CF And Effects of Drugs Mixed Ex Vivo With Sputum for Mucolytic Treatment

Pseudomonas lung infection is a major cause of morbidity and mortality occurring in multiple
clinical settings. Patients with cystic fibrosis have lung colonization with Pseudomonas from
an early age, and overwhelming pseudomonal lung infection is the most common cause of death
in these patients. In addition, Pseudomonas pneumonia is common in immunocompromised patients
and in patients intubated for management of respiratory failure. Particularly worrisome is
the increasing frequency of P. aeruginosa isolates that are resistant to all or most
currently available antibiotics. The mechanism of virulence of P. aeruginosa includes soluble
lectins that recognize host oligosaccharides on mucins and the cell glycocalyx. P. aeruginosa
has two soluble lectins - LecA, also known as PA-IL and LecB, also known as PA-IIL. PA-IL
binds galactose and PA-IIL binds fucose. Notably, PA-IIL binds the fucose containing Lewis a
oligosaccharide with very high affinity and the role of PA-IIL in biofilm formation is shown
by the absence of biofilm formation in Pseudomonas mutants lacking PA-IIL and by the efficacy
of multivalent fucosyl-peptide dendrimers in preventing and disrupting Pseudomonas biofilm
formation. D-galactose and L-fucose have been successfully used to treat P. aeruginosa
infection in a case report, which hints at the potential for glycomimetic therapy in CF.
These monosaccharides are weak inhibitors of PA-IIL, however, and multivalent glycomimetics
will be needed for more effective inhibition.

Aspergillus fumigatusinfection is responsible for the majority of human and animal
aspergillosis disease, even though air sampling studies show that its conidia usually
comprise only a small percentage of total airborne fungal challenge. It is both a primary and
opportunistic pathogen, and it is particularly troublesome for patients with cystic fibrosis.
It causes multiple lung diseases, includingchronic pulmonary aspergillosis, allergic
bronchopulmonary aspergillosis, and invasive pulmonary aspergillosis. Aspergillomas also
occur in patients with cavitary lung diseases. Together, these diseases cause significant
morbidity and mortality, and available treatments are suboptimal. Most patients with chronic
pulmonary aspergillosis require antifungal therapy for many months or years, many experience
significant drug side effects, and some experience drug resistance. Patients with either
allergic bronchopulmonary aspergillosis (ABPA) or severe asthma with fungal sensitization can
improve with itraconazole treatment, but relapses are common, and itraconazole affects
corticosteroid metabolism and has the potential to worsen steroid side effects. ABPA requires
long-term treatment because Aspergillus airway colonization is difficult to eradicate and
quickly recurs when treatment is stopped. Immunocompromised patients are especially
vulnerable to invasive aspergillosis where the mortality rate is often 50%, even with
antifungal treatment. Clearly, therefore, new treatment approaches are needed for lung
diseases caused by A. fumigatus, and we are proposing an approach based on prevention of
binding to airway mucins. Adherence of A. fumigatus conidia to host tissues has been the
subject of extensive research, but little attention has been directed to Aspergillus/mucin
interactions, a surprising deficiency given the role mucins play in airway biology.

This study is an ex-vivo study in which we will collect samples of sputum from healthy
volunteers and patients with cystic fibrosis for the purpose of: a) purifying airway mucins
for plate-based binding studies and; b) ex-vivo assessment of the effects of carbohydrates on
the rheologic properties of the sputum.

Inclusion Criteria:

- Healthy control subjects:

- Age 18-65

- No history of lung disease

- Cystic fibrosis subjects:

- Age 18-65

- No history of lung disease other than cystic fibrosis

- Diagnosis of CF if sweat chloride values > 60 mM on two separate pilocarpine
iontophoresis sweat tests and/or two allelic CF-producing mutations in genetic
analysis

Exclusion Criteria:

- Use of recreational drugs within 30 days prior to enrollment

- Use of tobacco within 30 days prior to enrollment, or > 10 pack-year tobacco history

- Pregnant or lactating females