Important Effects of Human Rhinovirus C Infection and Acute Exacerbations of Asthma in Children

Important Effects of Human Rhinovirus C Infection and Acute Exacerbations of Asthma in Children

呼吸道病毒性感染，特別是人類鼻病毒（HRV）感染，在氣喘兒童氣喘急性發作中扮演重要角色。我們研究了台灣兒童氣喘急性發作與HRV-A，-B和-C亞型（species）及基因型（genotype）感染之間的相關性。我們收集2015年10月至2017年3月間，178名小於15歲的氣喘兒童個案，包括急性發作及非急性發作各89例，並連續定期採集呼吸道檢體做研究。實驗採用即時熒光定量PCR技術，以HRV 5'UTR基因為模板來檢測HRV病毒濃度；又採用巢式PCR和基因定序來鑑定其亞型及基因型。在178例氣喘兒童第一次就診之HRV陽性率就高達42.7%（76/178），以HRV-C及HRV-A亞型為主；其中急性氣喘及非急性氣喘發作之HRV陽性率各為57.3%（51/89）及28.1%（25/89）；在急性氣喘發作兒童有顯著HRV高感染率，且HRV-C最為相關（p=0.000002）。此外，高濃度鼻病毒也易導致氣喘急性發作（p＜0.05）。在178例氣喘兒童共410件呼吸道檢體中，166件為病毒感染，主要仍為HRV（76.5%）；重要的發現為，發生多次病毒感染且均為HRV的23（23/40,57.5%）個案例中，其病毒基因型均不相同，故這些氣喘兒童個案是重複而非持續感染造成。

Viral respiratory tract infections, particularly by human rhinoviruses (HRV), play an important role in acute exacerbations of asthma in asthmatic children. We examined the correlation between acute exacerbations of asthma in Taiwanese children and infection with HRV-A, -B, and -C species and genotypes. We enrolled 178 asthmatic patients aged ＜15 years from October 2015 to March 2017, including each 89 cases of acute exacerbations and non-acute exacerbations of asthma and carried out continuous and regular collection of respiratory tract samples for study. Real-time PCR was used to measure HRV virus concentrations with HRV 5'UTR gene, nested PCR and sequencing were employed to identify the species and genotype. Among the 178 asthmatic children, the HRV positive rate in the first consultation was 42.7%, mainly comprising HRV-C and HRV-A species. The HRV positive rate was 57.3% and 28.1% among patients with acute and non-acute exacerbations of asthma, respectively. Children with acute exacerbations of asthma have significantly high HRV infection rates, especially HRV-C (p=0.000002). In addition, high concentrations of HRV can increase susceptibility to acute exacerbations of asthma (p＜0.05). A total of 410 respiratory tract samples were collected from 178 asthmatic children and 166 samples were positive for viral infection, mainly HRV (76.5%). Among 23 (57.5%) patients with multiple HRV infections, the viral genotypes were all different. Therefore, these asthmatic children suffered from repeated and non-persistent infections. Acute exacerbations of asthma were associated with HRV-C genotypes, high concentrations of HRV and repeated infections with different HRV genotypes, thus providing important data and a new direction for rhinovirus epidemiology in Taiwan.