Intestinal microbiota composition after antibiotic treatment in early life: the INCA study.

BACKGROUND: The acquisition and development of infant gut microbiota can be influenced by numerous factors, of which early antibiotic treatment is an important one. However, studies on the effects of antibiotic treatment in early life on clinical outcomes and establishment and development of the gut microbiota of term infants are limited. Disturbed microbiota composition is hypothesized to be an underlying mechanism of an aberrant development of the immune system. This study aims to investigate the potential clinical and microbial consequences of empiric antibiotic use in early life. METHODS/DESIGN: 450 term born infants, of whom 150 are exposed to antibiotic treatment in early life and 300 are not (control group), are included in this observational cohort study with a one-year follow-up. Clinical outcomes, including coughing, wheezing, fever >38 °C, runny nose, glue ear, rash, diarrhea and >3 crying hours a day, are recorded daily by parents and examined by previously defined doctor's diagnosis. A blood sample is taken at closure to investigate the infant's vaccination response and sensitization for food and inhalant allergens. Fecal samples are obtained at eight time points during the first year of life. Potential differences in microbial profiles of infants treated with antibiotics versus healthy controls will be determined by use of 16S-23S rRNA gene analysis (IS-pro). Microbiota composition will be described by means of abundance, diversity and (dis)similarity. Diversity is calculated using the Shannon index. Dissimilarities between samples are calculated as the cosine distance between each pair of samples and analyzed with principal coordinate analysis. Clinical variables and possible associations are assessed by appropriate statistics. DISCUSSION: Both clinical quantitative and qualitative microbial effects of antibiotic treatment in early life may be demonstrated. These findings can be important, since there is evidence that manipulation of the infant microbiota by using pre- or probiotics can restore the ecological balance of the microbiota and may mitigate potential negative effects on the developing immune system, when use of antibiotics cannot be avoided. TRIAL REGISTRATION: ClinicalTrials.gov NCT02536560. Registered 28 August 2015.

Response to pneumococcal vaccination in mannose-binding lectin-deficient adults with recurrent respiratory tract infections.

Mannose-binding lectin (MBL)-deficiency is associated with an increased susceptibility to pneumococcal infections and other forms of disease. Pneumococcal vaccination is recommended in MBL-deficient patients with recurrent respiratory tract infections (RRTI). The response to pneumococcal vaccination in MBL-deficient individuals has not yet been studied in detail. An impaired response to pneumococcal polysaccharides in MBL-deficient patients might explain the association between MBL deficiency and pneumococcal infections. This study investigates the antibody response to pneumococcal vaccination in MBL-deficient adult patients with RRTI. Furthermore, we investigated whether there was a difference in clinical presentation between MBL-deficient and -sufficient patients with RRTI. Eighteen MBL-deficient and 63 MBL-sufficient adult patients with RRTI were all vaccinated with the 23-valent pneumococcal polysaccharide vaccine and antibodies to 14 pneumococcal serotypes were measured on a Luminex platform. There were no differences observed in the response to pneumococcal vaccination between MBL-sufficient and -deficient patients. Forty-three MBL-sufficient patients could be classified as responders to pneumococcal vaccination and 20 as low responders, compared to 15 responders and three low responders in the MBL-deficient patients. We found no clear difference in clinical, radiological, lung function and medication parameters between MBL-sufficient and -deficient patients. In conclusion, our study suggests that MBL-deficient adults with RRTI have a response to a pneumococcal capsular polysaccharide vaccine comparable with MBL-sufficient patients. Moreover, we did not find a clear clinical role of MBL deficiency in adults with RRTI. As MBL deficiency is associated with an increased susceptibility to pneumococcal infections, pneumococcal vaccination might be protective in MBL-deficient patients with RRTI.

Increased incidence of serotype-1 invasive pneumococcal disease in young female adults in The Netherlands.

Analysis of the Dutch national invasive pneumococcal disease (IPD) surveillance data by sex reveals an increase in the incidence of serotype-1 disease in young female adults in The Netherlands after the introduction of the 7-valent pneumococcal conjugate vaccine (PCV7) in the national immunization schedule. This has led to an overall increase in IPD in women aged 20-45 years, which was not observed in men of the same age. No other differences in serotype shifts possibly induced by the introduction of PCV7 were observed between the sexes in this age group. Serotype 1 is a naturally fluctuating serotype in Europe and it has been associated with disease in young healthy adults before. It remains uncertain whether or not there is an association between the observed increase in serotype-1 disease in young female adults and the implementation of PCV7 in The Netherlands.

Reduced local immune response with continuous positive airway pressure during one-lung ventilation for oesophagectomy.

BACKGROUND: Transthoracic oesophagectomy requires prolonged one-lung ventilation causing systemic and local inflammatory responses. Application of continuous positive airway pressure (CPAP) to the collapsed lung potentially reduces pulmonary damage, hypoxia, and consequent inflammation. This randomized controlled trial studied the influence of CPAP applied to the collapsed right lung during thoracoscopic oesophagectomy on local and systemic inflammatory response. METHODS: Broncho-alveolar lavage fluid (BALF) from the right collapsed and left ventilated lung and serum samples were obtained during surgery from 30 patients undergoing thoracolaparoscopic oesophagectomy for cancer who were randomized for one-lung ventilation with or without CPAP applied to the collapsed right lung. Concentrations of cytokines and chemokines, in BALF and serum, were determined with Luminex. RESULTS: Patients from the control (no CPAP) group had significantly increased concentrations of interleukin (IL)-1α, IL-1ß, IL-10, tumour necrosis factor-alpha, macrophage inflammatory protein (MIP)-1α, pulmonary and activation-regulated chemokine (PARC), and IL-8 in the collapsed (right) lung when compared with patients from the CPAP group (P<0.05). The ventilated (left) lung of the control group showed increased concentrations of monocyte chemoattractant protein (MCP)-1 and MIP-1α (P<0.05). Serum concentrations of cytokines and chemokines increased during surgery, but did not differ between the control and CPAP groups. CONCLUSIONS: A significantly lower local immune response was observed during one-lung ventilation when CPAP was applied to the collapsed lung. The findings suggest a beneficial effect of CPAP on the collapsed lung during oesophagectomy with one-lung ventilation.

Influence of repeated maximal exercise testing on biomarkers and fatigue in sarcoidosis.

Fatigue in the immune mediated inflammatory disease sarcoidosis is thought to be associated with impaired exercise tolerance. This prospective study assessed fatigue and recuperative capacity after repeated exercise, and examined whether changing concentrations in biomarkers upon exercise are associated with fatigue. Twenty sarcoidosis patients and 10 healthy volunteers performed maximal cardiopulmonary exercise tests on two successive days. Concentrations of cytokines, stress hormones, ACE and CK were assessed before and after the two exercise tests, and 3 days thereafter. All participants completed a sleep diary. Severely fatigued patients showed significant lower VO2 max (p=0.038, p=0.022) and maximal workload (p=0.034, p=0.028) on both exercise tests compared to healthy controls. No impairment of maximal exercise testing was demonstrated during the second cycling test in any group. Fatigue was not correlated with changes in concentrations of biomarkers upon exercise. Severely fatigued patients rated both tests as significantly more fatiguing, and reported significant lower mean subjective night sleeping time during the testing period. Fatigue in sarcoidosis patients cannot be objectified by reduction of exercise capacity after repeated maximal exercise testing, and is not correlated with significant changes in biomarkers. Severe fatigue is only and consistently featured by patient reported outcomes.

Mutations in MVK, encoding mevalonate kinase, cause hyperimmunoglobulinaemia D and periodic fever syndrome.

Hyperimmunoglobulinaemia D and periodic fever syndrome (HIDS; MIM 260920) is an autosomal recessive disorder characterized by recurrent episodes of fever associated with lymphadenopathy, arthralgia, gastrointestinal dismay and skin rash. Diagnostic hallmark of HIDS is a constitutively elevated level of serum immunoglobulin D (IgD), although patients have been reported with normal IgD levels. To determine the underlying defect in HIDS, we analysed urine of several patients and discovered increased concentrations of mevalonic acid during severe episodes of fever, but not between crises. Subsequent analysis of cells from four unrelated HIDS patients revealed reduced activities of mevalonate kinase (MK; encoded by the gene MVK), a key enzyme of isoprenoid biosynthesis. Sequence analysis of MVK cDNA from the patients identified three different mutations, one of which was common to all patients. Expression of the mutant cDNAs in Escherichia coli showed that all three mutations affect the activity of the encoded proteins. Moreover, immunoblot analysis demonstrated a deficiency of MK protein in patient fibroblasts, indicating a protein-destabilizing effect of the mutations.

Treatment with anti-inflammatory drugs in community-acquired pneumonia.

Pneumonia exhibits a broad range of severity, from mildly symptomatic at one end to fulminant septic shock and death at the other. Although an adequate inflammatory response is necessary for the clearance of microorganisms, excessive inflammation can lead to ongoing local and systemic damage. Because of this extended inflammatory response despite appropriate antibiotic therapy, as well as increasing antibiotic resistance, adjuvant therapy for pneumonia that can favourably modify the immune response has become an increasingly relevant approach to improve prognosis. Different adjuvant treatment options for pneumonia have recently been proposed. Promising treatment options include corticosteroids, statins, macrolides and Toll-like receptor antagonists. The aim of this review is to summarize the inflammatory response during pneumonia and discuss the current knowledge and future perspectives regarding the anti-inflammatory treatment options for patients with pneumonia.

Genetic variation in the Toll-like receptor gene cluster (TLR10-TLR1-TLR6) influences disease course in sarcoidosis.

Sarcoidosis is an inflammatory disease of unknown etiology. Various microorganisms have been proposed as etiologic agent suggesting a role for pattern-recognition receptors such as Toll-like receptors (TLRs) in disease pathogenesis, with a special interest in TLR-2. TLR-10, TLR-1, and TLR-6 act as co-receptors for TLR-2 and the genes encoding these receptors are located in a gene cluster on chromosome 4. The aim of our study was to assess differences in genetic variation in the TLR10-TLR1-TLR6 gene cluster between patients and controls. A total of eight single nucleotide polymorphisms were genotyped in 447 healthy controls and 533 patients, divided in 425 with sarcoidosis and 108 with Löfgren's syndrome. Comparison of the total patient cohort with controls showed that the allele frequencies of rs1109695, rs7658893 (TLR-10), and rs5743604 as well as rs5743594 (TLR-1) differed significantly. Haplotype analysis showed that the most common haplotype found was significantly decreased in patients with chronic sarcoidosis. Furthermore, a less common haplotype was found to be significantly increased in patients with Löfgren's syndrome as well as sarcoidosis patients with self-remitting disease, indicating that it could act as a disease modifying haplotype. In conclusion, our study suggests that absence of the common haplotype in the TLR10-TLR1-TLR6 gene cluster increases the risk of developing chronic disease in patients already affected by sarcoidosis. Based on their role as co-receptors for TLR-2, this study supports the growing evidence that aberrant TLR-2 function is important in sarcoidosis disease pathogenesis.

Prediction of asthma exacerbations in children: results of a one-year prospective study.

BACKGROUND: Underdiagnosis and low levels of asthma control are frequent occurring problems in patients with asthma. OBJECTIVE: The study aim was to evaluate the ability of non-invasive inflammatory markers in exhaled breath to predict exacerbations of childhood asthma, and to assess the time course of changes in these exhaled markers before, during and after exacerbations. METHODS: The design was a prospective one-year longitudinal study. Regular two-month visits at the outpatient clinic were performed. Forty children with asthma (aged 6-16 years) participated. The primary outcome measure was the occurrence of an exacerbation. Assessment was made of the presence and severity of pulmonary symptoms, use of medication, and measurements of forced expiratory volume in 1 s using home monitor. The following independent parameters were assessed during outpatient visits: (1) exhaled nitric oxide, (2) inflammatory markers in exhaled breath condensate: acidity, nitrite, hydrogen peroxide, interleukin-1α, -5, -13, interferon-γ, (3) lung function, (4) asthma control score. RESULTS: Thirty-eight of 40 children completed the study. Sixteen children developed exacerbations, of which ten were moderate and six severe. Univariate Cox regression analysis revealed that condensate acidity, interleukin-5 and asthma control score were significant predictors of an asthma exacerbation (P < 0.05). In the multivariate Cox regression analysis, exacerbations were best predicted by the asthma control score and by the level of interleukin-5 in exhaled breath condensate (Wald scores of 7.19 and 4.44, P = 0.007 and P = 0.035 respectively). The predicted survival curve of this multivariate model showed a two times reduced risk on exacerbations in the category of children with the 10% most optimal values of IL-5 and asthma control score. CONCLUSIONS AND CLINICAL RELEVANCE: Both exhaled breath condensate interleukin-5 level and asthma control score were significant predictors of asthma exacerbations. These findings open up the possibility of assessing the potential of such parameters to titrate asthma treatment in future studies.

Probiotic treatment with Probioflora in patients with predicted severe acute pancreatitis without organ failure.

BACKGROUND: We previously demonstrated that probiotic prophylaxis, in patients with predicted severe pancreatitis, did not prevent infectious complications but unexpectedly increased the risk of bowel ischemia and mortality. The suggestion that these negative findings are only observed in the presence of organ failure at the start of probiotic treatment has not been confirmed. METHODS: In a retrospective analysis, all patients with predicted severe acute pancreatitis without initial organ failure admitted to a medium care facility of a teaching hospital in Prague from January 2003 to December 2010 were included. All patients routinely received probiotic treatment with Probioflora. Total parenteral nutrition (TPN) was routinely started and shifted toward total enteral nutrition. Infectious complications, mortality and the incidence of bowel ischemia were recorded. RESULTS: 99 consecutive patients, mean age 56 years, were included. Infectious complications occurred in 42 patients (42%), consisting of bacteremia (n = 40), pneumonia (n = 11) and infected necrosis (n = 11). Bowel ischemia was detected in two patients (2%). Overall mortality was 8%. CONCLUSION: In this retrospective study no apparent positive or negative impact of probiotic treatment with Probioflora was demonstrated when administered to patients with predicted severe acute pancreatitis without initial organ failure.

Symptoms, but not a biomarker response to inhaled corticosteroids, predict asthma in preschool children with recurrent wheeze.

BACKGROUND: A reliable asthma diagnosis is challenging in preschool wheezing children. As inhaled corticosteroids (ICS) are more effective in asthmatics than in children with transient wheeze, an ICS response might be helpful in early asthma diagnosis. METHODS: 175 children (aged two-four years) with recurrent wheeze received 200 µg Beclomethasone extra-fine daily for eight weeks. Changes in Exhaled Breath Condensate (EBC) biomarkers (pH, interleukin (IL)-1α, IL-2, IL-4, IL-5, IL-10, IFN-γ, sICAM, and CCL-11), Fractional exhaled Nitric Oxide (FeNO), airway resistance, and symptoms were assessed. At six years of age a child was diagnosed as transient wheezer or asthmatic. Adjusted logistic regression analysis was performed with multiple testing correction. RESULTS: 106 transient wheezers and 64 asthmatics were analysed at six years of age. Neither changes in EBC biomarkers, nor FeNO, airway resistance, or symptoms during ICS trial at preschool age were related to asthma diagnosis at six years of age. However, asthmatics had more airway symptoms before the start of the ICS trial than transient wheezers (P < 0.01). DISCUSSION: Although symptom score in preschool wheezing children at baseline was associated with asthma at six years of age, EBC biomarkers, airway resistance, or symptom response to ICS at preschool age could not predict asthma diagnosis at six years of age.

Serologic response to a third dose of an mRNA-based SARS-CoV-2 vaccine in lung transplant recipients.

Lung transplant recipients have an increased risk for severe coronavirus disease 2019 (COVID-19) due to infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). A third dose of a SARS-CoV-2 vaccine has been recommended for all solid organ transplant recipients, but data from lung transplant recipients specifically are scarce. In this study, the serologic response to a third dose of an mRNA-based SARS-CoV-2 vaccine was measured in 78 lung transplant recipients. Sixty-two percent (n = 48) had a serological response to vaccination, which was significantly higher than after the second vaccine dose (27 patients (35%); p = 0.0013). A positive serologic response was associated with having had COVID-19 (p = 0.01), and higher serum IgG level and complement mannose binding lectin pathway activity prior to vaccination (p = 0.04 and p = 0.03, respectively). Serologic response was not associated with the dose of mycophenolate mofetil or prednisone or other immune status parameters. Eleven patients (14%) developed COVID-19 after the second or third vaccine dose, but this did not associate with serologic response after the second vaccine dose (9% in patients who developed COVID-19 versus 39% in patients who did not develop COVID-19 (p = 0.09)), or with serologic response above cut-off values associated with clinical protection in previous studies. In conclusion, the response to mRNA-based SARS-CoV-2 vaccines in lung transplant recipients improves significantly after a third vaccine dose. Factors associated with a positive serologic response are having had COVID-19 prior to vaccination, and serum IgG and complement mannose binding lectin pathway activity prior to vaccination. Serologic response did not associate with clinical protection against COVID-19 in this study.

Response to influenza virus vaccination during chemotherapy in patients with breast cancer.

BACKGROUND: Patients receiving chemotherapy are at increased risk for influenza virus infection. Little is known about the preferred moment of vaccination during chemotherapy. PATIENTS AND METHODS: Breast cancer patients received influenza vaccination during FEC (5-fluorouracil, epirubicin and cyclophosphamide)-containing chemotherapy regimens. Patients were randomised for early (day 4) or late (day 16) vaccination during the chemotherapy cycle. Influenza virus-specific antibody titres were determined before and 3 weeks after vaccination by haemagglutination inhibition. RESULTS: We included 38 breast cancer patients (20 in the early and 18 in the late group) and 21 healthy controls. The overall patient group had significant lower responses to the vaccine compared with healthy controls. Patients vaccinated at day 4 tended to have higher antibody titres as compared with patients vaccinated at day 16, although the difference in post-vaccination titres is not statistically significant. Geometric mean titres post-vaccination for day 4 versus day 16 were 63.7 versus 29.5 (H3N2), 28.2 versus 19.6 (H1N1) and 29.8 versus 16.0 (B/Brisbane), respectively. CONCLUSIONS: Patients on chemotherapy have significantly lower responses to influenza virus vaccination compared with healthy controls. Vaccination early during the chemotherapy cycle induces better responses than does vaccination at day 16 of the cycle. Follow-up studies are needed to confirm this effect.

Systemic cytokine response in patients with community-acquired pneumonia.

The role of individual cytokines and polymorphisms in pneumonia has been described, but the relationship between different cytokines and polymorphisms in relation to causative microorganisms, antibiotics, corticosteroids and clinical course has not. This study questions the relationship between cytokines, polymorphisms and clinical characteristics of pneumonia. Patients diagnosed with pneumonia were included in the study. Serum cytokine levels were measured during hospital stay, genotyping was performed, causative microorganisms were identified and patients were monitored throughout the hospital stay. In 201 patients with pneumonia interleukin (IL)-1 receptor antagonist (IL-1RA), IL-6, IL-8 and IL-10 acted as acute phase proteins. After admission, the levels of these cytokines decreased rapidly. Single nucleotide polymorphisms did not influence cytokine production and were not associated with clinical outcome. Cytokine serum levels were significantly higher in patients with pneumococcal pneumonia. The decrease in levels of cytokines was independently influenced by the start of corticosteroid therapy. IL-1RA, IL-6, IL-8 and IL-10 are acute phase proteins, independent of genotype. Their levels are influenced by the nature of the causative microorganism and the start of corticosteroids therapy.

Genetic variability in the IL1RN gene and the balance between interleukin (IL)-1 receptor agonist and IL-1ß in idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a rapidly progressive interstitial lung disease of unknown aetiology. Interleukin (IL)-1ß plays an important role in inflammation and has been associated with fibrotic remodelling. We investigated the balance between IL-1ß and IL-1 receptor antagonist (IL-1Ra) in bronchoalveolar lavage fluid (BALF) and serum as well as the influence of genetic variability in the IL1B and IL1RN gene on disease susceptibility and cytokine levels. In 77 IPF patients and 349 healthy controls, single nucleotide polymorphisms (SNPs) in the IL1RN and IL1B genes were determined. Serum and BALF IL-1Ra and IL-1ß levels were measured using a multiplex suspension bead array system and were correlated with genotypes. Both in serum and BALF a significantly decreased IL-1Ra/IL-1ß ratio was found in IPF patients compared to healthy controls. In the IL1RN gene, one SNP was associated with both the susceptibility to IPF and reduced IL-1Ra/IL-1ß ratios in BALF. Our results show that genetic variability in the IL1RN gene may play a role in the pathogenesis of IPF and that this role may be more important than thought until recently. The imbalance between IL-1Ra and IL-1ß might contribute to a proinflammatory and pro-fibrotic environment in their lungs.

Can exhaled inflammatory markers predict a steroid response in wheezing preschool children?

BACKGROUND: The efficacy of inhaled corticosteroids (ICS) varies among wheezing preschool children. Currently, it is not possible to predict which fraction of wheezing children will benefit from an ICS treatment. OBJECTIVE: We explored whether fractional exhaled nitric oxide (FeNO) and inflammatory markers in exhaled breath condensate (EBC) can predict an ICS response in preschool wheezers. METHODS: An 8-week ICS study (registered at Clinicaltrial.gov: NCT 00422747; 200 µg; beclomethasone extra-fine daily) was performed in 93 wheezing children (age range 2.0-4.4 years). At baseline, FeNO was determined off-line. EBC was collected using a closed glass-condenser. The acidity of EBC was determined and other EBC markers [interleukin (IL)-1α, IL-2, IL-4, IL-5, IL-10, soluble intercellular adhesion molecule, interferon-γ, eotaxin] were measured using a multiplex immunoassay. The change in airway resistance (Rint) and symptom score following ICS treatment was related to atopy (positive Phadiatop Infant test), FeNO and EBC markers. RESULTS: Airway resistance and symptoms mildly improved after ICS treatment [median (IQR): 1.4 (1.2-1.7) to 1.3 (1.1-1.5) kPa s/L, symptom score: 26 (23-28) to 28 (24-29), P < 0.01, respectively]. Only IL-10 and atopy had limited predictive value regarding a change in symptoms [ß (SE) =-0.13 (0.07), P = 0.08, ß (SE) = 2.05 (1.17), P = 0.08, respectively]. CONCLUSIONS AND CLINICAL RELEVANCE: We did not find convincing evidence that FeNO and EBC markers could predict an ICS response in preschool wheezers. Recommendations for future studies on this topic are given.

Impaired antibody response to conjugated meningococcal serogroup C vaccine in asplenic patients.

The purpose of this study was to determine the quantity and quality of antibodies against the meningococcal serogroup C (MenC) conjugated vaccine in asplenic patients. In 116 asplenic patients, antibody concentrations (IgG) were measured against meningococcal serogroup C before and after immunisation. Of MenC-specific IgG, both antibody avidity and subclasses of IgG1 and IgG2 were determined. The mean MenC IgG concentration rose from 0.16 µg/mL prior to vaccination to 3.69 µg/mL 3 weeks post-vaccination, with 67% of patients reaching the threshold of ≥ 2.0 µg/mL. The mean IgG concentration at 35 weeks post-vaccination was 3.10 µg/mL. IgG2 concentrations increased more than IgG1. Marginal avidity maturation was seen. Hypo-responders to the first MenC vaccine (IgG anti-MenC ≤ 2.0 µg/mL) were offered a booster dose. After revaccination, 59% reached the chosen IgG threshold. The IgG concentration rose from 0.29 to 1.12 µg/mL, with an increase in the IgG1/IgG2 ratio. Avidity indices remained below 33%. In asplenic patients, the quantity and quality of antibodies produced after one dose of conjugated MenC vaccination is lower than that observed in previous studies in healthy adults. Booster vaccination does, indeed, lead to a rise in IgG geometric mean concentrations (GMCs), but does not lead to higher avidity of antibodies.

Performance of the Diasorin SARS-CoV-2 antigen detection assay on the LIAISON XL.

BACKGROUND: The current reference standard to diagnose a SARS-CoV-2 infection is real-time reverse transcriptase polymerase chain reaction (RT-PCR). This test poses substantial challenges for large-scale community testing, especially with respect to the long turnaround times. SARS-CoV-2 antigen tests are an alternative, but typically use a lateral flow assay format rendering them less suitable for analysis of large numbers of samples. METHODS: We conducted an evaluation of the Diasorin SARS-CoV-2 antigen detection assay (DAA) compared to real-time RT-PCR (Abbott). The study was performed on 248 (74 qRT-PCR positive, 174 qRT-PCR negative) clinical combined oro-nasopharyngeal samples of individuals with COVID-19-like symptoms obtained at a Municipal Health Service test centre. In addition, we evaluated the analytical performance of DAA with a 10-fold dilution series of SARS-CoV-2 containing culture supernatant and compared it with the lateral flow assay SARS-CoV-2 Roche/SD Biosensor Rapid Antigen test (RRA). RESULTS: The DAA had an overall specificity of 100% (95%CI 97.9%-100%) and sensitivity of 73% (95%CI 61.3%-82.7%) for the clinical samples. Sensitivity was 86% (CI95% 74.6%-93.3%) for samples with Ct-value below 30. Both the DAA and RRA detected SARS-CoV-2 up to a dilution containing 5.2 × 102 fifty-percent-tissue-culture-infective-dose (TCID50)/ml. DISCUSSION: The DAA performed adequately for clinical samples with a Ct-value below 30. Test performance may be further optimised by lowering the relative light unit (RLU) threshold for positivity assuming the in this study used pre-analytical protocol . The test has potential for use as a diagnostic assay for symptomatic community-dwelling individuals early after disease onset in the context of disease control.

Insulin-like growth factor induces phosphorylation of immunoreactive insulin receptor substrate and its association with phosphatidylinositol-3 kinase in human thymocytes.

Insulin receptor substrate 1 (IRS-1) is the principle cellular substrate for insulin and insulin-like growth factor I (IGF-I) receptor signaling. After phosphorylation of tyrosine residues within the YMXM or YXXM motifs, IRS-1 associates with phosphatidylinositol-3 kinase (PI3K). This signaling pathway and the presence of an IRS-1-like molecule have been demonstrated in IRS-1-transfected and in nontransfected hematopoietic cell lines, respectively. IGF-I has been implicated in lymphocyte development and function, and recently, we showed that functional type-I IGF receptors are present on human thymocytes and peripheral T cells. In this study, we addressed IGF-I signal transduction in nontransformed, freshly isolated, human thymocytes, as well as in blood T cells. Using Western blot analysis, we found that IGF-I induced phosphorylation of a 160-180-kD protein (pp170) in human thymocytes and that phosphorylated pp170 becomes associated with PI3K and is recognized by anti-IRS-1. In blood T cells, this immunoreactive IRS-1 (irIRS-1) is less abundantly expressed than in thymocytes, as assessed with immunoblotting. As a consequence, phosphorylated pp170 was not or hardly detectable after stimulation with IGF-I, and irIRS-1 was not detected in PI3K immunoprecipitates from lysates of IGF-I-stimulated T cells. However, IGF-I induced the tyrosine phosphorylation of other cellular proteins, indicating that differential expression of irIRS-1 contributes to a distinct signaling pathway in T cells.