Detection of group A streptococcus in children with confirmed viral pharyngitis and antiviral host response.

Our aim was to study the detection of group A streptococcus (GAS) with different diagnostic methods in paediatric pharyngitis patients with and without a confirmed viral infection. In this prospective observational study, throat swabs and blood samples were collected from children (age 1-16 years) presenting to the emergency department with febrile pharyngitis. A confirmed viral infection was defined as a positive virus diagnostic test (nucleic acid amplification test [NAAT] and/or serology) together with an antiviral immune response of the host demonstrated by elevated (≥ 175 µg/L) myxovirus resistance protein A (MxA) blood concentration. Testing for GAS was performed by a throat culture, by 2 rapid antigen detection tests (StrepTop and mariPOC) and by 2 NAATs (Simplexa and Illumigene). Altogether, 83 children were recruited of whom 48 had samples available for GAS testing. Confirmed viral infection was diagnosed in 30/48 (63%) children with febrile pharyngitis. Enteroviruses 11/30 (37%), adenoviruses 9/30 (30%) and rhinoviruses 9/30 (30%) were the most common viruses detected. GAS was detected by throat culture in 5/30 (17%) with and in 6/18 (33%) patients without a confirmed viral infection. Respectively, GAS was detected in 4/30 (13%) and 6/18 (33%) by StrepTop, 13/30 (43%) and 10/18 (56%) by mariPOC, 6/30 (20%) and 9/18 (50%) by Simplexa, and 5/30 (17%) and 6/18 (30%) patients by Illumigene. CONCLUSION: GAS was frequently detected also in paediatric pharyngitis patients with a confirmed viral infection. The presence of antiviral host response and increased GAS detection by sensitive methods suggest incidental throat carriage of GAS in viral pharyngitis. WHAT IS KNOWN: •The frequency and significance of GAS-virus co-detection are poorly characterised in children with pharyngitis. •Detection of a virus and the antiviral host response likely indicates symptomatic infection. WHAT IS NEW: •Group A streptococcus (GAS) was detected in 17-43% of the children with confirmed viral pharyngitis depending on the GAS diagnostic method. •Our results emphasize the risk of detecting and treating incidental pharyngeal carriage of GAS in children with viral pharyngitis.

Association of Ideal Cardiovascular Health in Youth with Cancer Risk in Adulthood: A Cardiovascular Risk in Young Finns Study.

BACKGROUND: Lifestyle factors may affect cancer risk. This study aimed to identify whether the American Heart Association ideal cardiovascular health (ICH) score and its individual variables in youth are associated with subsequent cancer incidence. METHODS: This study comprised participants of the Cardiovascular Risk in Young Finns Study free of cancer at the analysis baseline in 1986 (n = 1,873). The baseline age was 12 to 24 years, and the follow-up occurred between 1986 and 2018. RESULTS: Among 1,873 participants (mean age 17.3 ± 4.1 years; 53.4% females at baseline), 72 incident cancer cases occurred during the follow-up (mean follow-up time 31.4 ± 3.4 years). Baseline ICH score was not associated with future cancer risk (HR, 0.96; 95% confidence interval, 0.78-1.12 per 1-point increment). Of individual ICH score variables, ideal physical activity (PA) was inversely associated with cancer incidence [age- and sex-adjusted HR, 0.45 (0.23-0.88) per 1-category change (nonideal/ideal)] and remained significant in the multivariable-adjusted model, including body mass index, smoking, diet, and socioeconomic status. A continuous PA index at ages 9 to 24 years and moderate-to-vigorous PA in youth were also related to decreased cancer incidence (P < 0.05). Body mass index, smoking, diet, total cholesterol, glucose, and blood pressure were not related to cancer risk. Of the dietary components, meat consumption was associated with cancer incidence (P = 0.023). CONCLUSIONS: These findings indicate that higher PA levels in youth are associated with a reduced subsequent cancer incidence, whereas the American Heart Association's ICH score in youth does not. IMPACT: This finding supports efforts to promote a healthy lifestyle and encourages PA during childhood, yielding a subsequent healthier life.

Different role of CD73 in leukocyte trafficking via blood and lymph vessels.

CD73 is involved in the extracellular ATP metabolism by dephosphorylating extracellular AMP to adenosine and thus regulating permeability of the blood vessels and leukocyte traffic into the tissues. It is also present on lymphatic vessels where its distribution and function have not been characterized. We found that CD73 is expressed on a subpopulation of afferent lymph vessels but is absent on efferent lymphatics, unlike LYVE-1 and podoplanin, which are expressed on both types of lymphatics. The extracellular nucleotide metabolism on lymphatic endothelium differs from that on blood vessel endothelium as lymphatic endothelium has lower NTPDase and higher ecto-5'-nucleotidase/CD73 activity than blood vascular endothelium. In knockout mice, the lack of CD73 on lymphocytes decreases migration of lymphocytes to the draining lymph nodes more than 50% while CD73-deficient lymph vessels mediate lymphocyte trafficking as efficiently as the wild-type lymphatics. Thus, although endothelial CD73 is important for permeability and leukocyte extravasation in blood vessels, it does not have a role in these functions on lymphatics. Instead, lymphocyte CD73 is intimately involved in lymphocyte migration via afferent lymphatic vessels.

Altered purinergic signaling in CD73-deficient mice inhibits tumor progression.

CD73/ecto-5'-nucleotidase dephosphorylates extracellular AMP into adenosine, and it is a key enzyme in the regulation of adenosinergic signaling. The contribution of host CD73 to tumor growth and anti-tumor immunity has not been studied. Here, we show that under physiological conditions CD73-deficient mice had significantly elevated ATPase and ADPase activities in LN T cells. In a melanoma model, the growth of primary tumors and formation of metastasis were significantly attenuated in mice lacking CD73. Among tumor-infiltrating leukocytes there were fewer Tregs and mannose receptor-positive macrophages, and increased IFN-γ and NOS2 mRNA production in CD73-deficient mice. Treatment of tumor-bearing animals with soluble apyrase, an enzyme hydrolyzing ATP and ADP, significantly inhibited tumor growth and accumulation of intratumoral Tregs and mannose receptor-positive macrophages in the WT C57BL/6 mice but not in the CD73-deficient mice. Pharmacological inhibition of CD73 with α,ß-methylene-adenosine-5'-diphosphate in WT mice retarded tumor progression similarly to the genetic deletion of CD73. Together these data show that increased pericellular ATP degradation in the absence of CD73 activity in the host cells is a novel mechanism controlling anti-tumor immunity and tumor progression, and that the purinergic balance can be manipulated therapeutically to inhibit tumor growth.

What puts the 'yuck' in the yuck factor?

The advances in biotechnology have given rise to a discussion concerning the strong emotional reaction expressed by the public towards biotechnological innovations. This reaction has been named the 'Yuck-factor' by several theorists of bioethics. Leon Kass, the former chairman of the President's council on bioethics, has appraised this public reaction as 'an emotional expression of deep wisdom, beyond reason's power fully to articulate it'.(1) Similar arguments have been forwarded by the Catholic Church, several Protestant denominations and the Pro-Life movement. Several bioethicists have, however, opposed the idea of a disgust-based morality.(2) Recent findings in cognitive science support the view that the strong negative emotions people often experience when faced with biotechnological ideas are not expressions of inner wisdom. The negative emotions may rather be the result of a cognitive violation the biotechnological innovations easily cause. Due to their evolutionary background, people have certain automatic and quick cognitive tendencies routinely used for categorizing and reasoning about nature, usually termed 'folk biology'. Biotechnological processes like hybridisation and cloning clearly violate several of the cognitive rules people naturally apply for the explanation and categorization of their natural environment. As the cognitive tendencies routinely applied to the explanation of biological world are violated, an emotional response of fear, disgust and of something unnatural being underway is easily provoked. It is suggested in this paper that the reason behind the Yuck-factor is not a deep inner wisdom, but a violation of natural human cognitive tendencies concerning the biological world.

CD73 is required for efficient entry of lymphocytes into the central nervous system during experimental autoimmune encephalomyelitis.

CD73 is a cell surface enzyme of the purine catabolic pathway that catalyzes the breakdown of AMP to adenosine. Because of the strong immunosuppressive and antiinflammatory properties of adenosine, we predicted that cd73(-/-) mice would develop severe experimental autoimmune encephalomyelitis (EAE), an animal model for the central nervous system (CNS) inflammatory disease, multiple sclerosis. Surprisingly, cd73(-/-) mice were resistant to EAE. However, CD4 T cells from cd73(-/-) mice secreted more proinflammatory cytokines than wild-type (WT) mice and were able to induce EAE when transferred into naïve cd73(+/+) T cell-deficient recipients. Therefore, the protection from EAE observed in cd73(-/-) mice was not caused by a deficiency in T cell responsiveness. Immunohistochemistry showed that cd73(-/-) mice had fewer infiltrating lymphocytes in their CNS compared with WT mice. Importantly, susceptibility to EAE could be induced in cd73(-/-) mice after the transfer of WT CD73(+)CD4(+) T cells, suggesting that CD73 must be expressed either on T cells or in the CNS for disease induction. In the search for the source of CD73 in the CNS that might facilitate lymphocyte migration, immunohistochemistry revealed a lack of CD73 expression on brain endothelial cells and high expression in the choroid plexus epithelium which regulates lymphocyte immunosurveillance between the blood and cerebrospinal fluid. Because blockade of adenosine receptor signaling with the A(2a) adenosine receptor-specific antagonist SCH58261 protected WT mice from EAE induction, we conclude that CD73 expression and adenosine receptor signaling are required for the efficient entry of lymphocytes into the CNS during EAE development.

Cardiac Function After Cardiotoxic Treatments for Childhood Cancer-Left Ventricular Longitudinal Strain in Screening.

Background: The majority of childhood cancer survivors (CCSs) have been exposed to cardiotoxic treatments and often present with modifiable cardiovascular risk factors. Our aim was to evaluate the value of left ventricular (LV) longitudinal strain for increasing the sensitivity of cardiac dysfunction detection among CCSs. Methods: We combined two national cohorts: neuroblastoma and other childhood cancer survivors treated with anthracyclines. The final data consisted of 90 long-term CCSs exposed to anthracyclines and/or high-dose chemotherapy with autologous stem cell rescue and followed up for > 5 years and their controls (n = 86). LV longitudinal strain was assessed with speckle tracking (Qlab) and LV ejection fraction (EF) by three-dimensional echocardiography (3DE). Results: Of the CCSs, 11% (10/90) had abnormal LV longitudinal strain (i.e., < -17.5%); of those, 70% (7/10) had normal 3DE LV EF. Multivariable linear model analysis demonstrated that follow-up time (p = 0.027), sex (p = 0.020), and BMI (p = 0.002) were significantly associated with LV longitudinal strain. Conversely, cardiac risk group, hypertension, age, cumulative anthracycline dose or exposure to chest radiation were not. Conclusion: LV longitudinal strain is a more sensitive method than LV EF for the detection of cardiac dysfunction among CCSs. Therefore, LV longitudinal strain should be added to the screening panel, especially for those with modifiable cardiovascular risk factors.

Macrophage mannose receptor on lymphatics controls cell trafficking.

Macrophage mannose receptor (MR) participates in pathogen recognition, clearance of endogenous serum glycoproteins, and antigen presentation. MR is also present on lymphatic vessels, where its function is unknown. Here we show that migration of lymphocytes from the skin into the draining lymph nodes through the afferent lymphatics is reduced in MR-deficient mice, while the structure of lymphatic vasculature remains normal in these animals. Moreover, in a tumor model the primary tumors grow significantly bigger in MR(-/-) mice than in the wild-type (WT) controls, whereas the regional lymph node metastases are markedly smaller. Adhesion of both normal lymphocytes and tumor cells to lymphatic vessels is significantly decreased in MR-deficient mice. The ability of macrophages to present tumor antigens is indistinguishable between the 2 genotypes. Thus, MR on lymphatic endothelial cells is involved in leukocyte trafficking and contributes to the metastatic behavior of cancer cells. Blocking of MR may provide a new approach to controlling inflammation and cancer metastasis by targeting the lymphatic vasculature.

Mechanism of action of IFN-beta in the treatment of multiple sclerosis: a special reference to CD73 and adenosine.

IFN-beta treatment reduces the relapse rate in multiple sclerosis (MS), but the exact mechanism of action of the drug has remained elusive. CD73 (ecto-5'-nucleotidase) is an ectoenzyme, which produces adenosine from adenosine monophosphate (AMP) precursor by enzymatic dephosphorylation. AMP is known to be abundantly present at sites of inflammation, and more importantly adenosine, the product of CD73, is known to possess both anti-inflammatory and neuroprotective activity. Our preliminary work has shown that IFN-beta increases the expression of ecto-5'-nucleotidase on endothelial cells (ECs) both in vitro and after systemic treatment of MS patients in vivo. In the majority of MS patients also an increase in the soluble serum CD73 was noted after IFN-beta treatment. Importantly, this correlated with the clinical outcome. CD73 expression on central nervous system (CNS) microvasculature was confirmed with stainings of frozen tissue sections of MS brain samples taken at autopsy. Adenosine, a known neuroprotective agent, might contribute to the beneficial effects of IFN-beta on MS.

Stress-Dose Corticosteroid Versus Placebo in Neonatal Cardiac Operations: A Randomized Controlled Trial.

BACKGROUND: Corticosteroids can improve the hemodynamic status of neonates with postoperative low cardiac output syndrome after cardiac operations. This study compared a prophylactically administered stress-dose corticosteroid (SDC) regimen against placebo on inflammation, adrenocortical function, and hemodynamic outcome. METHODS: Forty neonates undergoing elective open heart operations were randomized into two groups. The SDC group received perioperatively 2 mg/kg methylprednisolone, and 6 hours after the operation, a hydrocortisone infusion (0.2 mg/kg/h) was started with tapering doses for 5 days. Placebo was administered in a similar fashion. An adrenocorticotropic hormone stimulation test was performed after the therapy. The primary endpoint of the study was plasma concentration of interleukin (IL-6). Secondary clinical outcomes included plasma cortisol, IL-10, C-reactive protein, echocardiographic systemic ventricle contractility evaluated by the Velocity Vector Imaging program, the inotropic score, and time of delayed sternal closure. RESULTS: The IL-6 values of the SDC group were significantly lower postoperatively than in the placebo group. Significantly lower inotropic scores (p < 0.05), earlier sternal closure (p = 0.03), and less deterioration in the systemic ventricle mean delta strain values between the preoperative and the first postoperative assessment (p = 0.01) were detected for the SDC group. The SDC therapy did not suppress the hypothalamic-pituitary-adrenal axis more than placebo. The mean plasma cortisol level did not decline in the placebo group after the operation. CONCLUSIONS: The SDC regimen for 5 days postoperatively in neonates was safe and did not cause suppression of the hypothalamic-pituitary-adrenal axis. Furthermore, the open heart operation per se did not lead to adrenal insufficiency in neonates.

Aetiology of febrile pharyngitis in children: Potential of myxovirus resistance protein A (MxA) as a biomarker of viral infection.

OBJECTIVES: Besides group A streptococcus (GAS), microbial causes of pharyngitis in children are not well known. We aimed to document the viral and bacterial aetiology of pharyngitis and to assess the pathogenic role of viruses by determining the myxovirus resistance protein A (MxA) in the blood as a marker of interferon response. METHODS: In this prospective observational study, throat swabs and blood samples were collected from children (age 1-16 years) presenting to the emergency department with febrile pharyngitis. Microbial cause was sought by bacterial culture, polymerase chain reaction, and serology. Blood MxA level was determined. RESULTS: A potential pathogen was detected in 88% of 83 patients: GAS alone in 10%, GAS and viruses in 13%, group C or G streptococci alone in 2% and together with viruses in 3%, and viruses alone in 59% of cases. Enteroviruses, rhinoviruses, and adenoviruses were the most frequently detected viruses. Blood MxA levels were higher in children with viral (880 [245-1250] µg/L; median [IQR]) or concomitant GAS-viral (340 [150-710] µg/L) than in those with sole GAS (105 [80-160] µg/L) infections. CONCLUSIONS: Detection of respiratory viruses simultaneously with elevated blood MxA levels supports the causative role of viruses in the majority of children with pharyngitis.

Accuracy and feasibility of point-of-care white blood cell count and C-reactive protein measurements at the pediatric emergency department.

BACKGROUND: Several point-of-care (POC) tests are available for evaluation of febrile patients, but the data about their performance in acute care setting is sparse. We investigated the analytical accuracy and feasibility of POC tests for white blood cell (WBC) count and C-reactive protein (CRP) at the pediatric emergency department (ED). METHODS: In the first part of the study, HemoCue WBC and Afinion AS100 CRP POC analyzers were compared with laboratory's routine WBC (Sysmex XE-2100) and CRP (Modular P) analyzers in the hospital central laboratory in 77 and 48 clinical blood samples, respectively. The POC tests were then adopted in use at the pediatric ED. In the second part of the study, we compared WBC and CRP levels measured by POC and routine methods during 171 ED patient visits by 168 febrile children and adolescents. Attending physicians performed POC tests in capillary fingerprick samples. RESULTS: In parallel measurements in the laboratory both WBC and CRP POC analyzers showed good agreement with the reference methods. In febrile children at the emergency department (median age 2.4 years), physician performed POC determinations in capillary blood gave comparable results with those in venous blood analyzed in the laboratory. The mean difference between POC and reference test result was 1.1 E9/L (95% limits of agreement from -6.5 to 8.8 E9/L) for WBC and -1.2 mg/L (95% limits of agreement from -29.6 to 27.2 mg/L) for CRP. CONCLUSIONS: POC tests are feasible and relatively accurate methods to assess CRP level and WBC count among febrile children at the ED.

Identification of respiratory viruses with a novel point-of-care multianalyte antigen detection test in children with acute respiratory tract infection.

BACKGROUND: Rapid etiological diagnosis of a respiratory virus infection may have impact on antiviral and antibiotic therapy, patient cohorting, and prediction of the clinical course. Most point-of-care tests for detection of respiratory viruses have limitations in diagnostic performance and clinical usability. A novel, multianalyte point-of-care antigen detection test system (mariPOC(®); ArcDia International Oy Ltd., Turku, Finland) detects eight respiratory viruses (influenza A and B viruses, respiratory syncytial virus (RSV), adenovirus, human metapneumovirus, and parainfluenza type 1, 2, and 3 viruses) from a single nasopharyngeal swab specimen by a fully automated, random-access immunoassay method. OBJECTIVES: To evaluate mariPOC(®) point-of-care test system in comparison with reverse transcription polymerase chain reaction (RT-PCR) in a pediatric emergency department setting. STUDY DESIGN: Prospectively collected samples from 158 children (mean age, 1.8 years) with respiratory symptoms and/or fever were analyzed both by mariPOC(®) and by multiplex RT-PCR. RESULTS: The sensitivities and specificities (95% confidence intervals) of the mariPOC(®) test were for influenza A (n = 7), 71% (38-100) and 100%; influenza B (n = 22), 86% (72-100) and 98% (95-100); RSV (n = 35), 89% (78-99) and 100%; adenovirus (n = 12), 25% (1-50) and 97% (95-99); and for human metapneumovirus (n = 8), 50% (15-85) and 100%, respectively. Parainfluenzaviruses were detected only in five patients. CONCLUSIONS: This novel point-of-care test system is a rapid, practical, and specific method for simultaneous detection of eight respiratory viruses. Compared with RT-PCR, its sensitivity is moderately high for detection of RSV and influenza viruses, and low for adenovirus.

Human rhinovirus C--associated severe pneumonia in a neonate.

We present a case of severe pneumonia, associated with a prolonged infection by a species C rhinovirus (HRV) in a 3-week old neonate. HRV RNA was identified in nasal and nasopharyngeal secretions, bronchoalveolar lavage and bronchial specimens, stool and urine, collected from the patient during a one-month period. No other viral or bacterial agents were detected. Sequence analysis of two regions of the viral genome, amplified directly from the clinical specimens revealed a novel HRV-C variant. These observations highlight the occurrence of severe neonatal infections caused by HRVs and the need of rapid viral diagnostics for their detection.

IFN-beta regulates CD73 and adenosine expression at the blood-brain barrier.

IFN-beta treatment reduces the relapse rate in MS but its mechanism of action remains incompletely understood. Our aim was to clarify the beneficial effect of IFN-beta in the treatment of MS. We assessed the influence of IFN-beta treatment on (i) CD73 expression on the surface of primary cultures of human blood-brain barrier endothelial cells (BBB-EC) and human astrocytes using immunofluorescence staining and flow cytometry, (ii) transmigration of CD4+ T lymphocytes using an in vitro model of BBB and (iii) CD73 enzyme activity, i.e. ecto-5'-nucleotidase activity in the serum of MS patients using a radiochemical assay. IFN-beta increases the expression of ecto-5'-nucleotidase both on BBB-EC and astrocytes. As a consequence, lymphocyte transmigration through BBB-EC is reduced. Importantly, this reduction can be reversed using alpha,beta-methyleneadenosine-5'-diphosphate, a specific inhibitor of ecto-5'-nucleotidase. CD73 is strongly expressed in microvasculature in samples of postmortem MS brain and, moreover, in the majority of MS patients there was a clear upregulation both in the soluble serum ecto-5'-nucleotidase activity and skin microvascular CD73 expression after IFN-beta treatment. Upregulation of ecto-5'-nucleotidase and a subsequent increase in adenosine production might contribute to the beneficial effects of IFN-beta on MS via enhancing the endothelial barrier function.

IFN-alpha induced adenosine production on the endothelium: a mechanism mediated by CD73 (ecto-5'-nucleotidase) up-regulation.

CD73 (ecto-5'-nucleotidase; EC 3.1.3.5) participates in lymphocyte binding to endothelial cells and converts extracellular AMP into a potent anti-inflammatory substance adenosine. However, the regulation of expression and function of CD73 has remained largely unknown. In this study, we show that IFN-alpha produces a time- and dose-dependent long-term up-regulation of CD73 on endothelial cells, but not on lymphocytes both at protein and RNA levels. Moreover, CD73-mediated production of adenosine is increased after IFN-alpha treatment on endothelial cells, resulting in a decrease in the permeability of these cells. Subsequent to induction with PMA, FMLP, dibutyryl cAMP, thrombin, histamine, IL-1beta, TNF-alpha, and LPS, no marked changes in the level of CD73 expression on endothelial cells are observed. We also show that CD73 is up-regulated in vivo on the vasculature after intravesical treatment of urinary bladder cancers with IFN-alpha. In conclusion, distinct behavior of lymphocyte and endothelial CD73 subsequent to cytokine treatment further emphasizes the existence of cell type-specific mechanisms in the regulation of CD73 expression and function. Overall, these results suggest that IFN-alpha is a relevant in vivo regulator of CD73 in the endothelial-leukocyte microenvironment in infections/inflammations, and thus has a fundamental role in controlling the extent of inflammation via CD73-dependent adenosine production.