Coronavirus disease 2019 (COVID-19) is a global pandemic infectious disease caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), and abnormal, overactivated innate immunity and "cytokine storms" have been proposed as potential pathological mechanisms for rapid COVID-19 progression. Theoretically, asthmatic patients should have increased susceptibility and severity for SARS-CoV-2 infection due to a deficient antiviral immune response and the tendency for exacerbation elicited by common respiratory viruses. However, existing studies have not shown an expected prevalence of asthmatic individuals among COVID-19 patients. Certain aspects of type 2 immune response, including type 2 cytokines (IL-4, IL-13, etc.) and accumulation of eosinophils, might provide potential protective effects against COVID-19. Furthermore, conventional therapeutics for asthma, including inhaled corticosteroids, allergen immunotherapy (AIT), and anti-IgE monoclonal antibody, might also reduce the risks of asthmatics suffering infection of the virus through alleviating inflammation or enhancing antiviral defense. The interactions between COVID-19 and asthma deserve further attention and clarification.

Background The impact of asthma on COVID-19 remains largely unknown. Objective To investigate the asthma prevalence among COVID-19 patients and compare outcomes between asthma and non-asthma patients. Methods In this systematic review and meta-analysis, we searched PubMed, Embase, Web of Science, Biorxiv and Medrxiv for studies reporting asthma prevalence in general COVID-19 patients or comparing outcomes between asthma and non-asthma patients, and excluded duplicate publications, reviews, editorials, comments, single case reports or small case series (<10 cases). We determined the pooled estimates of effect using random-effect-model. Results Based on 131 studies (410382 patients), we found great variability in the prevalence of comorbid asthma among COVID-19 patients in different countries or regions ranging from 1.1% to 16.9%. No significant difference in asthma prevalence was found between hospitalized and non-hospitalized (RR: 1.15, 95% confidence interval: 0.92-1.43), severe and non-severe (RR: 1.21, 95% confidence interval: 0.92-1.57), ICU and non-ICU (RR: 1.19, 95% confidence interval: 0.92-1.54,), dead and survived (RR: 0.90, 95% confidence interval: 0.73-1.11), intubated/mechanically ventilated and non-intubated/mechanically ventilated (RR: 0.91, 95% confidence interval: 0.71-1.17) COVID-19 patients. Asthmatic patients have a lower risk of death compared with non-asthmatic patients (RR: 0.65, 95% confidence interval: 0.43-0.98). Asthma is not associated with higher risk of intubation or mechanical ventilation (RR: 1.03, 95% confidence interval: 0.72-1.46). Conclusions There is great variability in asthma prevalence among COVID-19 patients in different countries or regions. Asthma is not associated with higher COVID-19 severity or worse prognosis, and asthmatic patients are found to have lower risk of death compared with non-asthmatic patients.

INTRODUCTION: The prognosis of Cronkhite–Canada syndrome (CCS) is considered poor. Despite the recent therapeutic improvements, the survival outcomes and prognostic factors have been less studied. This study aimed to investigate the long-term clinical and endoscopic outcomes of CCS. METHODS: Thirty-one patients diagnosed since 1999 and followed up for over 6 months were included. Data regarding survival outcomes, clinical symptoms, endoscopic findings, and treatment were collected and analyzed. R (version 3.6.1) was used to perform the survival analyses. RESULTS: The median (interquartile range) follow-up time was 42.5 (19.5–85.8) months. The 5-year overall survival (OS) was 87.4%. The maximum gastric polyp size over 2 cm was associated with worse OS (Hazard ratio [HR]: 18, 95% confidence interval [CI]: 1.6–210, P = 0.021). The 3-year relapse-free survival (RFS) after corticosteroid treatment was 66.8%. Age older than 60 years (HR: 7.0, 95% CI: 1.5–33.0, P = 0.015) and maximum gastric polyp size over 2 cm (HR: 6.0, 95% CI: 1.6–23.0, P = 0.009) were associated with worse RFS. Twenty-three patients received follow-up endoscopic examinations, with a median (interquartile range) follow-up time of 29.0 (14.0–53.5) months. Eight (34.8%) and 12 (52.2%) patients achieved complete remission under gastroscopy and colonoscopy, respectively. Colonic lesions showed a tendency of earlier responses compared with gastric lesions (25.0 [11.3–39.8] months vs 31.0 [21.0–39.8] months). DISCUSSION: Patients with CCS usually responded well to glucocorticoids with a fairly good 5-year survival rate. Large gastric polyp was associated with worse OS and RFS, whereas age older than 60 years was another predictor for worse RFS. Diffuse gastrointestinal lesions partly or completely resolved after treatment, and colonic lesions showed a better response than gastric lesions.