Cystic Fibrosis

Cystic Fibrosis (CF) is an autosomal recessive genetically inherited disorder that affects secretory cells producing mucus, sweat, and digestive enzymes. Specifically, the cystic fibrosis transmembrane conductance regulator (CFTR) gene is mutated in CF patients, resulting in thick secretions that can block airways and ducts, which proves fatal over time. This video focuses on the physiological basis for how the thick mucus secretions affect the lungs’ ability to function optimally.

Self-Assessment Questions:

Click here to test your understanding of Cystic Fibrosis.

Discussion Questions:

1. Based on the physiological causes for CF as explained in the video, is CF better classified as a restrictive or obstructive lung disease and why? What characteristics of the disease helped you come to your conclusion?
2. CF patients’ well being and health are often measured through FEV1 tests. What do these tests measure, and why is this data useful in determining patient health? What are the upsides and downsides of using this as the primary indication of condition in CF patients? Use this analysis of the FEV1 metric in CF patients by Szczesniak et al. to help you answer this question.
3. FEV1 is not the only lung function measurement that can indicate changes in CF patient lung function. What are two other lung volume values or tests that can be done to effectively evaluate lung function in CF patients and why? What would be the physiological cause of changes in these values in CF patients? Use this article by Delgado et al. to help in identifying lung volumes and tests.
4. Based on what you have learned about how CF affects normal physiological function and this resource by Sawicki et al. that examines treatment strategies, name at least three treatment strategies for CF and explain why each is effective in relieving CF symptoms.
5. What consequences may the reduced airflow seen in CF patients have for cardiac function? What parts of heart function are more likely to be normal? Use this study by Fraser et al. to help identify areas of abnormality in cardiovascular function for CF patients.
6. What other physiological problems do you think are common in CF patients based on the physiological causes discussed in the video? Try to find literature on these functions with people in CF that back your claims, and give reasoning as to why these functions would be affected.

Continue Reading:

• R. Szczesniak, S. L. Heltshe, S. Stanojevic, and N. Mayer-Hamblett, “Use of FEV1 in cystic fibrosis epidemiologic studies and clinical trials: A statistical perspective for the clinical researcher,” J. Cyst. Fibros., vol. 16, no. 3, pp. 318–326, 2017. Read this resource here.
  • This analysis of FEV1 use in cystic fibrosis patients explains how this metric is used to assess lung function. The article goes on to assess the accuracy of this measurement in CF patient survival predictions and examines the advantages and disadvantages of this metric’s use.
• B. J. Delgado and T. Bajaj, “Physiology, lung capacity,” in StatPearls [Internet], StatPearls Publishing, 2021. Read this resource here.
  • This article explains different methods used to measure lung volumes as well as how different volumes and tests can be used to diagnose different pulmonary pathologies.
• G. S. Sawicki, D. E. Sellers, and W. M. Robinson, “High treatment burden in adults with cystic fibrosis: challenges to disease self-management,” J. Cyst. Fibros., vol. 8, no. 2, pp. 91–96, 2009. Read this resource here.
  • This study examines the treatment routines of adults with CF and reports the efficacy of different treatments as well as the infection types common in CF patients. The reasoning behind different treatments and what symptoms or infections they aim to relieve is also addressed.
• K. L. Fraser, D. E. Tullis, Z. Sasson, R. H. Hyland, K. S. Thornley, and P. J. Hanly, “Pulmonary hypertension and cardiac function in adult cystic fibrosis: role of hypoxemia,” Chest, vol. 115, no. 5, pp. 1321–1328, 1999. Read this resource here.
  • This study uses sleep studies in CF patients and combines lung function and cardiac function measurements to determine the ways in which reduced lung function in CF patients affects cardiac function.

About the Creator:

This video was created by a student in the Rice Bioengineering Class of 2024 (used with permission).