To Identify Persons Who Are Susceptible to WSP-induced Inflammation and Examine the Role of GSTM1 and Other Factors in This Susceptibility
Status: | Recruiting |
---|---|
Conditions: | Allergy, Asthma, Pulmonary |
Therapuetic Areas: | Otolaryngology, Pulmonary / Respiratory Diseases |
Healthy: | No |
Age Range: | 18 - 45 |
Updated: | 2/24/2019 |
Start Date: | May 2016 |
End Date: | May 2021 |
Contact: | Katherine H Mills, B.A. |
Email: | katherine_mills@med.unc.edu |
Phone: | 919-843-6598 |
Purpose: This screening protocol is designed to assess PMN (neutrophil) responsiveness to
wood smoke particles (WSP) and the effect of the GSTM1 null genotype on this response. The
researches will identify persons responsive and resistant to the inflammatory effect of WSP.
It is anticipated that the GSTM1 genotype will be a risk factor for increased response to
WSP.
wood smoke particles (WSP) and the effect of the GSTM1 null genotype on this response. The
researches will identify persons responsive and resistant to the inflammatory effect of WSP.
It is anticipated that the GSTM1 genotype will be a risk factor for increased response to
WSP.
Particulate matter (PM) is a leading cause of respiratory tract and cardiovascular disease in
the United States and world-wide. Wood smoke particles (WSP) derived from wild land and other
fires account for a significant fraction of ambient air PM. Health effects associated with
WSP include acute bronchitis, asthma exacerbation, pneumonia, cough and systemic
inflammation. While these effects are seen in both healthy and asthmatic individuals, many
studies indicate that asthmatics have increased susceptibility to the effects of WSP. Though
WSP-related effects on cardiovascular (CV) disease are less well documented, WSP do
contribute to PM levels, and PM exposure is linked to CV health effects (changes in heart
rate variability, vascular reactivity, and lipid profiles). WSP from wild land fires can
cause abrupt increases in ambient air PM 2.5 levels (mean levels ~250µg/m3, peak levels >1000
µg/m3). Avoidance of rapidly increasing PM air pollution due to wild land fires is not
feasible, as many people cannot leave the burn region.
This is a screening protocol to ensure that there ultimately will be adequate subjects
available for testing gamma tocopherol in an appropriate population. It will identify
volunteers who have a ≥10% increase in %PMNs following WSP challenge over baseline values
(SA1). This screening procedure will identify various risk factors that may increase risk of
experiencing airway inflammation and related adverse health outcomes following WSP exposure.
The GSTM1- genotype is a risk factor that has been extensively explored. Researchers at the
CEMALB have reported that GSTM1- healthy volunteers (HVs) have increased inflammatory and
systemic responses to O3 and various components of PM (LPS70 and Diesel exhaust particles).
Using the 10% increase in %PMNs to define PMN responsiveness, results showed that GSTM1-
volunteers had a 13 fold higher risk of being PMN responders to 0.06 ppm O3. When examining
%PMNs as a continuous measure, it was observed that GSTM1- volunteers have increased airway
PMN response O3 as well as increased airway and systemic PMN response to LPS70.
The researchers at the CEMALB have also examined various response features of 27 individuals
(13 healthy, 4 allergic non asthmatics, 10 allergic asthmatics) defined as being responsive
(R, n=18) or non-responsive (NR, n=9) to O3 based on airway PMN influx (%PMNs). Among the
factors explored were inflammatory responses, baseline characteristics and gene expression
profiles in recovered sputum cells. The researchers have also observed that within
individuals, PMN response to O3 and LPS correlate, and anticipate that WSP will induce
inflammatory responses via mechanisms similar to those for these pollutants.
the United States and world-wide. Wood smoke particles (WSP) derived from wild land and other
fires account for a significant fraction of ambient air PM. Health effects associated with
WSP include acute bronchitis, asthma exacerbation, pneumonia, cough and systemic
inflammation. While these effects are seen in both healthy and asthmatic individuals, many
studies indicate that asthmatics have increased susceptibility to the effects of WSP. Though
WSP-related effects on cardiovascular (CV) disease are less well documented, WSP do
contribute to PM levels, and PM exposure is linked to CV health effects (changes in heart
rate variability, vascular reactivity, and lipid profiles). WSP from wild land fires can
cause abrupt increases in ambient air PM 2.5 levels (mean levels ~250µg/m3, peak levels >1000
µg/m3). Avoidance of rapidly increasing PM air pollution due to wild land fires is not
feasible, as many people cannot leave the burn region.
This is a screening protocol to ensure that there ultimately will be adequate subjects
available for testing gamma tocopherol in an appropriate population. It will identify
volunteers who have a ≥10% increase in %PMNs following WSP challenge over baseline values
(SA1). This screening procedure will identify various risk factors that may increase risk of
experiencing airway inflammation and related adverse health outcomes following WSP exposure.
The GSTM1- genotype is a risk factor that has been extensively explored. Researchers at the
CEMALB have reported that GSTM1- healthy volunteers (HVs) have increased inflammatory and
systemic responses to O3 and various components of PM (LPS70 and Diesel exhaust particles).
Using the 10% increase in %PMNs to define PMN responsiveness, results showed that GSTM1-
volunteers had a 13 fold higher risk of being PMN responders to 0.06 ppm O3. When examining
%PMNs as a continuous measure, it was observed that GSTM1- volunteers have increased airway
PMN response O3 as well as increased airway and systemic PMN response to LPS70.
The researchers at the CEMALB have also examined various response features of 27 individuals
(13 healthy, 4 allergic non asthmatics, 10 allergic asthmatics) defined as being responsive
(R, n=18) or non-responsive (NR, n=9) to O3 based on airway PMN influx (%PMNs). Among the
factors explored were inflammatory responses, baseline characteristics and gene expression
profiles in recovered sputum cells. The researchers have also observed that within
individuals, PMN response to O3 and LPS correlate, and anticipate that WSP will induce
inflammatory responses via mechanisms similar to those for these pollutants.
Inclusion Criteria
1. Age 18-45 of both genders
2. Negative pregnancy test for females who are not s/p hysterectomy with oopherectomy
3. Calculated 10 year risk of CVD by the Framingham risk score of <5%
Specific for Healthy Volunteers
4. No history of episodic wheezing, chest tightness or shortness of breath consistent
with asthma, or physician diagnoses asthma.
5. Negative methacholine test, by the method used in a separate screening protocol.
6. FEV1 of at least 80% of predicted and FEV1/FVC ratio of at least .70
Specific for Allergic Asthmatic Volunteers
7. History of episodic wheezing, chest tightness, or shortness of breath consistent with
asthma, or physician diagnosed asthma.
8. Positive methacholine test. A positive test is defined as a provocative concentration
of methacholine of 10 mg/ml or less producing a 20% fall in FEV1 (PC20 methacholine)
by the method used in a separate screening protocol OR a POST-bronchodilator increase
in FEV1 of at least 12%, OR a clinical history of asthma after the age of 6.
9. FEV1 of at least 75% of predicted without use of short acting bronchodilating
medications for 12 hours, consistent with lung function of persons with no more than
mild episodic or mild persistent asthma.
10. Allergic sensitization to at least one of the following allergen preparations: (House
Dust Mite f, House dust mite p, Cockroach, Tree mix, Grass Mix, Weed Mix, Mold Mix 1,
Mold Mix 2, Rat, Mouse, Guinea Pig, Rabbit, Cat or Dog) confirmed by positive
immediate skin test response; or a clinical history consistent with seasonal or
perennial allergy symptoms.
11. Subjects must be willing to avoid caffeine for 12 hours prior to all visits.
Methacholine challenge and allergy skin testing are performed as part of IRB98-0799,
which a subject must complete in order to be considered for this protocol.
Exclusion Criteria
Patients who meet any of these criteria are not eligible for enrollment as study
participants:
1. Clinical contraindications:
1. Any chronic medical condition considered by the PI as a contraindication to the
exposure study including significant cardiovascular disease, diabetes, chronic
renal disease, chronic thyroid disease, history of chronic
infections/immunodeficiency, history of tuberculosis.
2. Viral upper respiratory tract infection within 4 weeks of challenge.
3. Any acute infection requiring antibiotics within 4 weeks of exposure or fever of
unknown origin within 4 weeks of challenge.
4. Abnormal physical findings at the baseline visit, including but not limited to
abnormalities on auscultation, temperature of 37.8° C, Systolic BP > 150mm Hg or
< 85 mm Hg; or Diastolic BP > 90 mm Hg or < 50 mm Hg, or pulse oximetry
saturation reading less than 94%.
5. Unwillingness to use reliable contraception if sexually active (IUD, birth
control pills/patch, condoms).
6. Use of immunosuppressive or anticoagulant medications including routine use of
NSAIDS. Oral contraceptives are acceptable, as are Antidepressants and other
medications may be permitted if, in the opinion of the investigator, the
medication will not interfere with the study procedures or compromise safety and
if the dosage has been stable for 1 month
7. Orthopedic in juries or impediments that would preclude bicycle or treadmill
exercise.
8. Mental illness or history of drug or alcohol abuse that, in the opinion of the
investigator, would interfere with the participant's ability to comply with study
requirements.
9. Medications which may impact the results of the WSP exposure, interfere with any
other medications potentially used in the study (to include steroids, beta
antagonists, non-steroidal anti-inflammatory agents).
10. Inability to avoid NSAIDS, Multivitamins, Vitamin C or E or herbal medications in
the 4 days prior to the screening visit the exposure session.
11. Symptomatic allergic rhinitis or current active allergies.
12. Cigarette smoking > 1 pack per month
Specific for Healthy Volunteers
13. Physician diagnosis of asthma.
Specific for Asthmatic Volunteers
14. Physician directed emergency treatment for an asthma exacerbation within the
preceding 3 months
15. Moderate or Severe asthma
16. Exacerbation of asthma more than 2x/week which would be characteristic of a
person of moderate or severe persistent asthma as outlined in the current NHLBI
guidelines for diagnosis and management of asthma.
17. Daily requirement for albuterol due to asthma symptoms (cough, wheeze, chest
tightness) which would be characteristic of a person of moderate or severe
persistent asthma as outlined in the current NHLBI guidelines for diagnosis and
management of asthma. (Not to include prophylactic use of albuterol prior to
exercise).
18. Nighttime symptoms of cough or wheeze greater than 1x/week at baseline (not
during a clearly recognized viral induced asthma exacerbation) which would be
characteristic of a person of moderate or severe persistent asthma as outlined in
the current NHLBI guidelines for diagnosis and management of asthma
19. History of intubation for asthma
20. Use of systemic steroid therapy within the preceding 3 months for an asthma
exacerbation. All use of systemic steroids in the last year will be reviewed by a
study physician.
21. Use of inhaled steroids, cromolyn or leukotriene inhibitors (Montelukast or
Zafirkulast) except for use of cromolyn exclusively prior to exercise.
22. Use of daily theophylline within the past month
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Chapel Hill, North Carolina 27599
Phone: 919-843-6598
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