Prevalence of Respiratory Viral Infections in Korean Adult Asthmatics With Acute Exacerbations: Comparison With Those With Stable State

Abstract

PurposeViral infections are involved in ~50% of exacerbations among Caucasian adult asthmatics. However, there have been few reports on the causative virus of exacerbations in Korean adult asthmatics. Thus, we compared frequencies and types of viruses between lower respiratory tract illnesses (LRTIs) with exacerbations (exacerbated LRTIs) and those without exacerbations (stable LRTIs) to evaluate contribution of respiratory viruses to exacerbations.MethodsViral RNA was extracted from sputum using the Viral Gene-spin™ Kit. Reverse transcription-polymerase chain reaction (RT-PCR) was performed to detect adenovirus (ADV), metapneumovirus (MPV), parainfluenza virus (PIV) 1/2/3, influenza virus (IFV) A, IFV B, respiratory syncytial virus (RSV) A/B, and rhinovirus (RV) A.ResultsAmong the 259 patients, 210 underwent a single sputum examination, and the remaining 49 underwent 2 to 4 sputum examinations. Virus was detected in 68 of the 259 exacerbated episodes and in 11 of the 64 stable episodes. Among the exacerbated episodes, RV was the most frequently detected virus, followed by influenza A, parainfluenza, RSV A/B, and ADV. Among the 11 stable episodes, RV was most frequently detected. Detection rates of these viruses did not differ between the 2 groups (P>0.05). Thirty-five patients underwent the virus examination at 2 episodes of exacerbation, while 14 patients underwent at each time of exacerbated and stable episodes. Virus detection rate at the second examination was significantly higher in cases with 2 exacerbation episodes than in those with initial exacerbation and sequential stable episodes (P=0.003). A seasonal pattern was noted in the detection rates of RV (September to December), IFV (January to April), PIV (May to September), and RSV A/B (September to April).ConclusionsRespiratory viruses were identified in approximately 20% of LRTI irrespective of the presence of asthma exacerbation. RV and IFV A/B were most frequently detected. A group of patients experienced frequent viral infections followed by asthma exacerbations.

Prevalence and clinical symptoms of Human Parainfluenza and Influenza infections in patients admitted to Mazandaran province health centers, 2019

“…For instance, the prevalence rates of parainfluenza and influenza viruses in Brazil were 30% and 21%, respectively [26]. Moreover, in a study conducted in Korea between 2 groups of patients with severe and stable con-ditions, the parainfluenza virus was the most common virus (16.8%) detected [27].…”

Lower Airway Virology in Health and Disease—From Invaders to Symbionts

“…A study conducted by Ki-Hyun Seo et al detected RV in 45.5% of the LRTs of asymptomatic stable asthma patients. Moreover, those infected with rhinovirus are more likely to have more severe LRT infections, with longer-lasting symptoms [ 46 ]. Few studies have shown that RV induces expression of major epithelial mucin MUC5AC, leading to mucus hypersecretion.…”

“…Thus, IFN deficiency results in more severe and prolonged respiratory symptoms in asthmatic patients. The influenza virus is another common virus in asthmatic patients [ 46 ]. During the influenza virus pandemics in 2009, asthma was one of the risk factors associated with increased hospitalization among children and adults.…”

Osteopontin contributes to late-onset asthma phenotypes in adult asthma patients

“…In subjects with LOA, airway remodeling can be either pathological or physiological due to aging-related structural changes in the airway 2,8 . Additionally, viral respiratory infections can worsen airway remodeling in adult asthma 9 . Respiratory viral infections induce the release of proinflammatory cytokines such as interleukin (IL)-6 and IL-8 from human airway epithelial cells (HAECs) and initiate cell recruitment, which amplifies airway inflammation and subsequent airway remodeling, such as long-term alterations in airway structures and functions in asthma 10,11 .…”