Cognitive resilience in clinical and preclinical Alzheimer's disease: the Association of Amyloid and Tau Burden on cognitive performance

We explored the cross-sectional relationships between β-amyloid (Aβ) and inferior temporal tau deposition (IFT Tau) on cognitive performance and whether cognitive reserve (CR) modifies these associations. We studied 156 participants classified into groups of clinically normal (CN = 133), mild cognitive impairment (MCI = 17) and Alzheimer disease (AD = 6) dementia. AMNART IQ served as a proxy of CR and cognitive performance was assessed using the MMSE. In separate linear regression models predicting MMSE, we examined the interactions of CR x global Aβ and CR x IFT tau across all participants and within the CN group alone. In the whole sample, the interaction between CR and IFT tau was significant (p < 0.003), such that higher CR participants with elevated IFT tau had better MMSE scores compared with low CR participants with similar levels of IFT tau. The interaction between CR and Aβ status did not reach significance (p = 0.093). In CN only, no cross-sectional interactions among CR, Aβ, and IFT tau were observed on MMSE. These findings imply that CR may be protective against early AD processes and enable some individuals to remain cognitively stable despite elevated tau and Aβ burden.

Routine Computer Tomography Imaging for the Detection of Recurrences in High-Risk Melanoma Patients

BACKGROUND

The use of routine CT imaging for surveillance in asymptomatic patients with cutaneous melanoma is controversial. We report our experience using a surveillance strategy that included CT imaging for a cohort of patients with high-risk melanoma.

METHODS

A total of 466 patients with high-risk cutaneous melanoma enrolled in adjuvant immunotherapy trials were followed for tumor progression by physical examination, labs, and CT imaging as defined by protocol. Evaluations were obtained at least every 6 months for year 1, every 6 months for year 2, and then annually for the remainder of the 5-year study. Time to tumor progression, sites of recurrence, and the method of relapse detection were identified.

RESULTS

The patient cohort consisted of 115 stage II patients, 328 stage III patients, and 23 patients with resected stage IV melanoma. The medium time to progression for the 225 patients who developed tumor progression was 7 months. Tumor progression was detected by patients, physician examination or routine labs, or by CT imaging alone in 27, 14, and 59% of cases respectively. Melanoma recurrences were noted to be locoregional in 36% of cases and systemic in 64% of cases. Thirty percent of patients with locoregional relapse and 75% of patients with systemic relapse were detected solely by CT imaging.

CONCLUSIONS

CT imaging alone detected the majority of sites of disease progression in our patients with high-risk cutaneous melanoma. This disease was not heralded by symptoms, physical examination, or blood work. Although the benefit of the early detection of advanced melanoma is unknown, this experience is relevant because of the rapid development and availability of potentially curative immunotherapies.

Cognitive reserve and cortical thickness in preclinical Alzheimer's disease

This study examined whether cognitive reserve (CR) alters the relationship between magnetic resonance imaging (MRI) measures of cortical thickness and risk of progression from normal cognition to the onset of clinical symptoms associated with mild cognitive impairment (MCI). The analyses included 232 participants from the BIOCARD study. Participants were cognitively normal and largely middle aged (M age = 56.5) at their baseline MRI scan. After an average of 11.8 years of longitudinal follow-up, 48 have developed clinical symptoms of MCI or dementia (M time from baseline to clinical symptom onset = 7.0 years). Mean thickness was measured over eight 'AD vulnerable' cortical regions, and cognitive reserve was indexed by a composite score consisting of years of education, reading, and vocabulary measures. Using Cox regression models, CR and cortical thickness were each independently associated with risk of clinical symptom onset within 7 years of baseline, suggesting that the neuronal injury occurring proximal to symptom onset has a direct association with clinical outcomes, regardless of CR. In contrast, there was a significant interaction between CR and mean cortical thickness for risk of progression more than 7 years from baseline, suggesting that individuals with high CR are better able to compensate for cortical thinning that is beginning to occur at the very earliest phase of AD.

Optimization of left adrenal vein sampling in primary aldosteronism: Coping with asymmetrical cortisol secretion

We evaluated the influence of catheter sampling position and size on left adrenal venous sampling (AVS) in patients with primary aldosteronism (PA) and analyzed their relationship to cortisol secretion. This retrospective study included 111 patients with a diagnosis of primary aldosteronism who underwent tetracosactide-stimulated AVS. Left AVS was obtained from two catheter positions - the central adrenal vein (CAV) and the common trunk. For common trunk sampling, 5-French catheters were used in 51 patients, and microcatheters were used in 60 patients. Autonomous cortisol secretion was evaluated with a low-dose dexamethasone suppression test in 87 patients. The adrenal/inferior vena cava cortisol concentration ratio [selectivity index (SI)] was significantly lower in samples from the left common trunk than those of the left CAV and right adrenal veins, but this difference was reduced when a microcatheter was used for common trunk sampling. Sample dilution in the common trunk of the left adrenal vein can be decreased by limiting sampling speed with the use of a microcatheter. Meanwhile, there was no significant difference in SI between the left CAV and right adrenal veins. Laterality, determined according to aldosterone/cortisol ratio (A/C ratio) based criteria, showed good reproducibility regardless of sampling position, unlike the absolute aldosterone value based criteria. However, in 11 cases with autonomous cortisol co-secretion, the cortisol hypersecreting side tended to be underestimated when using A/C ratio based criteria. Left CAV sampling enables symmetrical sampling, and may be essential when using absolute aldosterone value based criteria in cases where symmetrical cortisol secretion is uncertain.

Screening for Celiac Disease: US Preventive Services Task Force Recommendation Statement

IMPORTANCE

Celiac disease is caused by an immune response in persons who are genetically susceptible to dietary gluten, a protein complex found in wheat, rye, and barley. Ingestion of gluten by persons with celiac disease causes immune-mediated inflammatory damage to the small intestine.

OBJECTIVE

To issue a new US Preventive Services Task Force (USPSTF) recommendation on screening for celiac disease.

EVIDENCE REVIEW

The USPSTF reviewed the evidence on the accuracy of screening in asymptomatic adults, adolescents, and children; the potential benefits and harms of screening vs not screening and targeted vs universal screening; and the benefits and harms of treatment of screen-detected celiac disease. The USPSTF also reviewed contextual information on the prevalence of celiac disease among patients without obvious symptoms and the natural history of subclinical celiac disease.

FINDINGS

The USPSTF found inadequate evidence on the accuracy of screening for celiac disease, the potential benefits and harms of screening vs not screening or targeted vs universal screening, and the potential benefits and harms of treatment of screen-detected celiac disease.

CONCLUSIONS AND RECOMMENDATION

The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of screening for celiac disease in asymptomatic persons. (I statement).

Screening for Celiac Disease: Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Silent or subclinical celiac disease may result in potentially avoidable adverse health consequences.

OBJECTIVE

To review the evidence on benefits and harms of screening for celiac disease in asymptomatic adults, adolescents, and children 3 years and older for the US Preventive Services Task Force.

DATA SOURCES

Ovid MEDLINE, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews, searched to June 14, 2016.

STUDY SELECTION

Randomized clinical trials and cohort or case-control studies on clinical benefits and harms of screening vs no screening for celiac disease or treatment vs no treatment for screen-detected celiac disease; studies on diagnostic accuracy of serologic tests for celiac disease.

DATA EXTRACTION AND SYNTHESIS

One investigator abstracted data, a second checked data for accuracy, and 2 investigators independently assessed study quality using predefined criteria.

MAIN OUTCOMES AND MEASURES

Cancer incidence, gastrointestinal outcomes, psychological outcomes, child growth outcomes, health outcomes resulting from nutritional deficiencies, quality of life, mortality, and harms of screening. No meta-analytic pooling was done.

RESULTS

One systematic review and 3 primary studies met inclusion criteria. No trials of screening for celiac disease were identified. One recent, good-quality systematic review of 56 original studies and 12 previous systematic reviews (sample sizes of primary studies ranging from 62 to more than 12 000 participants) found IgA tissue transglutaminase was associated with high accuracy (sensitivity and specificity both >90%) for diagnosing celiac disease. IgA endomysial antibodies tests were associated with high specificity. Only 2 studies of serologic tests for celiac disease involving 62 and 158 patients were conducted in asymptomatic populations and reported lower sensitivity (57% and 71%). One fair-quality, small (n = 40) Finnish treatment trial of asymptomatic adults with screen-detected celiac disease based on positive serologic findings found initiation of a gluten-free diet associated with small improvement in gastrointestinal symptoms compared with no gluten-free diet (difference less than 1 point on a scale of 1 to 7) at 1 year, with no differences on most measures of quality of life. No withdrawals due to adverse events occurred during the trial; no other harms were reported. No studies were identified that addressed the other outcomes.

CONCLUSIONS AND RELEVANCE

Although some evidence was found regarding diagnostic accuracy of tests for celiac disease, little or no evidence was identified to inform most of the key questions related to benefits and harms of screening for celiac disease in asymptomatic individuals. More research is needed to understand the effectiveness of screening and treatment for celiac disease, accuracy of screening tests in asymptomatic persons, and optimal screening strategies.

Establishing a Timeline to Discontinue Routine Testing of Asymptomatic Pregnant Women for Zika Virus Infection - American Samoa, 2016-2017

The first patients with laboratory-confirmed cases of Zika virus disease in American Samoa had symptom onset in January 2016 (1). In response, the American Samoa Department of Health (ASDoH) implemented mosquito control measures (1), strategies to protect pregnant women (1), syndromic surveillance based on electronic health record (EHR) reports (1), Zika virus testing of persons with one or more signs or symptoms of Zika virus disease (fever, rash, arthralgia, or conjunctivitis) (1-3), and routine testing of all asymptomatic pregnant women in accordance with CDC guidance (2,3)^. All collected blood and urine specimens were shipped to the Hawaii Department of Health Laboratory for Zika virus testing and to CDC for confirmatory testing. Early in the response, collection and testing of specimens from pregnant women was prioritized over the collection from symptomatic nonpregnant patients because of limited testing and shipping capacity. The weekly numbers of suspected Zika virus disease cases declined from an average of six per week in January-February 2016 to one per week in May 2016. By August, the EHR-based syndromic surveillance (1) indicated a return to pre-outbreak levels. The last Zika virus disease case detected by real-time, reverse transcription-polymerase chain reaction (rRT-PCR) occurred in a patient who had symptom onset on June 19, 2016. In August 2016, ASDoH requested CDC support in assessing whether local transmission had been reduced or interrupted and in proposing a timeline for discontinuation of routine testing of asymptomatic pregnant women. An end date (October 15, 2016) was determined for active mosquito-borne transmission of Zika virus and a timeline was developed for discontinuation of routine screening of asymptomatic pregnant women in American Samoa (conception after December 10, 2016, with permissive testing for asymptomatic women who conceive through April 15, 2017).

Measures of bronchodilator response of FEV1, FVC and SVC in a Swedish general population sample aged 50-64 years, the SCAPIS Pilot Study

BACKGROUND

Data are lacking from general population studies on how to define changes in lung function after bronchodilation. This study aimed to analyze different measures of bronchodilator response of forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC) and slow vital capacity (SVC).

MATERIALS AND METHODS

Data were derived from the Swedish Cardiopulmonary Bioimage Study (SCAPIS) Pilot study. This analysis comprised 1,050 participants aged 50-64 years from the general population. Participants were investigated using a questionnaire, and FEV1, FVC and SVC were recorded before and 15 minutes after inhalation of 400 µg of salbutamol. A bronchodilator response was defined as the relative change from baseline value expressed as the difference in units of percent predicted normal. Predictors of bronchodilator responses were assessed using multiple linear regression models. Airway obstruction was defined as FEV1/FVC ratio below lower limit of normal (LLN) before bronchodilation, and COPD was defined as an FEV1/FVC ratio below LLN after bronchodilation. Physician-diagnosed asthma was defined as an affirmative answer to "Have you ever had asthma diagnosed by a physician?". Asymptomatic never-smokers were defined as those not reporting physician-diagnosed asthma, physician-diagnosed COPD or emphysema, current wheeze or chronic bronchitis and being a lifelong never-smoker.

RESULTS

Among all subjects, the greatest bronchodilator responses (FEV1, FVC and SVC) were found in subjects with asthma or COPD. The upper 95th percentile of bronchodilator responses in asymptomatic never-smokers was 8.7% for FEV1, 4.2% for FVC and 5.0% for SVC. The bronchodilator responses were similar between men and women. In a multiple linear regression model comprising all asymptomatic never-smokers, the bronchodilator response of FEV1 was significantly associated with airway obstruction and height.

CONCLUSION

When the bronchodilator response in asymptomatic never-smokers is reported as the difference in units of predicted normal, significant reversibility of FEV1, FVC and SVC to bronchodilators is ~9%, 4% and 5%, respectively.

Alcohol and tea consumption are associated with asymptomatic erosive esophagitis in Taiwanese men

Objective

Asymptomatic erosive esophagitis (AEE) is commonly found in men, and might be a risk factor of developing esophageal adenocarcinoma. We aimed to determine if specific dietary habits increase the risk of AEE in asymptomatic Taiwanese men.

Methods

We recruited male adults undergoing upper gastrointestinal endoscopy for health check. We excluded subjects with reflux symptoms, or taking anti-reflux medications or drugs that potentially impair lower esophageal sphincter function or cause mucosal injury. The frequency of consuming reflux-provoking diets including alcohol, tea, coffee, tomato/citric juice, chocolate, sweet food, and spicy food was assessed. The erosive esophagitis was diagnosed based on the Los Angeles Classification after endoscopy. Frequent consumption of a specific diet was defined as ≥4 days/week of consuming that diet.

Results

A total of 1256 participants were recruited. After excluding 424 ineligible subjects, AEE was identified in 180 (22%) among 832 asymptomatic subjects. The risk of AEE increased with the number of days per week of consuming alcohol or tea: nondrinkers (19%, 17%), occasional drinkers (<1 day/week; 19%, 15%), regular drinkers (1–3 days/week; 26%, 21%), frequent drinkers (4–6 days/week; 32%, 22%), and daily drinkers (42%, 28%), respectively (trend test P < 0.001 for both). Multivariate analysis showed that hiatus hernia (adjusted odds ratio (aOR) 5.0, 95% confidence interval (CI) 2.6–9.6), drinking alcohol ≥4 days/week (aOR 2.3, 95% CI 1.3–4.0), and drinking tea ≥4 days/week (aOR 1.6, 95% CI 1.1–2.3) are independent risk factors of AEE. The risk of AEE was 3.8 times greater for those drinking both alcohol and tea ≥4 days/week than the non-drinkers.

Conclusions

Frequent alcohol and tea consumption increased the risk of AEE in Taiwanese men.

[Asymptomatic skull base metastases: clinical course and therapeutic alternatives]

INTRODUCTION

Skull base metastases (SBM) are an infrequent and late type of cancer progression that are associated to poor prognosis. Its clinical manifestations may be grouped in five clinical syndromes and radiotherapy is its more frequent treatment. Because of the improvement in imaging tests and the close follow up of cancer patients, SBM can be diagnosed incidentally. In this group the best option of treatment has not been established.

AIM

To analyze the clinical features and outcomes of patients with SBM diagnosed incidentally.

PATIENTS AND METHODS

Between January 2012 and December 2015, 31 patients with diagnoses of SBM from solid primary tumor were reviewed.

RESULTS

SBM were diagnosed due to skull base syndromes (n = 24) or incidentally (n = 7). Symptomatic patients were treated with radiotherapy. Patients diagnosed incidentally remained without symptoms of craneal base involvement during the follow up, although they frequently had other types of intracranial progression. A statistically significant difference in survival was observed between symptomatic and asymptomatic patients (p = 0.001).

CONCLUSIONS

The incidentally diagnosed SBM were frequently associated to other types of intracranial progression, limiting the options of treatment.

Evaluation of liver enzyme levels and identification of asymptomatic liver disease patients in primary care

The evaluation of serum liver enzyme levels is the most used surrogate marker of liver injury in clinical practice. The prevalence and association of abnormal enzyme values with hepatitis B virus (HBV) and hepatitis C virus (HCV) infections, and with other major causes of liver damage (obesity, diabetes, dyslipidemia, and alcohol abuse) were evaluated in individuals attending the surgeries of 14 general practitioners (GPs) working in Messina. Alanine-amino-transferase, aspartate-amino-transferase, and gamma-glutamyl-transpeptidase measurements were measured in 7816 individuals consecutively attending the GP surgeries between January 1, 2011 and June 30, 2012. Five-thousand-eight-hundred-six subjects (74.3 %) had the tests performed, and 1189 of them (20.5 %) showed increased liver enzyme levels. Sixty-nine of these 1189 individuals (5.8 %) were HCV positive and 12 HBV positive (1 %), 755 (63.5 %) were overweight or obese, 288 (24.2 %) had diabetes, and 351 (29.5 %) had dyslipidemia; 262 (22 %) drank >2 alcoholic units/day. Overall, 57 % of individuals with abnormal liver enzymes had multiple possible causes of liver disease, 28 % one cause, and 15 % no apparent cause. In conclusion, this study shows that 1/5 of individuals attending GP surgeries have altered liver biochemistry and that overweight and metabolic disorders have become the major causes of liver damage even in South Italy, where HBV and HCV were endemic in the past century. Notably, many HCV and HBV patients are still unaware of their infected status, and GPs are essential for their timely identification.

Myocardial performance index in active and inactive paediatric systemic lupus erythematosus

OBJECTIVES

To evaluate cardiac structure and function in paediatric SLE patients without clinical evidence of cardiovascular disease in active and inactive diseases.

METHODS

Patients aged ≤20 years who fulfilled the diagnostic criteria of active SLE underwent transthoracic echocardiography to evaluate cardiac structure and function, and were then followed up echocardiographically every 3-4 months until SLE disease was inactive. Patients with heart failure, myocarditis, pericarditis, endocarditis, coronary artery disease, or abnormal structural heart disease were excluded.

RESULTS

Twenty-six active SLE patients, mean age 13.2±3.3 years, of whom 20 were female (77%), were enrolled. Most patients had cardiac abnormalities especially LV global dysfunction assessed by left ventricular myocardial performance index (LV MPI). LV MPI by conventional method, by tissue Doppler imaging (TDI) at medial and lateral mitral valve annulus were significantly decreased when compared to LV MPI in patients with inactive disease (0.44±0.14 vs. 0.30±0.05, 0.52±0.09 vs. 0.36±0.04, and 0.51±0.09 vs. 0.35±0.05, p<0.001). Using receiver operating characteristic, LV MPI cut-off at 0.37, 0.40, and 0.40 by conventional, medial TDI, lateral TDI had sensitivity and specificity of 90% and 84%, 90% and 96%, 90% and100%, respectively.

CONCLUSIONS

Left ventricular global dysfunction was found to be common in paediatric patients with active SLE. LV MPI by TDI might be useful to diagnose active SLE in paediatric patients.

Left atrial phasic function and heart rate variability in asymptomatic diabetic patients

AIMS

We evaluated left atrial (LA) phasic function and heart rate variability (HRV) in asymptomatic diabetic patients, and the relationship between HRV indices and LA phasic function assessed by volumes and speckle tracking imaging.

METHOD

This cross-sectional study included 55 asymptomatic patients with type 2 diabetes and 50 healthy controls without cardiovascular risk factors. All study subjects underwent laboratory analyses, complete two-dimensional echocardiography examination (2DE) and 24-h Holter monitoring.

RESULTS

Maximum, minimum LA and pre-A LA volumes and volume indexes are significantly higher in diabetic patients. Total and passive LA emptying fractions (EF), representing the LA reservoir and conduit function, are significantly lower in diabetic subjects. Active LA EF, the parameter of the LA booster pump function, is compensatory increased in diabetic patients. Similar results were obtained by 2DE strain analysis. Cardiac autonomic function, assessed by HRV, is significantly deteriorated in diabetic patients. Time and frequency-domain HRV measures are significantly lower in diabetic subjects than in controls. HbA1c, LV mass index and HRV are associated with total LA EF and longitudinal LA strain independently of age, body mass index and LV diastolic function in the whole study population.

CONCLUSIONS

LA phasic function and cardiac autonomic nervous system assessed by HRV are impacted by diabetes. HbA1c and HRV are independently associated with LA reservoir function evaluated by volumetric and strain methods in the whole study population. This study emphasizes the importance of determination of LA function and HRV as important markers of preclinical cardiac damage and autonomic function impairment in diabetic patients.

Renal function and carotid atherosclerosis in adults with no known kidney disease

BACKGROUND AND AIMS

A high prevalence of atherosclerotic lesions characterizes patients with chronic kidney disease, though there is little data on the relationship between kidney function and atherosclerotic changes in the healthy population or in people with no known renal impairment. The aim of our study was to analyze, in a comprehensive general population with no known kidney disease, the relationship between renal function and subclinical carotid atherosclerotic damage.

METHODS AND RESULTS

A general real-life population of 611 participants (233 males and 378 females; age ≥18 years) with no known kidney failure was selected for the study. The glomerular filtration rate (GFR) was estimated according to the CKD-EPI equation. Carotid intima-media thickness (c-IMT) and plaques were assessed by duplex Doppler ultrasonography of the carotid vessels. The main laboratory and metabolic parameters were evaluated in all participants. When we divided the overall study population into tertiles according to GFR values (I tertile <85; II tertile: 85-99; III tertile >99 ml/min/1.73 m²), the c-IMT mean values and the prevalence of carotid plaques decreased with the increasing tertile of GFR. On univariate analysis, c-IMT was significantly correlated with eGFR (r = -0.33; p < 0.001), serum creatinine (r = 0.17; p < 0.001), and other variables such as age, systolic blood pressure, waist circumference, fasting or random glycemia, and glycated hemoglobin (HbA₁c). On multiple regression analysis, serum creatinine was associated with c-IMT (β = 0.069; p = 0.017), independent of other covariates.

CONCLUSION

Our study seems to suggest the importance of early identification of people with near normal or mildly decreased renal function due to its association with carotid atherosclerosis.

Risk factors for silent myocardial ischemia in patients with well-controlled essential hypertension

Silent myocardial ischemia (SMI) is frequently observed in patients with essential hypertension (EH). The major risk factor for SMI is uncontrolled blood pressure (BP), but SMI is also observed in patients with well-controlled BP. To evaluate the prevalence of SMI and the factors associated with SMI in EH patients with well-controlled BP. The medical records of 859 EH patients who underwent simultaneous 24-h ambulatory blood pressure monitoring (ABPM) and 24-h ambulatory electrocardiogram recording (AECG) were retrospectively evaluated. Each SMI episode was characterized by: (a) ST segment depression ≥0.5 mm; (b) duration of ST segment depression >60 s; and (c) reversibility of the ST segment depression. Overall 126 EH patients (14.7 %) had at least one episode of SMI. The SMI events were more frequent among patients with poorly controlled compared to those with well-controlled BP [86/479 (17.95 %) vs. 40/380 (10.52 %), p < 0.01]. Among EH patients with well-controlled BP, current and past smoking as well as the presence of an additional metabolic syndrome (MetS) constitutive element (obesity, impaired fasting glucose level or dyslipidemia) were significantly associated with the occurrence of SMI. In all EH patients with well-controlled BP and AECG evidence of SMI, there were one or more coronary artery stenotic lesions greater than 50 % found at coronary angiography. In EH patients who are current smokers, or have one or more additional components of a MetS there is markedly reduced benefit associated with good BP control with regard to the occurrence of myocardial ischemia: in this patient category, an AECG may help detect this condition.

Early and late change on the preclinical Alzheimer's cognitive composite in clinically normal older individuals with elevated amyloid β

INTRODUCTION

Sensitive detection of cognitive decline over the course of preclinical Alzheimer's disease is critical as the field moves toward secondary prevention trials.

METHODS

We examined amyloid β (Aβ)-related change in several variations of the preclinical Alzheimer cognitive composite (PACC) and each individual PACC component in clinically normal (CN) older participants in the Harvard Aging Brain Study. We then examined the PACC variations in the Alzheimer's Disease Cooperative Study Prevention Instrument Study as a replication cohort.

RESULTS

Aβ+ CN individuals demonstrated longitudinal decline on all individual PACC components and all PACC variations. Aβ group differences emerged earlier when Free and Cued Selective Reminding Test Free Recall was included in the PACC. PACC decline was associated with Clinical Dementia Rating progression.

DISCUSSION

This independent data set and a replication cohort confirm the ability of the PACC to capture both early and late cognitive decline during the preclinical stages of Alzheimer's disease, which may prove advantageous in the prevention trial design.

The natural killer cell response to West Nile virus in young and old individuals with or without a prior history of infection

West Nile virus (WNV) typically leads to asymptomatic infection but can cause severe neuroinvasive disease or death, particularly in the elderly. Innate NK cells play a critical role in antiviral defenses, yet their role in human WNV infection is poorly defined. Here we demonstrate that NK cells mount a robust, polyfunctional response to WNV characterized by cytolytic activity, cytokine and chemokine secretion. This is associated with downregulation of activating NK cell receptors and upregulation of NK cell activating ligands for NKG2D. The NK cell response did not differ between young and old WNV-naïve subjects, but a history of symptomatic infection is associated with more IFN-γ producing NK cell subsets and a significant decline in a specific NK cell subset. This NK repertoire skewing could either contribute to or follow heightened immune pathogenesis from WNV infection, and suggests that NK cells could play an important role in WNV infection in humans.

Endomyocardial involvement in asymptomatic sub-Saharan immigrants with helminth-related eosinophilia

Background

Among immigrants of sub-Saharan origin, parasitic infection is the leading cause of eosinophilia, which is generally interpreted as a defense mechanism. A side effect of the inflammatory mediators released by eosinophils is damage to host organs, especially the heart. The main objectives of this study were to i) assess cardiac involvement in asymptomatic sub-Saharan immigrants with eosinophilia, ii) relate the presence of lesions with the degree of eosinophilia, and iii) study the relationship between cardiac involvement and the type of causative parasite.

Methodology/Principle findings

In total, the study included 50 black immigrants (37 patients and 13 controls) from sub-Saharan Africa. In all subjects, heart structure and function were evaluated in a blinded manner using Sonos 5500 echocardiographic equipment. The findings were classified and described according to established criteria. The diagnostic criteria for helminthosis were those reported in the literature. Serum eosinophil-derived neurotoxin levels were measured using enzyme-linked immunosorbent assay. A significant association was found between the presence of eosinophilia and structural alterations (mitral valve thickening). However, the lack of an association between the degree of eosinophilia and heart valve disease and the absence of valve involvement in some patients with eosinophilia suggest the role of other factors in the appearance of endocardial lesions. There was also no association between the type of helminth and valve involvement.

Conclusions

We, therefore, suggest that transthoracic echocardiography be performed in every sub-Saharan individual with eosinophilia in order to rule out early heart valve lesions.

Endomyocardial fibrosis is characterized by fibrosis of the apical endocardium of the right ventricle, left ventricle, or both. Epidemiological studies of endomyocardial fibrosis indicate a predominance in tropical regions, with young people and men being affected predominantly. Little is known about the natural history and pathogenic factors of this condition. One of the most important factors is the presence of eosinophilia, which is mainly related to helminth infections. The aim of the study was to evaluate cardiac involvement in patients with absolute eosinophilia. We performed an echocardiographic study in asymptomatic sub-Saharan immigrants with eosinophilia and compared them with a group of control patients from the same region and of the same age. Our results suggest that eosinophilia associated with helminth infection (regardless of the causative microorganism) contributes to the asymptomatic phases of endomyocardial involvement. Treatment of these infections is simple, effective, and economical. Therefore, we suggest that all immigrant patients with eosinophilia undergo etiologic study and causal treatment as well as transthoracic echocardiography in order to rule out early damage.

Blastocystis subtyping and its association with intestinal parasites in children from different geographical regions of Colombia

Blastocystis is a common enteric protist colonizing probably more than 1 billion people with a large variety of non-human hosts. Remarkable genetic diversity has been observed, leading to the subdivision of the genus into multiple subtypes (ST), some of which are exclusively found in non-human hosts. The aim of this study was to determine the distribution of Blastocystis STs/18S alleles in symptomatic (abdominal pain, anal pruritus, diarrhea, headache, nauseas and/or vomit) and asymptomatic children from nine geographical regions of Colombia. A total of 2026 fecal samples were collected as part of a national survey to estimate the frequency of intestinal parasites in children. A set of 256 samples that were Blastocystis positive was finally selected. The samples were submitted to DNA extraction, Real Time PCR and sequencing using Blastocystis-specific primers targeting the small subunit rRNA gene for ST identification. DNA of Ascaris lumbricoides (16.4%), Trichuris trichiura (8.2%), hookworms (Necator americanus/Ancylostoma duodenale) (7.3%), Giardia duodenalis (23.1%), Entamoeba complex (82%), Entamoeba coli (55%), Hymenolepis nana (0.8%), Endolimax nana (33.2%) and Neobalantidium coli (2.7%) was detected in the Blastocystis-positive samples. We detected ST1 (21.4%), ST2 (19.5%), ST3 (55.5%), ST4 (0.8%), ST6 (2%) and ST7 (0.8%); alleles 1, 2, 4, 81, 82 and 83 for ST1; alleles 9, 11, 12, 15, 67, 71 and 73 for ST2; alleles 34, 36, 38, 45, 49, 55, 134 and 128 for ST3; allele 42 for ST4; allele 122 for ST6, and allele 142 for ST7. Further studies implementing high-resolution molecular markers are necessary to understand the dynamics of Blastocystis transmission and the role of this Stramenopila in health and disease.

Magnetic resonance imaging for cerebral lesions during minimal invasive mitral valve surgery: study protocol for a randomized controlled trial

BACKGROUND

Recent data have highlighted a higher rate of neurological injuries in minimal invasive mitral valve surgery (MIMVS) compared with the standard sternotomy approach; therefore, the role of specific clamping techniques and perfusion strategies on the occurrence of this complication is a matter of discussion in the medical literature. The purpose of this trial is to prospectively evaluate major, minor and silent neurological events in patients undergoing right mini-thoracotomy mitral valve surgery using retrograde perfusion and an endoaortic clamp or a transthoracic clamp.

METHODS/DESIGN

A prospective, blinded, randomized controlled study on the rate of neurological embolizations during MIMVS started at the University of Turin in June 2014. Major, minor and silent neurological events are being investigated through standard neurological evaluation and magnetic resonance imaging assessment. The magnetic resonance imaging protocol includes conventional sequences for the morphological and quantitative assessment and nonconventional sequences for the white matter microstructural evaluation. Imaging studies are performed before surgery as baseline assessment and on the third postoperative day and, in patients who develop postoperative ischemic lesions, after 6 months.

DISCUSSION

Despite recent concerns raised about the endoaortic setting with retrograde perfusion, we expect to show equivalence in terms of neurological events of this technique compared with the transthoracic clamp in a selected cohort of patients. With the first results expected in December 2016 the findings would be of help in confirming the efficacy and safety of MIMVS.

TRIAL REGISTRATION

ClinicalTrials.gov, Identifier: NCT02818166 . Registered on 8 February 2016 - trial retrospectively registered.

Relation of Functional Status to Risk of Development of Atrial Fibrillation

Identifying patients at risk is now important as there are demonstrable ways to alter disease progression which could potentially prevent atrial fibrillation (AF) and its complications. We sought whether impaired functional capacity was associated with risk of AF, independent of myocardial dysfunction. In this community-based study, asymptomatic participants aged ≥65 years were recruited if they had ≥1 risk factor (e.g., hypertension, diabetes mellitus, and obesity). Participants underwent baseline echocardiography (including measurement of myocardial mechanics) and six-minute walk test. The CHARGE-AF score was used to calculate 5-year risk of developing AF. Receiver operating characteristic curves were used to assess for independent risk factors for AF. A total of 607 patients (age 71 ± 5 years, men 47%) were studied at baseline and followed for at least 6 months. Patients in the higher AF risk groups were older and had increased rates of hypertension, diabetes mellitus, and ischemic heart disease (p <0.05). Greater AF risk was associated with lower exercise capacity, independent of lower mean global longitudinal strain, global circumferential strain, greater mean E/e' ratio, indexed left atrial volume and LV mass. Multivariate linear regression confirmed association of LV and functional capacity parameters with AF risk. Although functional capacity is impaired in AF, this association precedes the onset of AF. In conclusion, poor functional status is associated with AF risk, independent of LV function.

Asymptomatic leishmaniasis in kala-azar endemic areas of Malda district, West Bengal, India

Asymptomatic leishmaniasis may drive the epidemic and an important challenge to reach the goal of joint Visceral Leishmaniasis (VL) elimination initiative taken by three Asian countries. The role of these asymptomatic carriers in disease transmission, prognosis at individual level and rate of transformation to symptomatic VL/Post Kala-azar Dermal Leishmaniasis (PKDL) needs to be evaluated. Asymptomatic cases were diagnosed by active mass survey in eight tribal villages by detecting antileishmanial antibody using rK39 based rapid diagnostic kits and followed up for three years to observe the pattern of sero-conversion and disease transformation. Out of 2890 total population, 2603 were screened. Antileishmanial antibody was detected in 185 individuals of them 96 had a history of VL/PKDL and 89 without such history. Seventy nine such individuals were classified as asymptomatic leishmaniasis and ten as active VL with a ratio of 7.9:1. Out of 79 asymptomatic cases 2 were lost to follow up as they moved to other places. Amongst asymptomatically infected persons, disease transformation in 8/77 (10.39%) and sero-conversion in 62/77 (80.52%) cases were noted. Seven (9.09%) remained sero-positive even after three years. Progression to clinical disease among asymptomatic individuals was taking place at any time up to three years after the baseline survey. If there are no VL /PKDL cases for two or more years, it does not mean that the area is free from leishmaniasis as symptomatic VL or PKDL may appear even after three years, if there are such asymptomatic cases. So, asymptomatic infected individuals need much attention for VL elimination programme that has been initiated by three adjoining endemic countries.

A total of 79 asymptomatic VL cases were detected from two kala-azar endemic blocks of Malda districts of West Bengal by active mass screening. Follow study of the asymptomatic cases revealed that 10.39% cases transformed into disease and 9.09% cases remained as sero-positive even after three years. So progression to clinical disease among asymptomatic individuals was taking place at any time up to three years after the baseline survey. Therefore, in a given period if there are no cases of VL/PKDL for two or more years, it does not mean that the area is free from leishmaniasis as symptomatic VL or PKDL may appear even after three years, if there are such asymptomatic cases. So, asymptomatic infected individuals need much attention for VL elimination programme that has been initiated by three adjoining endemic countries.