Geographic distribution and phenotype of European people with cystic fibrosis carrying A1006E mutation

BACKGROUND

A1006E is a Cystic Fibrosis (CF) mutation that is still not widely known. We report phenotypic features and geographic distribution of the largest cohort of people with CF (pwCF) carrying A1006E to date.

METHODS

Study of European pwCF carrying A1006E mutation, included in the European CF Society Patient Registry (ECFSPR). Genotype, ancestries and all variables recorded were compared to a cohort of F508del/F508del patients. Rate of decline in percentage-of-predicted FEV₁ (ppFEV₁) was also analyzed using the 2010-2017 ECFSPR.

RESULTS

44 pwCF carrying A1006E were reported (59% males), median age 33 years old (3-58), 54.5% Spanish and 40.9% Italian, most with ancestry in Murcia (Spain) and Lazio (Italy) regions. Compared to F508del homozygous, A1006E-pwCF were significantly older (75% vs. 52.5% ≥ 18 years old) and diagnosed at later median age (6.98 vs. 0.29 years); showed lower rates of meconium ileus (2.33% vs. 17.7%), pancreatic insufficiency (27.91% vs. 99.26%), diabetes (2.33% vs. 21.98%), liver disease (6.98% vs. 36.72%) and Pseudomonas aeruginosa chronic colonization (30.95% vs. 42.51%); and presented better nutrition (BMI z-score 0.44 vs. -0.43) and ppFEV₁ (90.8% vs. 78.6%), with 18.9% (most >40 years old) having a ppFEV₁<70%. Additional ppFEV₁ decline (0.96% per year) was attributed to F508del/F508del genotype (p = 0.0007). None died or needed organ transplantation during the study period.

CONCLUSIONS

A1006E-pwCF are mainly of Western Mediterranean Spanish and Italian descent. When compared with F508del/F508del-pwCF, they usually have a milder form of the disease, associated with pancreatic sufficiency and slower FEV₁ decline. However, some will develop progressive respiratory impairment during adulthood.

Impact of SARS-CoV-2 infection in patients with cystic fibrosis in Spain: Incidence and results of the national CF-COVID19-Spain survey

BACKGROUND

Given the high incidence of confirmed infection by SARS-CoV-2 and mortality by COVID-19 in the Spanish population, its impact was analysed among persons with Cystic Fibrosis (CF) as a group at risk of a worse evolution. The possible causes of the incidence observed in them are explained and how CF Units have faced this health challenge is detailed.

METHODS

Retrospective descriptive observational study, for which a Spanish CF Patients with Confirmed COVID-19 Registry is created, requesting information on number of people affected between 8 March-16 May 2020 and their clinical-demographic characteristics from the CF Units participating in the European Cystic Fibrosis Society Patient Registry (ECFSPR). The accumulated incidence is calculated, compared with that of the general population. Additionally, a survey (CF-COVID19-Spain) is carried out on prevention of SARS-CoV-2 infection, workings of CF Units and possible reasons for the incidence observed.

RESULTS

COVID-19 was diagnosed in eight CF patients, one of whom had received a lung transplant. The accumulated incidence was 32/10000 in CF patients and 49/10000 in the general population. General death rate was 5.85/10000 while no CF patients included in the ECFSPR died. The characteristics of those affected and the results of the survey are described.

CONCLUSIONS

Despite being considered a disease at high risk of severe COVID-19, the low incidence and mortality in CF patients in Spain contrasts with the figures for the general population. The possible factors that would explain such findings are discussed, with the help of the results of the CF-COVID19-Spain survey.