Fire simulator exposure alters the innate epithelial response and inflammatory status in the airways of firefighters.

BACKGROUND: Firefighters are often exposed to high temperatures and by-products of combustion, which can compromise their health. We aimed to evaluate the effect of fire exposure in fire simulators on the airways of firefighters at different time-points. METHODOLOGY: Thirty-seven male firefighters exposed to fire simulators were evaluated in three phases: pre-exposure, at the end of the first week, and 4 weeks after. Pulmonary function by spirometry, nasal mucociliary clearance; peripheral oxygen saturation, inflammatory markers in the nasal lavage and CC16 in the sputum, nasal obstruction, and quality of life (using the questionnaires NOSE and SNOT-22) were assessed. RESULTS: Higher levels of IL-8, IL-10, and exhaled carbon monoxide were found more in phase 2 than in phase 1. Higher CC16 levels and lower peripheral oxygen saturation were observed in phase 3 as compared to phase 1. Lower levels of IL-2 and peripheral oxygen saturation were found in phase 3 than in phase 2. Higher nasal mucociliary clearance, as well as the worst quality of life and nasal obstruction, were observed in phases 2 and 3 as compared to phase 1. CONCLUSIONS: The firefighters’ exposures to high temperatures and by-products of combustion in the fire simulators elicit an inflammatory process in the airways with impairment in the innate epithelial response of the upper airway lining. Furthermore, changes in O2 transport affected the professionals’ quality of life negatively.

Prospective open-label evaluation of long-term low-dose doxycycline for difficult-to-treat chronic rhinosinusitis with nasal polyps.

BACKGROUND: This study aimed to assess clinical outcomes of long-term low-dose oral doxycycline therapy in difficult-to-treat chronic rhinosinusitis with polyps (CRSwNP). METHODS: This was a prospective, open-label study of 60 patients with difficult-to-treat CRSwNP who had undergone endoscopic sinus surgery. Patients were divided into two groups: 28 received nasal steroids, saline irrigation, and doxycycline (200 mg on the first day, followed by 100 mg once daily) for 12 weeks, while 30 received only nasal steroids and saline irrigation. The main outcome measure was an adequate effect size of doxycycline treatment on clinically meaningful significant improvement of SNOT-20. Other outcome measures were the SNOT-20, NOSE, and Lund-Kennedy scores. The following parameters were also analyzed: asthma, rhinitis, non-steroidal-exacerbated respiratory disease (NERD), and baseline serum IgG, IgA, IgE, IgM, ANCA, and eosinophil count. RESULTS: There was an adequate effect size of doxycycline treatment on clinically meaningful significant improvement of SNOT-20. Patients who received doxycycline also had significantly better outcomes regarding SNOT-20, NOSE, and Lund-Kennedy scores. There was a negative association among a clinically significant improvement of SNOT-20 and presence of asthma, NERD, and elevated serum IgE levels before treatment. CONCLUSION: These findings suggest that doxycycline may have a beneficial role for CRSwNP patients, especially for patients without asthma, NERD or high levels of serum IgE before treatment.

Mechanical disfunction in the mucosal oedema formation of patients with nasal polyps.

BACKGROUND: Nasal polyposis (NP) is characterized by an anomalous tissue growth with oedema and a lack of extracellular matrix. In this study, we investigated whether a mechanical disfunction of the forces that act in oedema formation is present in NP. METHODS: We compared the interstitial hydrostatic pressure behaviour during a saline solution infusion between healthy nasal mucosa (inferior and middle turbinate from 10 patients) and inflamed nasal mucosa from NP patients (inferior, middle turbinate and a nasal polyp from 6 patients). We used Controlled Disc Stimulation equipment to compare the curve Pressure/Volume created during the saline solution infusion. RESULTS: The pressure at 0.2 ml infusion was lower in the middle turbinate of NP patients than in the middle turbinate of control patients. The lowest P/V mean assessed was in the polypoid tissue. CONCLUSIONS: The interstitial hydrostatic pressure showed different behaviour during liquid infusion in nasal mucosa from NP patients when compared with healthy nasal mucosa. This study allows us to cogitate on a new pathophysiological mechanism contributing to the development of the NP.

Evaluation of the Impact of Exposure To Heat and to By-Products of Combustion on the Health of Firefighters.

Firefighters are often exposed to high temperatures and by-products of combustion, which can affect their health. In this study, we assessed the impact of acute exposure of firefighters in fire simulators. Twenty male firefighters were exposed to fire simulators, and observed in four phases: pre-exposure (group 0, control) and after the end of the first (group 1), second (group 2), and fourth (group 3) weeks of training. Blood samples were collected and dosed to evaluate the response of the immune, inflammatory (C-reactive protein, IL6, and IL10), and endocrine systems (cortisone, total testosterone, free testosterone, SHBG, bioavailable testosterone, TSH, and free T4). In groups 0, 1, and 3, a thermographic evaluation was also carried out to study the temperature and body heat flow of the participants. Regarding the inflammatory process, an increase in C-reactive protein and a reduction in IL-10 were observed. With respect to hormonal markers, an increase in cortisol and reduced levels of free T4 and bioavailable testosterone were found after exposure, with recovery of testosterone levels in the final week of training. Thermoregulatory adaptation of the organism has been associated with changes in heat flow in the organism in people subjected to extreme temperatures, with emphasis on the performance of the lower limbs. Our findings demonstrate an inflammatory response with hormonal changes after exposure to fire and an adaptive response of thermal balance, which could aid understanding of the physiology of the human body in extreme situations.

Les sapeurs-pompiers (SP) sont régulièrement exposés à la chaleur et aux produits de combustion, qui peuvent avoir un retentissement sur leur santé. Nous avons évalué l'effet d'une exposition aiguë de 22 SP (tous des hommes) à incendie simulé grâce à la répétition à 4 reprises d'une même batterie d'examens (avant- T0, et à la fin des 1ère -T1 2ème - T2 et 3ème - T3 semaines d'entraînement). Des paramètres sanguins relatifs à l'inflammation et l'immunité (CRP, IL6, IL10) ainsi qu'au système endocrinien (cortisol, testostérones totale, libre et biodisponible, SHBG, TSH et T4 libre) étaient prélevés à chaque évaluation. Une étude thermographique, évaluant la température corporelle et le flux thermique corporel était réalisée à T0, T1 et T3. On constatait une augmentation de la CRP et une baisse de IL10. On observait une augmentation de la cortisolémie ainsi qu'une baisse de thyroxine libre et testostérone biodisponible, cette dernière se normalisant à T3. L'adaptation corporelle à la chaleur se traduit par une augmentation du flux thermique, en particulier aux membres inférieurs. Nous observons donc des réponses inflammatoire comme endocrinienne et une adaptation de la thermorégulation en cas d'exposition à un incendie, constatations pouvant contribuer à la compréhension de la physiologie humaine en situations extrêmes.

Role of imbalance of eicosanoid pathways and staphylococcal superantigens in chronic rhinosinusitis.

Chronic rhinosinusitis (CRS) is a multifactorial disease of the upper airways with a high prevalence (approximately 11%) in the general population. Different immune and inflammatory mechanisms are involved in its pathogenesis. Alterations in the arachidonic acid pathway (leading to an imbalanced production of eicosanoids) have been linked to the pathophysiology of different diseases especially nasal polyposis, asthma, and aspirin-exacerbated respiratory disease. Furthermore, viral and bacterial infections have been identified as important factors amplifying the pro-inflammatory reactions in these pathologies. This review summarizes the impact of an imbalance in the eicosanoid pathway and the effect of Staphylococcus aureus enterotoxins on the regulation of the pro-inflammatory network in CRS and their translation into disease severity.