Sophie Demarche

Comparison of the quantitative performances and measurement uncertainty estimates obtained during method validation versus routine applications of a novel hydrophilic interaction chromatography method for the determination of cidofovir in human plasma

Method validation is essential to ensure that an analytical method is fit for its intended purpose. Additionally, it is advisable to estimate measurement uncertainty in order to allow a correct interpretation of the results generated by analytical methods. Measurement uncertainty can be efficiently estimated during method validation as a top-down approach. However, method validation predictions of the quantitative performances of the assay and estimations of measurement uncertainty may be far away from the real performances obtained during the routine application of this assay. In this work, the predictions of the quantitative performances and measurement uncertainty estimations obtained from a method validation are compared to those obtained during routine applications of a bioanalytical method. For that purpose, a new hydrophilic interaction chromatography (HILIC) method was used. This method was developed for the determination of cidofovir, an antiviral drug, in human plasma. Cidofovir (CDV) is a highly polar molecule presenting three ionizable functions. Therefore, it is an interesting candidate for determination by HILIC mode. CDV is an acyclic cytidine monophosphate analog that has a broad antiviral spectrum and is currently undergoing evaluation in clinical trials as a topical agent for treatment of papillomavirus infections. The analytical conditions were optimized by means of design of experiments approach in order to obtain robust analytical conditions. These ones were absolutely necessary to enable the comparisons mentioned above. After a sample clean-up by means of solid phase extraction, the chromatographic analysis was performed on bare silica stationary phase using a mixture of acetonitrile-ammonium hydrogen carbonate (pH 7.0; 20mM) (72:28, v/v) as mobile phase. This newly developed bioanalytical method was then fully validated according to FDA (Food and Drug Administration) requirements using a total error approach that guaranteed that each future result will fall within acceptance limits of ±30% with a probability of 95% over a concentration range of 92.7-1020ng/mL. A routine application of the cidofovir determination in two pre-clinical trials demonstrated that the prediction made during the pre-study validation was consistent by retrospective analysis of the quality control (QC) samples. Finally, comparison of the measurement uncertainty estimations calculated from the method validation with those obtained from the routine application of the method was performed, stressing that the estimations obtained during method validation underestimated those obtained from routine applications and that the magnitude of this underestimation was function of the cidofovir concentration. Finally, this new HILIC method is reliable, easily applicable to routine analysis and transposable at low cost in other laboratories.

Detailed analysis of sputum and systemic inflammation in asthma phenotypes: are paucigranulocytic asthmatics really non-inflammatory?

BackgroundThe technique of induced sputum has allowed to subdivide asthma patients into inflammatory phenotypes according to their level of granulocyte airway infiltration. There are very few studies which looked at detailed sputum and blood cell counts in a large cohort of asthmatics divided into inflammatory phenotypes. The purpose of this study was to analyze sputum cell counts, blood leukocytes and systemic inflammatory markers in these phenotypes, and investigate how those groups compared with healthy subjects.MethodsWe conducted a retrospective cross-sectional study on 833 asthmatics recruited from the University Asthma Clinic of Liege and compared them with 194 healthy subjects. Asthmatics were classified into inflammatory phenotypes.ResultsThe total non-squamous cell count per gram of sputum was greater in mixed granulocytic and neutrophilic phenotypes as compared to eosinophilic, paucigranulocytic asthma and healthy subjects (p < 0.005). Sputum eosinophils (in absolute values and percentages) were increased in all asthma phenotypes including paucigranulocytic asthma, compared to healthy subjects (p < 0.005). Eosinophilic asthma showed higher absolute sputum neutrophil and lymphocyte counts than healthy subjects (p < 0.005), while neutrophilic asthmatics had a particularly low number of sputum macrophages and epithelial cells. All asthma phenotypes showed an increased blood leukocyte count compared to healthy subjects (p < 0.005), with paucigranulocytic asthmatics having also increased absolute blood eosinophils compared to healthy subjects (p < 0.005). Neutrophilic asthma had raised CRP and fibrinogen while eosinophilic asthma only showed raised fibrinogen compared to healthy subjects (p < 0.005).ConclusionsThis study demonstrates that a significant eosinophilic inflammation is present across all categories of asthma, and that paucigranulocytic asthma may be seen as a low grade inflammatory disease.

Biomarkers in the Management of Difficult Asthma

Difficult asthma is a heterogeneous disease of the airways including various types of bronchial inflammation and various degrees of airway remodeling. Therapeutic response of severe asthmatics can be predicted by the use of biomarkers of Type2-high or Type2-low inflammation. Based on sputum cell analysis, four inflammatory phenotypes have been described. As induced sputum is time-consuming and expensive technique, surrogate biomarkers are useful in clinical practice. Eosinophilic phenotype is likely to reflect ongoing adaptive immunity in response to allergen. Several biomarkers of eosinophilic asthma are easily available in clinical practice (blood eosinophils, serum IgE, exhaled nitric oxyde, serum periostin). Neutrophilic asthma is thought to reflect innate immune system activation in response to pollutants or infectious agents while paucigranulocytic asthma is thought to be not inflammatory and characterized by smooth muscle dysfunction. We currently lack of user-friendly biomarkers of neutrophilic asthma and airway remodeling. In this review, we summarize the biomarkers available for the management of difficult asthma.

Community pharmacists' evaluation of potentially inappropriate prescribing in older community-dwelling patients with polypharmacy: observational research based on the GheOP³S tool

Background In this study, we aimed to (i) determine the prevalence of potentially inappropriate prescribing (PIP) in community‐dwelling older polypharmacy patients using the Ghent Older Peoples Prescriptions community‐Pharmacy Screening (GheOP3S) tool, (ii) identify the items that account for the highest proportion of PIP and (iii) identify the patient variables that may influence the occurrence of PIP. Additionally, pharmacist‐physician contacts emerging from PIP screening with the GheOP3S tool and feasibility of the GheOP3S tool in daily practice were evaluated. Methods A prospective observational study was carried out between December 2013 and July 2014 in 204 community pharmacies in Belgium. Patients were eligible if they were (i) ≥70 years, (ii) community‐dwelling, (iii) using ≥5 chronic drugs, (iv) a regular visitor of the pharmacy and (v) understanding Dutch or French. Community pharmacists used a structured interview to obtain demographic data and medication use and subsequently screened for PIP using the GheOP3S tool. A Poisson regression was used to investigate the association between different covariates and the number of PIP. Results In 987 (97%) of 1016 included patients, 3721 PIP items were detected (median of 3 per patient; inter quartile range: 2‐5). Most frequently involved with PIP are drugs for the central nervous system such as hypnosedatives, antipsychotics and antidepressants. Risk factors for a higher PIP prevalence appeared to be a higher number of drugs (30% extra PIPs per 5 extra drugs), female gender (20% extra PIPs), higher body mass index (BMI, 20% extra PIPs per 10‐unit increase in BMI) and poorer functional status (30% extra PIPs with 6‐point increase). The feasibility of the GheOP3S tool was acceptable although digitalization of the tool would improve implementation. Despite detecting at least one PIP in 987 patients, only 39 physicians were contacted by the community pharmacists to discuss the items. Conclusion A high prevalence of PIP in community‐dwelling older polypharmacy patients in Belgium was detected which urges for interventions to reduce PIP.

Is it possible to claim or refute sputum eosinophils ≥ 3% in asthmatics with sufficient accuracy using biomarkers?

The concept of asthma inflammatory phenotypes has proved to be important in predicting response to inhaled corticosteroids. Induced sputum, which has been pivotal in the development of the concept of inflammatory phenotypes, is however not widely available. Several studies have proposed to use surrogate exhaled or blood biomarkers, like fractional exhaled nitric oxide (FENO), blood eosinophils and total serum immunoglobulin E (IgE). However, taken alone, each of these biomarkers has moderate accuracy to identify sputum eosinophilia. Here, we propose a new approach based on the likelihood ratio to study which thresholds of these biomarkers, taken alone or in combination, were able to rule in or rule out sputum eosinophils ≥3%. We showed in a large population of 869 asthmatics that combining FENO, blood eosinophils and total serum IgE could accurately predict sputum eosinophils ≥ or <3% in 58% of our population.

Time for reasoning ICS prescription in obstructive airway diseases

It is time to better target the patients with chronic obstructive airway diseases who really benefit from a chronic treatment with inhaled corticoids Inhaled corticoids (ICS) are powerful drugs to combat airway inflammation that have revolutionised the management of obstructive airway diseases and particularly that of asthma (1). Given the high prevalence of chronic obstructive airway diseases, ICS have become one of the most prescribed drugs worldwide. Although putting subjects at lower risk of undesirable side effects than systemic corticosteroids, ICS may not be entirely safe when used at high dosage. In this issue of the journal Chung et al. shows that, in a population-based study conducted in Taiwan over more than 30,000 people, the risk of TB is linearly correlated with the dose of inhaled corticoids. Overall ICS use caused a 2.04-fold increased risk of developing TB. Interestingly, it appeared from this study that high doses of ICS place the patient at a risk level (OR 2.32) similar to that found in those receiving disease modifying anti-rheumatic drugs such as anti-TNFα (2). Chungs study actually confirms another recent cohort study conducted in South Korea from a large database of the Health Insurance Review and Assessment Service although the risk was somewhat lower in the latter with an odd ratio for TB diagnosis of 1.2 in those receiving ICS whichever the underlying obstructive disease (3). These findings somehow contrasted with those of another large cohort study from Taiwan that has shown COPD itself as a risk factor for TB but has not confirmed the link between TB and ICS use in COPD patients (4). If most of the studies published so far have come from Asian countries with intermediate-to-high TB incidence, the same relationship was shown in a low TB country. In a population-based study from Canada Brassard et al. found a relative risk for TB of 1.48 among non-users of oral corticoids up to 1.95 for those receiving high dose equivalent to fluticasone 1000 µg/day (5). Tuberculosis is not the only respiratory infection that may be favoured by ICS usage. The first alert on the link between ICS and lower respiratory tract infection actually came from the TORCH study (Towards a Revolution in COPD Heath), a randomised controlled trial looking the effect of ICS and LABA on COPD mortality (6). In this study, the authors showed that 1000 µg/24 h fluticasone was associated with an increased risk of pneumonia compared with placebo or LABA (even if pneumonia was not ascertained by chest X ray in all cases). In keeping with this is the recent warning from a retrospective population-based study conducted in Scandinavia that shows an increased risk of pneumonia and hospitalisation in patients receiving high dose (783 µg/day) inhaled fluticasone, compared with those receiving moderate dose of budesonide (568 µg/day) (7,8). Furthermore, a recent COPD cohort study from Canada using Quebec Health Insurance Databases has shown an increased risk of 69% to develop serious pneumonia among patients currently using ICS. Even if the authors found it was a class effect, the risk was particularly elevated and dose related with fluticasone (9). It is, of course, not to say that ICS are useless in COPD. Early studies with high dose of fluticasone showed a reduction in exacerbation and the rate of decline in health (10,11). However, no convincing dose ranging studies have been published to support that these effects might not have been achieved by lower dose of ICS. A recent cross-sectional multi-centre study conducted in Belgium/Luxemburg has shown that 75% of COPD followed by chest physicians in clinical practice were receiving regular ICS, often at high dose, although nearly half of them were GOLD stage 2 (12). Clearly, usage of ICS in COPD in clinical practice goes well over the currently recommended GOLD guidelines that limit the prescription to those with severely impaired FEV1 (< 50% predicted) and recurrent exacerbations. On the other hand, the benefit of ICS in COPD is likely to be related to the presence of an eosinophilic airway inflammation, which is present in up to 30-40% of stable COPD (13). Indeed, management strategy that aims to minimise eosinophilic airway inflammation with corticosteroids is associated with a reduction in severe exacerbation (14). It is also important to bear in mind that roughly 20-30% stable COPD are colonised by potentially pathogens microorganisms (PPM) when assessed by routine culture (15) but this figure can raise to 57% when PCR is performed (16). We also know that exacerbations of COPD are mainly driven by acute airway infection (15). Although it is has not been demonstrated yet, it is conceivable that COPD whose airways are

Step-down of inhaled corticosteroids in non-eosinophilic asthma: A prospective trial in real life

While non‐eosinophilic asthmatics are usually considered poorly responsive to inhaled corticosteroids (ICSs), studies assessing a step‐down of ICS in this specific population are currently lacking.

Effectiveness of inhaled corticosteroids in real life on clinical outcomes, sputum cells and systemic inflammation in asthmatics: a retrospective cohort study in a secondary care centre

Objectives The impact of inhaled corticosteroids (ICS) on eosinophilic inflammation in asthma is well established, but their effect in a real-life setting has not been extensively studied. Our purpose was to investigate the effect of ICS on airway and systemic inflammation as well as on clinical outcomes in patients with asthma from clinical practice. Design, setting and participants We conducted a retrospective analysis on asthmatics from a secondary care centre in whom ICS were initiated/increased (n=101), stopped/decreased (n=60) or remained stable (n=63, used as a control group) between two visits with available sputum and blood cell counts. Results The median time between both visits ranged from 1 to 2 years. Initiating or increasing ICS (median variation (IQR): 800 (400–1200) µg beclomethasone equivalent dose per day) reduced sputum eosinophils and fractional exhaled nitric oxide (P<0.0001) and to a lesser extent blood eosinophils (P<0.0001), while withdrawing or decreasing ICS (median variation (IQR): 900 (500–1200) µg beclomethasone equivalentdose per day) resulted in increased sputum eosinophils (P=0.008). No change was found in patients with a stable dose. The effectiveness of ICS in improving asthma control, quality of life, forced expiratory volume in 1 s (FEV1), bronchial hyper-responsiveness and exacerbation rate was only observed in the eosinophilic phenotype (sputum eosinophils ≥3%, n=79). In non-eosinophilic asthmatics, stepping-down ICS resulted in an improvement in asthma control and quality of life, without any significant change in FEV1 (n=38). Conclusions Our results confirm the effectiveness of ICS on eosinophilic inflammation in real life and demonstrate that their clinical benefit seems to be restricted to eosinophilic asthmatics. Our data also support a try for stepping-down ICS in non-eosinophilic asthmatics.

A historical perspective: Are inhaled corticoids sufficient to control asthma?

Abstract Inhaled corticoids (ICS) made a dramatic breakthrough in the management of asthma in the late eighties resulting in a sharp reduction in morbidity and mortality in the following decades. Soon after, the association between ICS and long acting β2 agonists (LABA) soon became the gold standard of maintenance asthma treatment. With the advent of sputum induction it has become clear that asthma could not be considered as a unique entity but rather a display of several inflammatory phenotypes. Eosinophilic phenotype shows good response to ICS while non-eosinophilic, and in particular the neutrophilic phenotype, seems to be more resistant. Severe asthmatics show insufficient asthma control despite ICS/LABA. Those who are allergic and eosinophilic may benefit from add-on treatment with anti-IgE or anti-IL-5. Severe neutrophilic asthma could benefit from maintenance treatment with macrolides while thermoplasty offers some promise to those in whom airway smooth muscle hypertrophy contributes to disease instability

SELF-MEDICATION WITH OVER-THE-COUNTER ANALGESICS: A SURVEY OF PATIENT CHARACTERISTICS AND CONCERNS ABOUT PAIN MEDICATION

Pain is a common reason for self-medication with over-the-counter (OTC) analgesics. However, this self-treating population has remained largely uncharacterized. This cross-sectional observational study investigated individuals who self-medicate their pain with OTC analgesics to elucidate their pain characteristics and medication use. In addition, presence of and risk factors for concerns about pain medication were examined. The clinical profile of the participants (n = 1,889) was worse than expected with long-standing pain complaints (median pain duration of 9 years), pain located at multiple body sites (median of 4, and 13% with ≥10 painful body areas), about one-third suffering from daily pain and about 40% experiencing substantial pain-related disability. Head (58.6% of sample), low back (43.6%), and neck (30.7%) were the most common pain locations. About 73% had a physician diagnosis, mainly migraine and osteoarthritis. Paracetamol (used by 68.6% of patients) and nonsteroidal anti-inflammatory drugs (46.8%) were the most frequently used pain medications. About 40% of our sample showed substantial concern about the perceived need for pain medication and the perceived potential for harmful effects (eg, fear for addiction). These findings highlight the importance for health professionals to systematically probe pain patients about their self-medication practices and explore attitudes about pain medication. Perspective: This study found that the clinical picture of people who self-medicate their pain with OTC analgesics looked worse than expected. We also identified substantial concerns about pain medication. Therefore, we recommend that health professionals systematically probe pain patients about their self-medication practices and explore concerns about pain medication.