Mean delay between symptoms onset and realization of the blood test was 44.1 days ( 17.4 days C standard deviation). 4.?Discussion These data suggest that SARS-CoV-2 seroprevalence among CF patients is low (2.7%) and even lower than in the Belgian population in the same period (4.3%) [9]. (SARS-CoV-2). The main risk factors associated with a worse outcome include age and comorbidities such as hypertension, diabetes mellitus or chronic lung disease [1]. Cystic fibrosis (CF) is usually a multisystemic disorder, responsible for a chronic lung disease. Obstruction of the airways by viscous secretions and the consecutive inflammation induce progressive destruction of the lungs. Several comorbidities are described in CF, including diabetes mellitus and liver disease [2]. Information is usually lacking around the prevalence and on the clinical impact of COVID-19 among CF patients. In a multinational report, 40 cases have been reported in 8 countries. In contrary with the H1N1 influenza pandemic in 2009C2010 where a significant morbidity was described among affected CF patients [3], the outcomes of COVID-19 in this population seem to be less severe than Acetyl-Calpastatin (184-210) (human) expected [4]. To our knowledge, no EMCN data Acetyl-Calpastatin (184-210) (human) are available regarding the SARS-CoV-2 seroprevalence among CF patients. In this monocentric prospective study, we report SARS-CoV-2 seroprevalence of 149 CF patients. 2.?Methods 2.1. Study population CF patients followed in the CF reference center of the Cliniques universitaires Saint-Luc (Brussels), were recruited prospectively by receiving a letter made up of an empty tube to test IgM and IgG against SARS-CoV-2. Between April 16, 2020 and May 19, 2020, sera were collected from 149 patients (first case in Belgium on February 4, 2020, peak of the epidemy on April 10, 2020, lockdown for CF patients since March 12, 2020). Blood sampling was performed either in the CF center or in another local center and brought the same day to the CF center through a drive-in system. Patients were contacted by phone to collect the presence and timing of symptoms. All patients respond to the classical definition of CF, defined by Farrell [5]. Clinical data are presented in the Table?1 . The local ethical committee stated that no informed consent was needed as the Helsinki declaration was respected, as it was considered as a regular monitoring in this sanitary crisis. Table 1 Patient characteristics of the study population.
Subjects, n149Sex (F/M)73/76Smoking history (never/former/current)0/0/5F508del/F508del (n/%)63/42.3Pancreatic sufficiency (n/%)26/17.4Age, yrs24.9??15Children/Adults52/97BMI, Z-score?0.39??2.24FEV1,% predicted (n?=?134)85??25.9FVC,% predicted (n?=?134)95.8??19.1 Open in a separate window Demographic data, genotype, lung function assessments, smoking history are stated for the patients. N is usually specified when data are missing. Data are means standard deviation. Definition of abbreviations: F, female; M, male; yrs, years; BMI, body mass index; FEV1, forced expiratory volume in one second; FVC, forced vital capacity. 2.2. Anti-SARS-CoV-2 IgM and IgG detection Measurements of specific anti-SARS-CoV-2 IgM and IgG antibodies were performed with the Maglumi 2019-nCoV IgG and IgM fully automated quantitative chemiluminescent immunoassays (CLIA). This binding antibody technic detects antibodies against proteins N, S1 and S2 of SARS-CoV-2. Samples were processed according to the manufacturer’s instructions around the Maglumi 800 analyzer (Snibe Diagnostic, Shenzhen, China) [6]. These automated immunoassays use magnetic microbeads coated with SARS-CoV-2 recombinant antigens labeled with ABEI, a non-enzyme small molecule with a special molecular formula that enhances stability in acid and alkaline solutions. The threshold of positivity for both IgM and IgG assays is usually 1.0 arbitrary unit (AU)/mL. The sensitivity and specificity were previously addressed as well as the comparison with Acetyl-Calpastatin (184-210) (human) anti-SARS-CoV-2 IgA and IgG enzyme-linked.