Cystic Fibrosis: Early Diagnosis, Sweat Test, and Differentiation of Bronchiectasis Causes

Cystic fibrosis (CF) is a multisystem disease primarily affecting the epithelial tissues of the respiratory tract, exocrine pancreas, intestines, hepatobiliary system, and exocrine sweat glands. Pulmonary disease is the leading cause of morbidity and mortality in CF, characterized by bronchiectasis and progressive obstructive lung disease. Early diagnosis is crucial for improving the prognosis and quality of life for patients. However, differentiating CF from other causes of bronchiectasis can pose a significant clinical challenge.
Diving Deeper into Diagnosis and Differentiation
The diagnosis of cystic fibrosis is established through a combination of newborn screening with elevated levels of immunoreactive trypsinogen, suggestive clinical symptoms or family history, and evidence of an abnormality in the cystic fibrosis transmembrane conductance regulator (CFTR) function. This includes a positive result on the sweat test with chloride levels ≥60 mmol/L, biallelic pathogenic variants of CFTR, or measurement of nasal transepithelial potential difference consistent with CF [1].
Genetic evaluation is essential for confirming the diagnosis and differentiating CF from other conditions that can also cause bronchiectasis, such as primary ciliary dyskinesia (PCD) and non-CF bronchiectasis. PCD, for instance, is a multisystem disease that is also associated with bronchiectasis due to dysfunction of motile cilia, leading to recurrent respiratory tract infections [2].
Additionally, conditions such as allergic bronchopulmonary aspergillosis (ABPA) can complicate the differential diagnosis. ABPA occurs in patients with asthma or CF and results in pulmonary infiltrates and irreversible bronchiectasis [3].
Conclusions
Early diagnosis of cystic fibrosis and differentiation from other causes of bronchiectasis are essential for the appropriate management of these conditions. The combination of clinical, genetic, and imaging tests is crucial for establishing an accurate diagnosis. Early identification and appropriate treatment can significantly improve the prognosis and quality of life for affected patients. Ongoing research and medical education are fundamental to enhancing the detection and management of these complex respiratory diseases.
Referencias
- [1] Cystic Fibrosis
- [2] Primary ciliary dyskinesia: overlooked and undertreated in children
- [3] Allergic bronchopulmonary aspergillosis
Created 13/1/2025