Upper and lower respiratory airway complaints among female veterinary staff

Objective

Working with animals is characterized by exposure to particulate, biological or chemical matter, and respiratory complaints are common. The aim of our cross-sectional study was to assess the prevalence of respiratory symptoms and diagnoses among veterinary staff.

Methods

Participants working in veterinary practices were examined and a detailed questionnaire was used to collect data. IgE tests to common and animal allergens were performed to specify sensitization. Associations with respiratory outcomes were analysed using logistic regression models while controlling for potential confounders.

Results

Atopy was seen in 31% of the 109 female participants. Symptoms of rhinoconjunctivitis were the most frequent complaints (n = 92; 84%). In 18% the diagnosis was confirmed by physicians. Symptoms of upper and lower airways were highly correlated and an asthma diagnosis was confirmed in 11% of participants. Modelling revealed that sensitization against cats/dogs was a significant risk factor for respiratory symptoms of upper [odds ratio (OR) 4.61; 95% confidence interval (CI) 1.13–18.81] and lower airways (OR 5.14; 95% CI 1.25–21.13), physician-confirmed rhinoconjunctivitis (OR 13.43; 95% CI 1.69–106.5) and asthma (OR 9.02; 95% CI 1.16–70.39) in assistant staff of small-animal practices.

Conclusions

In several cases, rhinoconjunctivitis worsened after entering the profession. Atopy and specific sensitization to cats/dogs were risk factors for health impairments. Thus, to implement preventive measures, veterinary practice staff should be educated that upper respiratory tract symptoms are not harmless and should be diagnosed and treated early.

Discrimination Between Atopic, Allergic, and Asthmatic Volunteers for Human Exposure Studies on Sensory Irritation

Atopic, allergic, and especially asthmatic subjects might be particularly susceptible to sensory irritation induced by airborne chemicals compared to healthy individuals. Therefore, a good characterization of subjects is essential in inhalation exposure studies on sensory irritants. A total of 105 volunteers, 87% of whom reported to be non-allergic, participated in a medical examination that included skin prick test (SPT), measurements of total IgE, specific IgE (sIgE) to an ubiquitous allergen mix (sx1), and fractionated exhaled nitric oxide (FeNO), as well as pulmonary function and methacholine test. The median value of sIgE to sx1 was 0.20 kU/L (0.07-91.3 kU/L) and correlated significantly with total IgE (28.8 kU/L (2-756 kU/L)) and FeNO (14 ppb (5-100 ppb)). Forty-three subjects (41%) had sIgE to sx1 ≥ 0.35 kU/L and were classified as atopic. Thirty-five subjects, all also sx1-positive, were positive in SPT. Obstruction, small airway disease, and/or bronchial hyperreactivity were diagnosed in 18 subjects. Receiver operating characteristics (ROC) were performed to check whether signs of sensitization are useful to discriminate subjects with and without airway diseases. However, sx1, total IgE, FeNO, and SPT reached only low areas under the curve (AUC: 0.57-0.66). Although predominantly young and, according to their own statements, mostly non-allergic subjects participated in the study, almost half of them were atopic, and 10% had airway disease or bronchial hyperreactivity. This indicates that the validity of self-reported data might be inaccurate. In summary, diversified investigations of the allergy-related health status appear necessary for a thorough characterization of subjects for exposure studies on sensory irritants.

Impact of Internal and External Factors on EBC-pH and FeNO Changes in Humans Following Challenge with Ethyl Acrylate

Acute effects of ethyl acrylate exposure at 5 ppm for 4 h include changes of pH in exhaled breath condensate (EBC-pH) and exhaled nitric oxide (FeNO). So far, few data have been reported for atopic persons or the impact of the exposure conditions on biomarkers, e.g., constant versus variable application of irritants. Nine atopic and eighteen healthy volunteers without bronchial hyperresponsiveness were exposed for 4 h to ethyl acrylate concentrations of 0.05 ppm (sham), 5 ppm (constant concentration), and 0-10 ppm (variable, mean concentration of 5 ppm) in an exposure laboratory. A positive atopic status was defined according to specific IgE concentrations to common inhalant allergens (sx1 ≥ 0.35 kU/L). Biomarker levels were assessed before and after challenge and adjusted for levels after sham exposure (net response). Ethyl acrylate at constant, but not at variable concentrations induced a significant change in the net responses of EBC-pH and FeNO. Concerning FeNO, this could be observed only for atopic persons. The changes of biomarker levels were related to their baseline values. Biomarker responses to challenge with ethyl acrylate may be influenced by the patterns of application as well as baseline airway inflammation and atopic status of the volunteers.

Prevalence of work-related rhino-conjunctivitis and respiratory symptoms among domestic waste collectors

Waste collectors may suffer from acute and chronic health effects caused by organic dust (bioaerosols). Pathophysiological symptoms may originate either from allergic or irritative pathomechanisms, but an explicit distinction of the etiology is often complicated although crucial for proper risk assessment and workplace prevention. In this cross-sectional study, a total of 69 male waste collectors from the Ruhr area in Germany underwent a customized testing protocol including a modified questionnaire, basic clinical examination, spirometry, and immunologic parameters. Subjects were classified according to their work tasks into loaders (n=27), floaters (n=29), and drivers (n=13). We found that a high percentage of the workers had complaints (eyes 29.0%, nose 39.1%, and cough 34.8%) which were strongly work-related. Multiple logistic regression analyses indicated that duration of employment in waste collection (per 10 years) was associated with an increased prevalence of cough (OR=1.64, 95% CI 0.81; 3.35) and chronic bronchitis (OR=2.18, 95% CI 0.80; 5.92). An association between rhinitis and cough (OR=2.62, 95% CI 0.94; 7.27) was found, which supports the association between the prevalence of upper and lower airway disease. Furthermore, when adjusting for smoking status, atopic subjects suffered more frequently from irritation of the lower airways as indicated by cough (OR=2.71, 95% CI 0.91; 8.08). In conclusion, the study demonstrates associations between the prevalence of upper and lower airway disease in waste collectors. Notably, an underlying allergic disease in waste collectors could be suspected more commonly than previously reported.

Effects of Exposure to Welding Fume on Lung Function: Results from the German WELDOX Study

The association between exposure to welding fume and chronic obstructive pulmonary disease (COPD) has been insufficiently clarified. In this study we assessed the influence of exposure to welding fume on lung function parameters. We investigated forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), FEV1/FVC, and expiratory flow rates in 219 welders. We measured current exposure to respirable particles and estimated a worker's lifetime exposure considering welding techniques, working conditions and protective measures at current and former workplaces. Multiple regression models were applied to estimate the influence of exposure to welding fume, age, and smoking on lung function. We additionally investigated the duration of working as a welder and the predominant welding technique. The findings were that age- and smoking-adjusted lung function parameters showed no decline with increasing duration, current exposure level, and lifetime exposure to welding fume. However, 15% of the welders had FEV1/FVC below the lower limit of normal, but we could not substantiate the presence of an association with the measures of exposure. Adverse effects of cigarette smoking were confirmed. In conclusion, the study did not support the notion of a possible detrimental effect of exposure to welding fume on lung function in welders.

Cellular and Soluble Inflammatory Markers in Induced Sputum of Composting Plant Workers

Inflammatory processes, including respiratory symptoms, can be induced among workers in composting plants exposed to bioaerosols containing microorganisms and their compounds. We evaluated inflammatory processes in the lower respiratory tract via cellular and soluble mediator profiles in induced sputum (IS). IS samples of 140 current (35% smokers) and 49 former compost workers (29% smokers) as well as 29 white-collar workers (17% smokers) were collected and analyzed for the cell count and composition, and for soluble biomarkers. Significant differences between current and former compost workers and white-collar workers were detected for total cell count (p=0.0004), neutrophils (p=0.0045), sCD14 (p=0.008), and 8-isoprostane (p<0.0001). IS of non-smoking former compost workers showed lower concentrations of IL-8, total protein, immunoreactive MMP-9 and sCD14, compared with non-smoking current compost workers. 10.1% of the study population was suffering from chronic bronchitis with significant differences (p=0.018) between former compost workers (24.5%), current workers (5%), and white-collar workers (10.3%). Significantly lower IL-8 (p=0.0002), neutrophils (p=0.001), and MMP-9 (p=0.0023) values were measured in healthy subjects compared with subjects with chronic bronchitis. In conclusion, changes in lower airways were detected by analysis of biomarkers in IS of current exposed and, to a lesser extent, in IS of former compost workers. These effects are especially pronounced in subjects with chronic bronchitis.

Leukotriene B4, 8-iso-prostaglandin F2 alpha, and pH in exhaled breath condensate from asymptomatic smokers

Long-term cigarette smoking is the major etiological factor for the development of chronic obstructive pulmonary disease (COPD). Airway inflammation and oxidative stress are implicated in the pathogenesis. Biomarkers reflecting these responses could be analyzed in exhaled breath condensate (EBC). Recently, it became obvious that mediator concentrations in EBC could be influenced by age of the subjects, equipment, sampling properties, and the analytical assays applied. In the present study we evaluated 8 smokers (20-56 yr) and 16 non-smoking adults (18-60 yr) with normal spirometry and no episode of airway infection during 6 weeks prior to the study. EBC samples were obtained with the commercial device ECoScreen2 at a controlled temperature of -20 degrees C. Leukotriene B(4) (LTB(4), marker of inflammation), 8-iso-prostaglandin F(2 alpha) (8-iso-PGF(2 alpha)/8-isoprostane, oxidative stress) concentrations, and pH were measured. With 10 min of tidal breathing, a lower EBC volume was collected in smokers (median 1.22 ml; interquantil range 1.06-1.74 ml) than in non-smokers (1.6 ml; 1.16-2.21 ml; P=0.06). Significant differences were found in pH in smokers compared with non-smokers (7.14 (5.70-7.43) vs. 7.59 (7.28-7.73); P<0.01). No significant differences were observed in EBC concentrations of LTB(4) or 8-iso-PGF(2 alpha). The study demonstrates that acidopnea is detectable in otherwise asymptomatic smokers and might precede changes in the level of arachidonic acid metabolites. For pH is considered to be the most validated marker determined in EBC samples, it may be useful for screening asymptomatic individuals for smoking-induced early airway damage.

[EBC: a new matrix for assessment of airway and lung inflammation. Current aspects of environmental and occupational medicine]

For many environmental and occupational pollutants the respiratory system represents the route of entry. Inflammation is a fundamental process in the pathophysiological cascade leading to respiratory diseases such as asthma or chronic obstructive pulmonary disease. Non-invasive inflammatory monitoring may assist in the diagnosis as well as assessments of severity and response to treatment. Of these, exhaled nitric oxide is the best validated constituent and is used for assessing airway inflammation in clinical practice, particularly in patients with asthma. Exhaled breath condensate (EBC) is the liquid phase of the exhaled breath sampled by cooling. EBC, like blood or urine, is not a marker itself but a matrix in which a wide variety of substances have already been detected. EBC biomarkers reflect acid stress, oxidative stress, or inflammation. There are still many methodological limitations and the interpretation of findings is hampered by the fact that the most widely used devices differ significantly in their collection efficiency for markers of interest and the analytical technology employed is often near the limit of detection. In spite of promising data, standardisation of the already existing procedures is required for the implementation of EBC in clinical practice. EBC might be of particular interest in preventive medicine since adverse inflammatory processes often precede changes in lung function. Concerning the adverse effects of air pollution, there is a special focus on markers reflecting oxidative stress since air pollutants have the ability to drive free radical reactions. This overview focuses on recent data on EBC obtained from articles concerning applications of exhaled breath analysis in environmental and occupational medical research.

[DNA repair: from the mechanisms to the impact on occupational research]

The human genome comprises more than three billion base pairs and a part of this information is responsible for the control of cell proliferation. Different internal and external factors are able to affect DNA and could influence the proliferation process. As a consequence critical diseases may occur. To prevent such harmful occurrences, the human body contains multiple repair enzymes that allow for the immediate elimination of DNA damage. Since each individual exhibits a set of gene variants with different properties, each person possesses his/her individual spectrum of DNA repair gene variants. For this reason, the first step of current studies is to obtain more information about the impact of DNA variants in repair enzymes in connection with certain occupational exposures with the aim to use this information in epidemiological models to calculate in which manner such variants are able to modulate DNA adducts or biomonitoring parameters.

Exhaled breath condensate analysis: evaluation of a methodological setting for epidemiological field studies

The analysis of exhaled breath condensate (EBC) is a noninvasive method to determine airway inflammation. There is accumulating evidence that pH, nitrogen oxides (NOx), and leukotriene B4 (LTB4) are suitable markers of inflammatory airway diseases. It was the aim of the present pilot study to evaluate a protocol of EBC sampling and processing for epidemiologic field studies. EBC samples were repeatedly obtained by 16 healthy adults on each of four days over two consecutive weeks. The effects of sample collection (volume vs. time, with vs. without nose-clip) and sample processing on volume, pH, NOx, and LTB4 as well as within-day, between-day, and between-week reproducibility were assessed. We found that wearing a nose-clip had no significant effects on mediators. Sampling time was the major determinant of the volume. Reproducibility was fairly good. Storage at 4-6 degrees C for 24 h had no significant effects on NOx and LTB4 concentrations, but resulted in an increase of pH. In conclusion, wearing a nose-clip during EBC collection is not recommended in terms of convenience and compliance for repeated investigations. Samples for the analyses of NOx and LTB4 can be transported under usual conditions, but pH should preferably be determined at the workplace.

Azathioprine withdrawal in stable lung and heart/lung recipients receiving cyclosporine-based immunosuppression

BACKGROUND

Chronic rejection is the leading cause of graft failure after (heart-) lung transplantation. Therefore, many centers maintain a triple immunosuppressive cyclosporine-based regimen including azathioprine (AZA) during the long-term course after lung transplantation. However, an increased risk of malignancies has been attributed to prolonged immunosuppression, and there is evidence that less intensive immunosuppressive regimens are feasible in the long-term course after other solid organ transplantation. Therefore, we investigated the effects of AZA withdrawal in stable lung transplant recipients.

METHODS

A prospective study was performed to assess the effects of AZA withdrawal in patients who received a lung transplant more than 4 years ago with stable graft function defined by absence of rejection episodes for at least 2 years and no evidence of bronchiolitis obliterans.

RESULTS

A total of 24 patients qualified for the study and 7 discontinued AZA. Despite the small number of patients, termination of the study became necessary after 12 months because significantly more grafts showed deteriorating function after withdrawing AZA (4 of 7) compared to recipients continuing a triple therapy (1 of 17; P<0.05). In recipients with deteriorating graft function conventional treatment with high-dose corticosteroids and reinstitution of AZA failed to stop the development of obliterative bronchiolitis.

CONCLUSIONS

Our data reinforce the importance of a potent immunosuppressive regimen for the maintenance of stable graft function after lung transplantation.

Pulmonary hypertension after splenectomy?

BACKGROUND

A high prevalence of asplenia has been observed in patients with unexplained pulmonary hypertension.

OBJECTIVE

To describe the clinical and histopathologic characteristics of patients with postsplenectomy pulmonary hypertension and to compare the prevalence of surgical asplenia in patients with idiopathic pulmonary hypertension and patients with other pulmonary diseases.

DESIGN

Case series and case-control study.

SETTING

University hospital in Hannover, Germany.

PATIENTS

61 patients with pulmonary hypertension and 151 lung transplant recipients.

RESULTS

The prevalence of asplenia in patients with pulmonary hypertension was 11.5% (95% CI, 4.7% to 22.2%) compared with 0% (CI, 0% to 3.2%) in those without pulmonary hypertension (P < 0.001). Histopathologic examination of lung specimens from patients with postsplenectomy pulmonary hypertension showed intimal fibrosis, plexiform lesions, and abundant thrombotic lesions.

CONCLUSION

Patients who have had splenectomy may be at increased risk for developing pulmonary hypertension.

The high-affinity Fc gamma RI on PMN: regulation of expression and signal transduction

In this paper we report that interferon-gamma (IFN-gamma) maintains and enhances functional properties of terminally differentiated polymorphonuclear cells (PMN). Such effects are obvious when compared with untreated PMN declining in their functional response. Culture for 18 hr with 100 IU/ml of recombinant IFN-gamma resulted in the expression of about 15,000 Fc gamma RI per PMN. IFN-gamma maintained viability of PMN and prevented reduction of Fc gamma RIIIb caused by apoptosis. No alterations were found in the level of Fc gamma RIIa. Next, functional properties of Fc gamma RI were evaluated. Calcium mobilization was detected in fura-2/acetoxymethylester (AM)-loaded PMN using a spectrophotometer and the respiratory burst was measured as luminol-dependent chemiluminescence. Cross-linking of an F(ab')2 fragment of monoclonal antibody (mAb) 22.2 to Fc gamma RI gave similar results to those obtained with intact monomeric human immunoglobulin G (mhIgG) when subsequently cross-linked. Moreover, after blocking Fc gamma RIIa and Fc gamma RIIIb with respective mAb fragments, mhIgG was still effective in triggering a calcium flux demonstrating that second messenger generation was caused by Fc gamma RI engagement. Even though Fc gamma RI expression was lower than that of Fc gamma RIIa, Fc gamma RI induced a higher increase of the respiratory burst. In addition, the protein tyrosine phosphatase CD45 was able to inhibit both responses when it was co-cross-linked with CD64, suggesting involvement of tyrosine phosphorylation in early signalling steps.

The low affinity Fc gamma RIIa and Fc gamma RIIIb on polymorphonuclear neutrophils are differentially regulated by CD45 phosphatase

Stimulation of human polymorphonuclear neutrophils through ligation and cross-linking of the low affinity Fc gamma RIIa and Fc gamma RIIIb using mAb Fab and F(ab')2 fragments led to transient intracellular calcium mobilization and activation of the respiratory burst. Fc gamma RIIIb engagement resulted in a different pattern of intracellular calcium flux, and induction of the respiratory burst was significantly more effective than in the case of Fc gamma RIIa. These data demonstrate that the capacity of Fc gamma RIIIb to transduce transmembrane signals itself contributes to full cell activation. Treatment with a mAb F(ab')2 fragment recognizing CD45 phosphatase suppressed Fc gamma R-induced calcium mobilization in a dose-dependent manner. An ongoing intracellular calcium mobilization was immediately terminated when activation was followed by co-cross-linking Fc gamma R and CD45. This suggests that the initial steps of Fc gamma R signal transduction pathways are influenced by the state of tyrosine phosphorylation. Combined cross-linking of both receptors, however, was hardly susceptible to CD45. Also, inhibition of respiratory burst by CD45 in the case of Fc gamma RIIIb was minimal compared with that for Fc gamma RIIa. Signal transduction pathways of low affinity Fc gamma RIIa and Fc gamma RIIIb are differentially regulated by CD45, underlining the essential function of Fc gamma R-mediated tyrosine phosphorylation in polymorphonuclear neutrophil activation.

The low affinity Fc gamma RIIa and Fc gamma RIIIb on polymorphonuclear neutrophils are differentially regulated by CD45 phosphatase

Stimulation of human polymorphonuclear neutrophils through ligation and cross-linking of the low affinity Fc gamma RIIa and Fc gamma RIIIb using mAb Fab and F(ab')2 fragments led to transient intracellular calcium mobilization and activation of the respiratory burst. Fc gamma RIIIb engagement resulted in a different pattern of intracellular calcium flux, and induction of the respiratory burst was significantly more effective than in the case of Fc gamma RIIa. These data demonstrate that the capacity of Fc gamma RIIIb to transduce transmembrane signals itself contributes to full cell activation. Treatment with a mAb F(ab')2 fragment recognizing CD45 phosphatase suppressed Fc gamma R-induced calcium mobilization in a dose-dependent manner. An ongoing intracellular calcium mobilization was immediately terminated when activation was followed by co-cross-linking Fc gamma R and CD45. This suggests that the initial steps of Fc gamma R signal transduction pathways are influenced by the state of tyrosine phosphorylation. Combined cross-linking of both receptors, however, was hardly susceptible to CD45. Also, inhibition of respiratory burst by CD45 in the case of Fc gamma RIIIb was minimal compared with that for Fc gamma RIIa. Signal transduction pathways of low affinity Fc gamma RIIa and Fc gamma RIIIb are differentially regulated by CD45, underlining the essential function of Fc gamma R-mediated tyrosine phosphorylation in polymorphonuclear neutrophil activation.

[The motor response potential after distal and proximal stimulation: studies in healthy volunteers and in polyneuropathies (author's transl)]

Muscle responses evoked distally and proximally were recorded in median and in peroneal nerves from controls and patients with polyneuropathies of different origin. The following parameters were studied in the individual muscle response: 1. the amplitude of the potential, measured peak to peak, 2. the amplitude of the negative phase, 3. the total duration of the potential, 4. the duration of the negative phase, 5. the area covered by the negative phase. Results of the proximal measurements were divided by those of the distal records. Distal motor latencies and nerve conduction velocities were also determined. In controls a loss of amplitude of 10-15% and an equal reduction of the area covered by the negative phase was noted in proximally evoked responses and the duration of the negative phase was increased by 2-7% when compared with distal measurements. In some polyneuropathies these parameters showed significantly pathological changes, although distal motor latency, amplitude and nerve conduction velocity were still within the normal range. Comparison of distally and proximally evoked muscle potentials may thus lead to further information about the mode of conduction in altered motor nerves.