Airway Hyperresponsiveness to Methacholine in Chemical Warfare Victims

Abstract

Background: The lung is one of the most exposable organs to chemical warfare agents such as sulfur mustard gas. Pulmonary complications as a result of this gas range from severe bronchial stenosis to mild or no symptoms. Airway hyperresponsiveness (AHR) which is usually assessed as response to inhaled methacholine is the most characteristic feature of asthma. AHR is reported in chronic obstructive pulmonary disease patients and smokers, and may also show in chemical warfare victims. However, there are little reports regarding AHR in chemical warfare victims. Objective: Therefore, in this study, airway responsiveness to methacholine in victims of chemical warfare was examined. Methods: The threshold concentrations of inhaled methacholine required for a 20% change in forced expiratory flow in 1 s (FEV₁; PC₂₀) or a 35% change in specific airway conductance (PC₃₅) were measured in 15 chemical war victims and 15 normal control subjects. Results: In 10 out of 15 chemical warfare victims (two thirds), PC₂₀ and PC₃₅ methacholine could be measured and subjects were called responders. AHR to methacholine in responder chemical war victims (PC₂₀ = 0.41 and PC₃₅ = 0.82 g/l) was significantly lower than in normal subjects (PC₂₀ = 5.69 and PC₃₅ = 4.60 g/l, p < 0.001 for both cases). There was a significant correlation between FEV₁ and PC₂₀ methacholine (r = 0.688, p < 0.001). The correlations between PC₂₀ and PC₃₅ were statistically significant as well (r = 0.856, p < 0.001). Conclusion: Results showed increased airway responsiveness of most chemical warfare victims to methacholine which correlated with the FEV₁ value and which may be related to chronic airway inflammation or irreversible airway changes.

The effect of Nigella sativa alone, and in combination with dexamethasone, on tracheal muscle responsiveness and lung inflammation in sulfur mustard exposed guinea pigs

“…The most serious respiratory effects are observed at 14 days post-exposure (Eisenmenger et al, 1991). Emad and Rezaian (1997) and Emad et al (1995) have reported respiratory symptoms in 197 Iranian military veterans 10 years after receiving a single, high-concentration sulfur mustard exposure in 1986 during the Iraq-Iran conflict.The cause of increased tracheal responsiveness in SM exposed animals seen in the present study as well as those of previous studies in human (Mirsadraee et al, 2005;Boskabady et al, 2008b) is perhaps the Table 2 Values of differential count of WBC in sulfur mustard exposed (SME), SME treated with Nigella sativa and SME treated with Nigella sativa + dexamethasone guinea pigs (for each group, n = 4) and statistical differences between SME, SME treated with Nigella sativa and SME treated with Nigella sativa + dexamethasone groups.…”

“…Vijayaraghavan (1997) has reported a RD 50 (dose of sulfur mustard causing 50% decrease in respiratory rate) of 27.4 mg/m 3 of SM in mice exposed head only to the nebulized SM. Our previous studies have shown increased airway responsiveness to methacholine (Mirsadraee et al, 2005) and salbutamol (Boskabady et al, 2008a) in chemical war victims 17 years after exposing to SM during Iraq-Iran war. Eisenmenger et al (1991) have reported that the severity of respiratory tract involvement tended to be concentration-dependent.…”

ERK1/2 Signaling Pathway Modulates the Airway Smooth Muscle Cell Phenotype in the Rat Model of Chronic Asthma

“…Indeed, early studies on ASMC function focused on the contractile aspects to explain airway hyperreactivity, a characteristic of asthma in which airways exhibit an exaggerated response to a large number of different stimuli acting through many pathways [22,23,24]. This view, however, is rapidly changing because of the discovery that airway smooth muscles can undergo hyperplasia and/or hypertrophy, which can lead to structural changes in the airway obstruction and increased nonspecific airway hyperreactivity in chronic severe asthma [25, 26].…”

Complications and Carcinogenic Effects of Mustard Gas - a Systematic Review and Meta-Analysis in Iran

“…MG exposure usually is not fatal and also exposed individuals may not know immediately that they have been exposed, because MG may not have an odour or have an odour that might warn. Typically, signs and symptoms do not happen right away and depend on the severity of the exposure, symptoms and signs may not occur for up to 24 hours, which includes intense itching second-and third degree burns and skin irritation, which progressively turns into large blisters, which are very debilitating (Stuart et al, 2003;Kehe and Szinicz, 2005;Mirsadraee et al, 2005;Naraghi et al, 2005;Jabbari et al, 2012;Saleh et al, 2013;Mortazavi et al, 2014). Moreover many studies declared that this poison gas is carcinogenic both in animals and humans (Zandieh et al, 1990;Eisenmenger et al, 1991;Program, 2011).…”