Cystic Fibrosis

There is still no cure for this disease, but supportive therapies have improved markedly in the last twenty years. The recurrent lung infections are now much better controlled with powerful, new-generation antibiotics, though, unfortunately, many patients eventually develop infections with drug-resistant bacteria. A variety of approaches are used to break up and remove the thick mucus secretions in the lung, including mucolytic (mucusbreaking) agents, bronchodilators, and chest physical therapy. One type of mucolytic treatment is DNase, a DNA-destroying enzyme that breaks up the long, sticky DNA strands left by dying cells. Some patients with end-stage lung disease can be rescued by lung transplantation. Patients with pancreatic obstruction can be managed with pancreatic enzyme supplements, and affected men with vas deferens obstruction have been able to father children by a technique called sperm aspiration, followed by in vitro fertilization.

The ultimate hope for the cure of CF lies in gene replacement therapy. A number of clinical trials are under way, most attempting to deliver the normal CF gene to the bronchial epithelium by aerosol spray, using a viral vector (usually adenovirus, a common respiratory virus that naturally targets the desired tissue). Thus far the attempts have not been completely successful, as most patients develop an immune response against the virus during the course of therapy. But with the median life expectancy of CF patients now at thirty years just through conventional therapies, the hope is that many CF patients alive today will survive long enough to avail themselves of gene therapy once it is perfected.