Identification of late asthmatic reactions following specific inhalation challenge.

Unlabelled: Specific inhalation challenge (SIC) is the reference standard for the diagnosis of occupational asthma. Current guidelines for identifying late asthmatic reactions are not evidence based.

Objectives: To identify the fall in forced expiratory volume in 1 s (FEV) required following SIC to exceed the 95% CI for control days, factors which influence this and to show how this can be applied in routine practice using a statistical method based on the pooled SD for FEV from three control days.

Characteristics of hypersensitivity pneumonitis diagnosed by interstitial and occupational lung disease multi-disciplinary team consensus.

Introduction: The causes of hypersensitivity pneumonitis (HP) in the UK are changing as working practices evolve, and metalworking fluid (MWF) is now a frequently reported causative exposure. We aimed to review and describe all cases of HP from our UK regional service, with respect to the causative exposure and diagnostic characteristics.

Methods: In a retrospective, cross-sectional study, we collected patient data for all 206 cases of HP diagnosed within our UK-based regional NHS interstitial and occupational lung disease service, 2002-17.

Occupational asthma; the limited role of air-fed respiratory protective equipment.

Background: Evidence-based reviews have found that evidence for the efficacy of respiratory protective equipment (RPE) in the management of occupational asthma (OA) is lacking.

Aims: To quantify the effectiveness of air-fed RPE in workers with sensitizer-induced OA exposed to metal-working fluid aerosols in a car engine and transmission manufacturing facility.

Methods: All workers from an outbreak of metal-working fluid-induced OA who had continuing peak expiratory flow (PEF) evidence of sensitizer-induced OA after steam cleaning and replacement of all metal-working fluid were included.

Hospital Attendances and Acute Admissions Preceding a Diagnosis of Occupational Asthma.

Purpose: Occupational exposures are a common cause of adult-onset asthma; rapid removal from exposure to the causative agent offers the best chance of a good outcome. Despite this, occupational asthma (OA) is widely underdiagnosed. We aimed to see whether chances of diagnosis were missed during acute hospital attendances in the period between symptom onset and the diagnosis of OA.

Do laboratory challenge tests for occupational asthma represent what happens in the workplace?

Specific inhalation challenge (SIC) is the diagnostic reference standard for occupational asthma; however, a positive test cannot be considered truly significant unless it can be reproduced by usual work exposures. We have compared the timing and responses during SIC in hospital to Oasys analysis of serial peak expiratory flow (PEF) during usual work exposures.All workers with a positive SIC to occupational agents between 2006 and 2015 were asked to measure PEF every 2 h from waking to sleeping for 4 weeks during usual occupational exposures.

Understanding health beliefs and behaviour in workers with suspected occupational asthma.

Introduction: Long delays from symptom onset to the diagnosis of occupational asthma have been reported in the UK, Europe and Canada and workers are often reluctant to seek medical help or workplace solutions for their symptoms. Reducing this delay could improve workers' quality of life, and reduce the societal cost of occupational asthma. This study aimed to explore reasons behind such delays.

Hypersensitivity pneumonitis in workers exposed to metalworking fluids.

Background: This study used data from a large UK outbreak investigation, to develop and validate a new case definition for hypersensitivity pneumonitis due to metalworking fluid exposure (MWF-HP).

Methods: The clinical data from all workers with suspected MWF-HP were reviewed by an experienced panel of clinicians. A new MWF-HP Score was then developed to match the "gold standard" clinical opinion as closely as possible, using standard diagnostic criteria that were relatively weighted by their positive predictive value.

Do long periods off work in peak expiratory flow monitoring improve the sensitivity of occupational asthma diagnosis?

Introduction: Serial peak expiratory flow (PEF) monitoring is a useful confirmatory test for occupational asthma diagnosis. As weekends off work may not be long enough for PEF records to recover, this study investigated whether including longer periods off work in PEF monitoring improves the sensitivity of occupational asthma diagnosis.

Methods: Serial PEF measurements from workers with occupational asthma and from workers not at work during their PEF record, containing minimum data amounts and at least one rest period with > or = 7 consecutive days off work, were analysed.

Two variants of occupational asthma separable by exhaled breath nitric oxide level.

Unlabelled: Exhaled nitric oxide (FE(NO)) has been used as a marker of asthmatic inflammation in non-occupational asthma, but some asthmatics have a normal FE(NO). In this study we investigated whether, normal FE(NO) variants have less reactivity in methacholine challenge and smaller peak expiratory flow (PEF) responses than high FE(NO) variants in a group of occupational asthmatics.

Methods: We measured FE(NO) and PD(20) in methacholine challenge in 60 workers currently exposed to occupational agents, who were referred consecutively to a specialist occupational lung disease clinic and whose serial PEF records confirmed occupational asthma.

Serial lung function variability using four portable logging meters.

Objective: Portable lung function logging meters that allow measurement of peak expiratory flow (PEF) and forced expiratory volume in 1 second (FEV(1)) are useful for the diagnosis and exclusion of asthma. The aim of this study was to investigate the within and between-session variability of PEF and FEV(1) for four logging meters and to determine the sensitivity of meters to detect FEV(1) and PEF diurnal changes.

Methods: Thirteen assessors (all hospital staff members) were asked to record 1 week of 2-hour PEF and FEV(1) measurements using four portable lung function meters.

Diesel exhaust causing low-dose irritant asthma with latency?

Background: Diesel exhaust exposure may cause acute irritant-induced asthma and potentiate allergen-induced asthma. There are no previous reports of occupational asthma due to diesel exhaust.

Aims: To describe occupational asthma with latency in workers exposed to diesel exhaust in bus garages.

PEF analysis requiring shorter records for occupational asthma diagnosis.

Background: The Oasys programme plots serial peak expiratory flow (PEF) measurements and produces scores of the likelihood that the recordings demonstrate occupational asthma. We have previously shown that the area between the mean workday and rest day PEF curves [the area between the curves (ABC) score] has a sensitivity of 69% and specificity of 100% when plotted from waking time using a cut-off score of 15 l/min/h.

Aims: To investigate the minimum data requirements to maintain the sensitivity and specificity of the ABC score.

Functions of actin in endocytosis.

Endocytosis is a fundamental eukaryotic process required for remodelling plasma-membrane lipids and protein to ensure appropriate membrane composition. Increasing evidence from a number of cell types reveals that actin plays an active, and often essential, role at key endocytic stages. Much of our current mechanistic understanding of the endocytic process has come from studies in budding yeast and has been facilitated by yeast's genetic amenability and by technological advances in live cell imaging.

The WASP homologue Las17 activates the novel actin-regulatory activity of Ysc84 to promote endocytosis in yeast.

Actin plays an essential role in many eukaryotic cellular processes, including motility, generation of polarity, and membrane trafficking. Actin function in these roles is regulated by association with proteins that affect its polymerization state, dynamics, and organization. Numerous proteins have been shown to localize with cortical patches of yeast actin during endocytosis, but the role of many of these proteins remains poorly understood.

A new diagnostic score for occupational asthma: the area between the curves (ABC score) of peak expiratory flow on days at and away from work.

Background: Evidence-based guidelines recommend serial measurements of peak expiratory flow (PEF) on days at and away from work as the first step in the objective confirmation of occupational asthma. The aim of this study was to improve the diagnostic value of computer-based PEF analysis by using the program Oasys-2 to calculate a score from the area between the curves (ABC) of PEF on days at and away from work.

Methods: Mean 2-hourly PEFs were plotted separately for workdays and rest days for 109 workers with occupational asthma and 117 control asthmatics.