Severe COVID-19 in Hospitalized Carriers of Single CFTR Pathogenic Variants

Abstract

The clinical presentation of COVID-19 is extremely heterogeneous, ranging from asymptomatic to severely ill patients. Thus, host genetic factors may be involved in determining disease presentation and progression. Given that carriers of single cystic fibrosis (CF)-causing variants of the CFTR gene-CF-carriers-are more susceptible to respiratory tract infections, our aim was to determine their likelihood of undergoing severe COVID-19. We implemented a cohort study of 874 individuals diagnosed with COVID-19, during the first pandemic wave in Italy. Whole exome sequencing was performed and validated CF-causing variants were identified. Forty subjects (16 females and 24 males) were found to be CF-carriers. Among mechanically ventilated patients, CF-carriers were more represented (8.7%) and they were significantly (p < 0.05) younger (mean age 51 years) compared to noncarriers (mean age 61.42 years). Furthermore, in the whole cohort, the age of male CF-carriers was lower, compared to noncarriers (p < 0.05). CF-carriers had a relative risk of presenting an abnormal inflammatory response (CRP ≥ 20 mg/dL) of 1.69 (p < 0.05) and their hazard ratio of death at day 14 was 3.10 (p < 0.05) in a multivariate regression model, adjusted for age, sex and comorbidities. In conclusion, CF-carriers are more susceptible to the severe form of COVID-19, showing also higher risk of 14-day death.

Keywords: CF carrier screening; CFTR; COVID-19; host genetics.

Figure 1

Survival Study: Kaplan–Meier 14-day survival study comparing carriers of single CF-causing variants (red) and noncarriers (black). Log-rank test p = 0.0392; Univariable Cox analysis (UA) HR = 2.86; 95% CI 1.01–8.15; p = 0.0485. Multivariable Cox analysis (MA) with adjustment for confounding variables HR = 3.10; 95% CI, 1.09–8.85; p = 0.0346.