Ayşen BİNGÖL, Deniz ACICAN, Özgül ALPER, Ayşen BAŞARAN, Abdurrahman Erdem BAŞARAN, Dilara Fatma KOCACIK UYGUN

Initial regional evaluation of the Cystic Fibrosis Newborn Screening Program: data from the Mediterranean coast of Turkey

Background/ aim: Since January 2015, the Cystic Fibrosis Newborn Screening (CFNS) program has been implemented in Turkey. Weaimed to evaluate the demographic, clinical, and laboratory data of cases referred from the CFNS program and to determine the mostsuitable cut-off value for immunoreactive trypsinogen (IRT)-1 and immunoreactive trypsinogen (IRT-2) that are used in the CFNSprogram in Turkey.Materials and methods: A total of 156 Turkish Caucasian subjects were determined as positive cases during 3 years, from January 2015to January 2018, and were referred to the pediatric pulmonology clinics of Akdeniz University Hospital, Antalya, Turkey, for the nationalCFNS program. The evaluation was made considering the IRT-1 and IRT-2 values, demographic characteristics, sweat test results, CFTRgenotypes, and diagnoses.Results: Nine patients were diagnosed with cystic fibrosis (CF). Eight were diagnosed with CF-related metabolic syndromes and threewere determined to be CF carriers. The ratio of CF to CF-related metabolic syndrome was determined as 1.1:1. Considering the limitsof the present CFNS program and the IRT method, the positive predictive value (PPV) for the referred cases was determined as 5.8%.When a cut-off value of 105.6 ng/mL was taken for IRT-1, sensitivity was 100%, specificity was 59%, and PPV was 12.8%. For a cut-offvalue of 88.75 ng/mL for IRT-2, sensitivity was determined as 90%, specificity as 65%, and PPV as 15.2%.Conclusion: This is the first detailed clinical study to evaluate the data from the CFNS program along the Mediterranean coast ofTurkey. As false positive results are extremely high in Turkey, there is an urgent need for revision of the IRT-1 and IRT-2 limits byevaluating the data of the whole country.

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