SARS-CoV-2 and Cystic Fibrosis: Expectations Versus Reality, a Literature Review

Abstract

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for the COVID-19 pandemic, is expected to cause severe illness in people with cystic fibrosis (CF). The infection prevalence and clinical outcomes of this patient cohort to SARS-CoV-2 were explored, alongside contributing factors to the observed response. Search terms were entered into Medline/PubMed and Embase databases, with relevant published papers written in English chosen. The COVID-19 trajectory in people with CF (including children) was similar to the general population. Specifically, in Veneto, Italy, the infection rate of people with CF was nearly half compared to the general population (0.19% versus 0.40%, respectively). Similarly, in Spain, the cumulative incidence of COVID-19 was lower compared to the general population: 32/10,000 and 49/10,000 respectively. Likewise, in Belgium 2.7% of patients with CF had SARS-CoV-2 antibodies compared with 4.3% of the general population. Moreover, in Europe, fewer CF–COVID-19 cases and deaths were reported compared to the general population (1.1%, 0.9%; and 3.2%, 2.3%, respectively). Overall, worse outcomes in CF were associated with poorer lung function and post-transplant status. The encouraging response of people with CF to COVID-19 is hypothesised as due to higher levels of anti-inflammatory angiotensin-1-7 and lower levels of pro-inflammatory IL-6 and protease transmembrane serine protease-2, utilised by SARS-CoV-2 to penetrate cells. Additionally, the use of CF medication, chiefly Dornase alfa and CF transmembrane conductance regulator modulators as well as CF cohort characteristics, predominantly younger age, and early isolation might have mitigated COVID-19 severity. Thus, people with CF do not appear to have a higher COVID-19 infection prevalence or worse clinical outcomes compared to the general population.