Histamine [G-BSA]

Objective Asthma and bronchiectasis are known to be two distinct diseases with different etiology, pathophysiology, management, and prognosis. However, a high prevalence of bronchiectasis has been reported in patients with severe asthma. Thus, it is of great importance to identify the impact of bronchiectasis on asthmatic patients. Data sources:Databases including PubMed, Embase, Cochrane, Web of Science were searched comprehensively to identify relevant human clinical studies published until February 2020. Study selections:Two investigators (Gelei Lan and Guochao Shi) independently obtained the potentially eligible articles based on their titles and abstracts. When opinions differed between the investigators, discussions were made to reach an agreement. The authors of the included studies were contacted for inquiry when necessary. Results Six observational studies with 1004 patients were included in the meta-analysis. The mean prevalence of bronchiectasis in patients with asthma was 35.2% (ranging from 2.2% to 47%). Asthmatic patients with bronchiectasis were older, had a longer disease duration, exhibited greater severity, and showed more frequent exacerbations and hospitalization, and poorer lung function, compared with the patients without bronchiectasis. Conclusion Despite of the heterogeneity between included studies and detectable publication bias, this meta-analysis demonstrated the impact of comorbid bronchiectasis on asthmatic patients. Thus, coexistence of bronchiectasis should be considered a clinical phenotype of asthma, which may have associations with exacerbation and hospitalization.

Coronavirus Disease 2019 (COVID-19) caused 2 million cases and more than 150,000 deaths worldwide as of mid-April 2020.1 Clinical trials are under way to assess the efficacy of a variety of antiviral drugs; however, many of these drugs have toxicities and thus far no drug has been proven to improve outcomes in patients with COVID-19. Famotidine is a histamine-2 receptor antagonist that suppresses gastric acid production. In vitro, famotidine inhibits human immunodeficiency virus replication.2 Recently, Wu et al.3 used computational methods to predict structures of proteins encoded by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genome and identified famotidine as one of the drugs most likely to inhibit the 3chymotrypsin-like protease (3CLpro), which processes proteins essential for viral replication.4 We hypothesized that famotidine would be associated with improved clinical outcomes among hospitalized patients with COVID-19. To explore this, we performed a retrospective cohort study at a single academic center located at the epicenter of the COVID-19 pandemic in the United States.