Oxidative stress in asthma: Part of the puzzle Sahiner, Umit M.; Birben, Esra; Erzurum, Serpil ...
Pediatric allergy and immunology,
December 2018, Letnik:
29, Številka:
8
Journal Article
Recenzirano
An imbalance between the production of reactive oxygen species and the capacity of antioxidant defense mechanisms favoring oxidants is called oxidative stress and is implicated in asthmatic ...inflammation and severity. Major reactive oxygen species that are formed endogenously include hydrogen peroxide, superoxide anion, hydroxyl radical, and hypohalite radical; and the major antioxidants that fight against the endogenous and environmental oxidants are superoxide dismutase, catalase, and glutathione. Despite the well‐known presence of oxidative stress in asthma, studies that target oxidative burden using a variety of nutritional, pharmacological, and environmental approaches have generally been disappointing. In this review, we summarize the current knowledge on oxidative stress and antioxidant imbalance in asthma. In addition, we focus on possible biomarkers of oxidative stress in asthma and on current and future treatment strategies using the modulation of oxidative stress to treat asthma patients.
The natural history of COVID‐19 caused by SARS‐CoV‐2 is extremely variable, ranging from asymptomatic or mild infection, mainly in children, to multi‐organ failure, eventually fatal, mainly in the ...eldest. We propose here the first model explaining how the outcome of first, crucial 10‐15 days after infection, depends on the balance between the cumulative dose of viral exposure and the efficacy of the local innate immune response (natural IgA and IgM antibodies, mannose‐binding lectin). If SARS‐CoV‐2 runs the blockade of this innate immunity and spreads from the upper airways to the alveoli in the early phases of the infections, it can replicate with no local resistance, causing pneumonia and releasing high amounts of antigens. The delayed and strong adaptive immune response (high‐affinity IgM and IgG antibodies) that follows, causes severe inflammation and triggers mediator cascades (complement, coagulation, and cytokine storm), leading to complications often requiring intensive therapy and being, in some patients, fatal. Low‐moderate physical activity can still be recommended. However, extreme physical activity and oral breathing with hyperventilation during the incubation days and early stages of COVID‐19 facilitates re‐inhalation and early direct penetration of high numbers of own virus particles in the lower airways and the alveoli, without impacting on the airway’s mucosae covered by neutralizing antibodies ("viral auto‐inhalation" phenomenon). This allows the virus to bypass the efficient immune barrier of the upper airway mucosa in already infected, young, and otherwise healthy athletes. In conclusion, whether the virus or the adaptive immune response reaches the lungs first is a crucial factor deciding the fate of the patient. This “quantitative and time‐/sequence‐dependent” model has several implications for prevention, diagnosis, and therapy of COVID‐19 at all ages.
Background: Magnesium sulfate (MgSO
4
) is considered to be a well-tolerated, inexpensive, and effective medication for severe asthma exacerbations. We surveyed physicians who treat patients with ...asthma to evaluate the current knowledge and usage of MgSO
4
. Methods: A self-administered questionnaire was e-mailed to members of the Turkish National Society of Allergy and Clinical Immunology and was distributed to participants of its annual congress. Results: Of the 456 respondents (mean age: 36.53 ± 9.11 years), 42.3% reported to use MgSO
4
in asthma exacerbations in their practice, and 48.7% agreed that MgSO
4
was included in asthma guidelines. The best known indication was that it was useful only in patients refractory to bronchodilators and systemic corticosteroids (67.7%). The two most common reasons to use MgSO
4
were to shorten hospital stay (94.7%), and prevent admission to intensive care unit (80.3%). The respondents mostly used MgSO
4
in the treatment of severe or life-threatening exacerbations. Thirty-nine percent believed that MgSO
4
had no effect on discharge period, and 29% of them marked minor side effects. The most common reason for not using MgSO
4
was inexperience (36.5%). Having an academic affiliation (OR = 3.20, p < 0.001), the number of asthmatic outpatients seen per month (OR = 1.82, p = 0.007), and more recent graduation from medical school (≤1991) (OR = 0.23, p < 0.001) were associated with the use of MgSO
4
in the multivariate analysis. Conclusion: Even though the effect of MgSO
4
in acute severe asthma is well known, only half of the physicians dealing with asthma patients have used it in their practice. Education and encouragement in this regard are necessary.
Abstract Aim To evaluate the pepsin and oxidative stress markers in exhaled breath condensate (EBC) in patients with gastroesophageal reflux disease (GERD). Patients and Method Patients with a ...presumptive diagnosis of GERD with recurrent respiratory and gastrointestinal problems aged between 2 and 14 years were included in the study. All patients underwent pH monitoring. Patients with a reflux index (RI) ≥ 4 were assessed as the reflux group, and those with an RO < 4 were assessed as the non-reflux group. Pepsin levels and oxidative stress markers NO metabolites (NOX) and total sulphydrile (TSH) levels were measured in the EBC. Results There were 24 patients in the reflux group RI 17.6 (6.6–46.4) median, interquartile range and 23 in the non-reflux group RI 0.8 (0.5–1.9) (p < 0.001). Pepsin levels in the EBC were below the level of detection. The median levels of NOx in the EBC of children with reflux 13.7 μmol/L (7.3–24.5) were lower in than non-reflux group 21.0 μmol/L (14.0–25.2) (p = 0.034). There was a negative correlation between reflux index and NOX levels in EBC (rs: − 0.331, p = 0.023). In contrast, there was no difference in TSH levels between the reflux and non-reflux groups 37.4 μmol/L (30.2–44.6) vs 40.1 μmol/L (37.4–44.9), respectively, (p > 0.05). Conclusion Decreased levels of NOX in patients with GER disease suggest increased oxidative stress in airways of these patients.
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