Åse Bengård Andersen

Clinical significance of 2 h plasma concentrations of first-line anti-tuberculosis drugs: a prospective observational study

OBJECTIVESnTo study 2 h plasma concentrations of the first-line tuberculosis drugs isoniazid, rifampicin, ethambutol and pyrazinamide in a cohort of patients with tuberculosis in Denmark and to determine the relationship between the concentrations and the clinical outcome.nnnMETHODSnAfter 6-207 days of treatment (median 34 days) 2 h blood samples were collected from 32 patients with active tuberculosis and from three patients receiving prophylactic treatment. Plasma concentrations were determined using LC-MS/MS. Normal ranges were obtained from the literature. Clinical charts were reviewed for baseline characteristics and clinical status at 2, 4 and 6 months after the initiation of treatment. At a 1 year follow-up, therapy failure was defined as death or a relapse of tuberculosis.nnnRESULTSnPlasma concentrations below the normal ranges were frequently observed: isoniazid in 71%, rifampicin in 58%, ethambutol in 46%, pyrazinamide in 10% and both isoniazid and rifampicin in 45% of the patients. The plasma concentrations of isoniazid correlated inversely with the C-reactive protein level at the time of sampling (Pu200a=u200a0.001). During 1 year of follow-up, therapy failure occurred in five patients. Therapy failure occurred more frequently when the concentrations of isoniazid and rifampicin were both below the normal ranges (Pu200a=u200a0.013) and even more frequently when they were below the median 2 h drug concentrations obtained in the study (Pu200a=u200a0.005).nnnCONCLUSIONSnAt 2 h, plasma concentrations of isoniazid and rifampicin below the normal ranges were frequently observed. The inverse correlation between the plasma concentrations of isoniazid and C-reactive protein indicate a suboptimal treatment effect at standard dosing regimens. Dichotomization based on median 2 h drug concentrations was more predictive of outcome than dichotomization based on normal ranges.

Characteristics and Clinical Outcome of Bone and Joint Tuberculosis From 1994 to 2011: A Retrospective Register-based Study in Denmark

BACKGROUNDnMost information on bone-joint (BJ)-tuberculosis is based on data from high-incidence areas. We conducted a nationwide register-based analysis of BJ-tuberculosis in Denmark from 1994 to 2011.nnnMETHODSnWe linked data from the national tuberculosis surveillance system on BJ-tuberculosis, hospital records, the Danish Hospital and Civil Registration System.nnnRESULTSnWe identified 282 patients with BJ-tuberculosis, 3.6% of all tuberculosis cases (n = 7936). Spinal tuberculosis was found in 153 of 282 patients (54.3%); 83.3% of all cases were immigrants. Danes were older and had higher Charlson comorbidity index scores than immigrants (P < .01). C-reactive protein and erythrocyte sedimentation rates were elevated in most cases. Median time to diagnosis after first hospital contact was 19.5 days for spinal tuberculosis and 28 days for other forms of BJ-tuberculosis (P = .01). Of patients with spinal tuberculosis, 54/133 (40.6%) had neurologic deficits at admission and 17.3% presented with cauda equina. Diagnosis was culture verified in 87%. (Resistance to any drug was found in 10.2%). Median time on antituberculous treatment for patients with spinal and other forms of BJ-tuberculosis was 9 months and 7 months, respectively (P < .01). Surgery was required in 44.4% patients with spinal tuberculosis and in 32.6% patients with other forms of BJ-tuberculosis (P = .04). Sequelae were reported in 57.5% of patients with spinal tuberculosis and 29.1% of patient with other forms of BJ-tuberculosis (P < .01). One-year mortality was 25.5% among Danes compared with 1.3% among immigrants (P < .01).nnnCONCLUSIONSnBJ-tuberculosis was rare and seen mainly in younger immigrants in Denmark. More than half of cases were spinal tuberculosis, presenting with more severe symptoms and worse outcome, compared with other forms of BJ-tuberculosis.

Bedside Evaluation of Cerebral Energy Metabolism in Severe Community-Acquired Bacterial Meningitis

BackgroundMortality and morbidity have remained high in bacterial meningitis. Impairment of cerebral energy metabolism probably contributes to unfavorable outcome. Intracerebral microdialysis is routinely used to monitor cerebral energy metabolism, and recent experimental studies indicate that this technique may separate ischemia and non-ischemic mitochondrial dysfunction. The present study is a retrospective interpretation of biochemical data obtained in a series of patients with severe community-acquired meningitis.MethodsCerebral energy metabolism was monitored in 15 patients with severe community-acquired meningitis utilizing intracerebral microdialysis and bedside biochemical analysis. According to previous studies, cerebral ischemia was defined as lactate/pyruvate (LP) ratio >30 with intracerebral pyruvate level <70xa0µmolxa0L−1. Non-ischemic mitochondrial dysfunction was defined as LP-ratio >30 at a normal or increased interstitial concentration of pyruvate (≥70xa0μmolxa0L−1). Patients with LP-ratios <30 were classified as no mitochondrial dysfunction.ResultsThe biochemical pattern was in 8 patients (10 microdialysis catheters) classified as no mitochondrial dysfunction, in 5 patients classified as non-ischemic mitochondrial dysfunction, and in 2 patients (3 catheters) classified as ischemia.ConclusionsIn patients with severe community-acquired meningitis, compromised cerebral energy metabolism occurs frequently and was diagnosed in 7 out of 15 cases. A biochemical pattern of non-ischemic mitochondrial dysfunction appears to be a more common underlying condition than cerebral ischemia.

Use of intracranial pressure monitoring in bacterial meningitis: a 10-year follow up on outcome and intracranial pressure versus head CT scans

Abstract Background: The aim of this study was to evaluate the clinical outcome of patients with severe bacterial meningitis where intracranial pressure (ICP) monitoring has been performed. Methods: A retrospective observational study including patients admitted 1st. January 2005 to 31st. December 2014. Thirty nine patients age 18–89 years were included. All the patients received intensive care with mechanical ventilation, ICP monitoring, sedation, antibiotics and corticosteroids according to current guidelines. Clinical outcome was defined as death during hospitalization or survival at hospital discharge. Results: The most common pathogen was Streptococcus pneumoniae (26; 67%). Thirteen patients died (33%) and neurologic impairment was noted in twenty two (84.6%) surviving patients. In S. pneumoniae cases patients with adverse outcome were significantly older (pu2009=u20090.0024) and immunosuppressed (pu2009=u20090.034). Lower mean-cerebral perfusion pressure (CPP) was found to correlate with adverse outcome (pu2009=u20090.005). Cerebrospinal fluid (CSF) was drained in fourteen patients. Increased ICP (>20u2009mmHg) was observed in twenty four patients. No significant correlation was found between measured ICP and head CT scans with signs of elevated ICP. Conclusions: Patients with severe meningitis should be admitted to intensive care units and evaluated for ICP monitoring regardless of head CT findings.

Inflammation-Induced Changes in Circulating T-Cell Subsets and Cytokine Production During Human Endotoxemia

Observational clinical studies suggest the initial phase of sepsis may involve impaired cellular immunity. In the present study, we investigated temporal changes in T-cell subsets and T-cell cytokine production during human endotoxemia. Endotoxin (Escherichia coli lipopolysaccharide 4 ng/kg) was administered intravenously in 15 healthy volunteers. Peripheral blood and bronchoalveolar lavage fluid (BALF) were collected at baseline and after 2, 4, 6, 8, and 24 hours for flow cytometry. CD4+CD25+CD127lowFoxp3+ regulatory T cells (Tregs), CD4+CD161+ cells, and activated Human leukocyte antigen, HLA-DR+CD38+ T cells were determined. Ex vivo whole-blood cytokine production and Toll-like receptor (TLR)-4 expression on Tregs were measured. Absolute number of CD3+CD4+ (P = .026), CD3+CD8+ (P = .046), Tregs (P = .023), and CD4+CD161+ cells (P = .042) decreased after endotoxin administration. The frequency of anti-inflammatory Tregs increased (P = .033), whereas the frequency of proinflammatory CD4+CD161+ cells decreased (P = .034). Endotoxemia was associated with impaired whole-blood production of tumor necrosis factor-α, interleukin-10, IL-6, IL-17, IL-2, and interferon-γ in response to phytohaemagglutinin but did not affect TLR4 expression on Tregs. No changes in the absolute count or frequency of BALF T cells were observed. Systemic inflammation is associated with lymphopenia, a relative increase in the frequency of anti-inflammatory Tregs, and a functional impairment of T-cell cytokine production.

Human pegivirus detected in a patient with severe encephalitis using a metagenomic pan-virus array

n Abstractn n We have used a metagenomic microarray to detect genomic RNA from human pegivirus in serum and cerebrospinal fluid from a patient suffering from severe encephalitis. No other pathogen was detected. HPgV in cerebrospinal fluid during encephalitis has never been reported before and its prevalence in cerebrospinal fluid needs further investigation.n n

Genomic Epidemiology of a Major Mycobacterium tuberculosis Outbreak: Retrospective Cohort Study in a Low-Incidence Setting Using Sparse Time-Series Sampling

Since 1992, Denmark has documented the largest outbreak of tuberculosis in Scandinavia ascribed to a single genotype, termed C2/1112-15. As of spring 2017, the International Reference Laboratory of Mycobacteriology in Copenhagen has collected and identified isolates from more than a thousand cases belonging to this outbreak via routine mycobacterial interspersed repetitive units-variable number of tandem repeats typing. Here, we present a retrospective analysis of the C2/1112-15 dataset, based on whole-genome data from a sparse time series consisting of 5 randomly selected isolates from 23 years of sampling. Even if these data are derived from only 12% of the collected isolates, we have been able to extract important key information, such as mutation rate and conserved single-nucleotide polymorphisms to identify discrete transmission chains, as well as the possible historical origins of the outbreak.

Simultaneous quantification of isoniazid, rifampicin, ethambutol and pyrazinamide by liquid chromatography/tandem mass spectrometry

A remediable cause of poor treatment response in drug‐susceptible tuberculosis (TB) patients may be low plasma levels of one or more of the first‐line anti‐TB drugs. The aim of this work was to develop an accurate and precise LC‐MS/MS method for simultaneous quantification of all four first‐line anti‐TB drugs in plasma suitable for therapeutic drug monitoring (TDM). To adjust for degradation and losses during sample preparation, isotopically labeled compounds were used as internal standards. Plasma samples spiked with internal standards were extracted using protein precipitation with methanol and acetonitrile. Simultaneous separation of all four drugs was accomplished with a Chromolith Reversed‐Phase column and mobile phases consisting of water, methanol, ammonium acetate and formic acid with subsequent mass spectrometric quantification. The linear range of the calibration curve for isoniazid was 0.5–10 mg/L, for rifampicin 0.75–30 mg/L, for ethambutol 0.25–10 mg/L and for pyrazinamide 4–80 mg/L. The lower limit of quantification was 0.5 mg/L, 0.75 mg/L, 0.25 mg/L and 4.0 mg/L, respectively. Precision estimated by the coefficient of variation was <15% for all four drugs. The LC‐MS/MS method can readily be used for simultaneous quantification of first‐line anti‐TB drugs in plasma and is well suited for TDM.

A Major Mycobacterium tuberculosis outbreak caused by one specific genotype in a low-incidence country: Exploring gene profile virulence explanations

Denmark, a tuberculosis low burden country, still experiences significant active Mycobacterium tuberculosis (Mtb) transmission, especially with one specific genotype named Cluster 2/1112–15 (C2), the most prevalent lineage in Scandinavia. In addition to environmental factors, antibiotic resistance, and human genetics, there is increasing evidence that Mtb strain variation plays a role for the outcome of infection and disease. In this study, we explore the reasons for the success of the C2 genotype by analysing strain specific polymorphisms identified through whole genome sequencing of all C2 isolates identified in Denmark between 1992 and 2014 (nu2009=u2009952), and the demographic distribution of C2. Of 234 non-synonymous (NS) monomorphic SNPs found in C2 in comparison with Mtb reference strain H37Rv, 23 were in genes previously reported to be involved in Mtb virulence. Of these 23 SNPs, three were specific for C2 including a NS mutation in a gene associated with hyper-virulence. We show that the genotype is readily transmitted to different ethnicities and is also found outside Denmark. Our data suggest that strain specific virulence factor variations are important for the success of the C2 genotype. These factors, likely in combination with poor TB control, seem to be the main drivers of C2 success.

Quantitative B-lymphocyte deficiency and increased TCRγδ T-lymphocytes in acute infectious spondylodiscitis

Acute infectious spondylodiscitis (AIS) is a serious infection of the spine with rising incidence and a mortality of 3–6%. The role of the immune system in AIS is largely unknown. We performed extensive B and T-lymphocyte phenotyping in patients with AIS at diagnosis and after treatment cessation. In this prospective multicentre study, flow cytometric analysis of T and B-lymphocyte subsets was performed in 35 patients at diagnosis and 3 months after treatment cessation. We additionally analysed levels of immunoglobulins and IgG subclasses, serum level and genetic variants of mannose-binding lectin, and somatic hypermutation. A total of 22 (61%) patients had B-lymphocytes below reference limit at baseline, persisting in 7 (30%) patients at follow-up. We found a lower proportion of CD19u2009+u2009CD27u2009+u2009IgD+ marginal zone B-lymphocytes and a higher proportion of γδ+ T-lymphocyte receptors compared with controls at both time points. Immunoglobulin levels were elevated at baseline compared to follow-up, and not associated with absolute B-lymphocyte count. In conclusion, a large proportion of AIS patients presented with profound B-lymphocyte deficiency, only partly reversible at follow-up. Identification of immune dysfunction related to AIS may allow for future targeted therapeutic interventions to restore host immunity.