CFTR-Related Disorder in a Patient with Sj？gren-Associated Bronchiolitis and Recurrent Pulmonary Infections: A Diagnostic Challenge

Cystic fibrosis (CF) is an autosomal recessive disorder caused by an inherited defect in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. It classically manifests with chronic sinopulmonary disease, pancreatic insufficiency, and infertility/subfertility. However, there are many patients whose symptoms do not align well with classic CF presentations, leading to a separate classification of many CFTR-related disorders which may have variable genotypic and phenotypic expression. This is the case of a 42-year-old female with recurrent sinopulmonary infections, autoimmune disorders, asthma, and progressive respiratory failure who had been admitted to the hospital multiple times over the course of months. Ultimately, an intermediate sweat chloride test led to further investigation which resulted in a diagnosis of a CFTR-related disorder caused by an F508del mutation. This diagnosis led to the initiation of CFTR modulator therapy, which was incorporated into a broader multidisciplinary treatment strategy that also included antimicrobial therapy, immunosuppression for Sj？gren-associated bronchiolitis, and airway-clearance measures. Although the patient experienced transient clinical stabilization, the relative contribution of each intervention could not be determined, and the patient was ultimately referred for bilateral lung transplant.