in current magnitude or kinetics. However, co-transfection of R99H KCNE3 with KCND3 resulted in a significant increase in the Ito intensity compared to WT KCNE3+KCND3. Using tissues isolated from left atrial appendages of human hearts, we also demonstrate that Kv4.3 and KCNE3 can be co-immunoprecipitated.
Conclusions
These results provide definitive evidence for a functional role of KCNE3 in the modulation of Ito in the human heart and suggest that mutations in KCNE3 can underlie the development of BrS.
doi:10.1161/CIRCEP.107.748103
PMCID: PMC2585750  PMID: 19122847
Genetics; Sudden Cardiac Death; Potassium Channels; Channelopathy; Electrophysiology
15.  Arsenic in Drinking-Water and Risk for Cancer in Denmark 
Environmental Health Perspectives  2007;116(2):231-237.
Background
Arsenic is a well-known carcinogen, which is often found in drinking-water. Epidemiologic studies have shown increased cancer risks among individuals exposed to high concentrations of arsenic in drinking-water, whereas studies of the carcinogenic effect of low doses have had inconsistent results.
Objective
Our aim was to determine if exposure to low levels of arsenic in drinking-water in Denmark is associated with an increased risk for cancer.
Methods
The study was based on a prospective Danish cohort of 57,053 persons in the Copenhagen and Aarhus areas. Cancer cases were identified in the Danish Cancer Registry, and the Danish civil registration system was used to trace and geocode residential addresses of the cohort members. We used a geographic information system to link addresses with water supply areas, then estimated individual exposure to arsenic using residential addresses back to 1970. Average exposure for the cohort ranged between 0.05 and 25.3 μg/L (mean = 1.2 μg/L). Cox’s regression models were used to analyze possible relationships between arsenic and cancer.
Results
We found no significant association between exposure to arsenic and risk for cancers of the lung, bladder, liver, kidney, prostate, or colorectum, or melanoma skin cancer; however, the risk for non-melanoma skin cancer decreased with increasing exposure (incidence rate ratio = 0.88/μg/L average exposure; 95% confidence interval, 0.84–0.94). Results adjusted for enrollment area showed no association with non-melanoma skin cancer.
Conclusions
The results indicate that exposure to low doses of arsenic might be associated with a reduced risk for skin cancer.
doi:10.1289/ehp.10623
PMCID: PMC2235208  PMID: 18288323
arsenic; cancer; cohort study; drinking-water; geographic information system
16.  Risk assessment of left ventricular systolic dysfunction in primary care: cross sectional study evaluating a range of diagnostic tests 
BMJ : British Medical Journal  2000;320(7229):220-224.
Objectives
To assess the probability of left ventricular systolic dysfunction without echocardiography in patients from general practice.
Design
Cross sectional study using multivariate regression models to examine the relation between clinical variables and left ventricular systolic dysfunction as determined by echocardiography.
Setting
Three general practices in Copenhagen.
Subjects
2158 patients aged >40 years were screened by questionnaires and case record reviews; 357 patients with past or present signs or symptoms of heart disease were identified, of whom 126 were eligible for and consented to examination.
Main outcome measures
Clinical variables that were significantly (P<0.05) related to ejection fraction ⩽0.45 and their predictive value for left ventricular systolic dysfunction.
Results
15 patients (12%) had left ventricular systolic dysfunction. The prevalence was significantly related to three questions: does the electrocardiogram have Q waves, left bundle branch block, or ST-T segment changes? (P=0.012); is resting supine heart rate greater than the simultaneous diastolic blood pressure? (P=0.002); and is plasma N-terminal atrial natriuretic peptide>0.8 nmol/l? (P=0.040)? Only one of 60 patients with a normal electrocardiogram had systolic dysfunction (2%, 95% confidence interval 0% to 9%) regardless of response to the other two questions. The risk of dysfunction was appreciable in patients with a yes answer to two or three questions (50%, 27% to 73%).
Conclusions
A normal electrocardiogram implies a low risk of left ventricular systolic dysfunction. Patients can be identified for echocardiography on the basis of an abnormal electrocardiogram combined with increased natriuretic peptide concentration or a heart rate greater than diastolic blood pressure, or both.
Key messagesEarly treatment of left ventricular systolic dysfunction reduces morbidity, but diagnosis relies on echocardiographyThis study examines methods for assessing the risk of left ventricular systolic dysfunction in patients from primary care with past or present signs or symptoms of heart diseaseRisk can be assessed by three factors: QRS or ST-T changes in the electrocardiogram; increased plasma concentration of N-terminal atrial natriuretic peptide; and tachycardia (supine resting heart rate>diastolic blood pressure)Risk of systolic dysfunction was very low in patients with normal electrocardiographic resultsRisk was high in patients who had an abnormal electrocardiogram in combination with at least one other abnormal result
PMCID: PMC27270  PMID: 10642232

Results 1-16 (16)