Patient case (clinical description): A 30-year-old man who is a computer scientist came to the clinic with the lab result stating azoospermia.  The patient is sexually active with his wife and does not use any contraception methods.  They have been trying to conceive for the past year with no success.  The patient has a past medical history of recurrent pneumonia, shortness of breath, and  persistent cough that produces large amounts of thick sputum. The patient had multiple lung infections during childhood. He does not smoke, use illicit drugs or alcohol.  The patient has no history of other medical conditions including allergies or any kind of surgery.  On physical examination, the digits show clubbing.  An ultrasound shows bilateral absence of the vas deferens, and FEV1 was 75% on the respiratory function test.

Patient's own account: I'm a 30-year-old computer scientist. I did some lab tests that came back quite alarming, stating that I have azoospermia?! I'm sexually active with my wife and we don't use contraception. We've been trying to have a child for the past year. I have a medical history of pneumonia and shortness of breath and regular wet cough. I had several lung infections when I was a kid. That's why I'm very careful and don't smoke, do drugs, or drink. I don't have other medical conditions including allergies or any kind of surgery. The doctor did the clubbing test on my fingers, which was positive. I also did an ultrasound and it showed that I'm missing the tubes that carry sperm around. I also had a 75% for my respiratory function test.

Clinical trial: Study of Dust Mite Inhalation in Humans

Eligibility criteria:
Inclusion Criteria:

          1. A history of episodic wheezing, chest tightness, or shortness of breath consistent
             with asthma, or physician diagnosed asthma.

          2. Specific allergy to house dust mite Dermatophagoides farinae confirmed by positive
             immediate skin test response.

          3. 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
             (98-CEMLB-293) that is already approved by the UNC IRB.

          4. FEV1 of at least 80% of predicted and FEV1/FVC ratio of at least .70 (without use of
             bronchodilating medications for 12 hours), consistent with lung function of persons
             with mild episodic or mild persistent asthma.

        Exclusion Criteria:

          1. Any chronic medical condition considered by the PI as a contraindication to the
             exposure study including significant cardiovascular disease, diabetes requiring
             medication, chronic renal disease, or chronic thyroid disease.

          2. Subjects with a history of immunologic disease, or undergoing therapeutic immune
             suppression for cancer or other diseases.

          3. Physician directed emergency treatment for an asthma exacerbation within the preceding
             12 months.

          4. Use of systemic steroid therapy within the preceding 12 months for asthma or the
             following asthma symptoms; cough, wheeze, shortness of breath.

          5. Use of inhaled steroids, cromolyn or leukotriene inhibitors (Montelukast or
             Zafirlukast) within the past month (except for use of cromolyn exclusively prior to
             exercise).

          6. Use of daily theophylline within the past month.

          7. Use of medications that might alter the response to methacholine or antigen challenge
             including anti-inflammatory and anti-histamine agents within one week of challenge.

          8. Subjects using tricyclic antidepressants such as doxepin and MAO inhibitors.

          9. Subjects using beta-adrenergic blockers or any other medications known to interfere
             with the treatment of anaphylaxis.

         10. Inability to withhold inhaled or oral bronchodilating medications for 12 hours prior
             to allergen challenge.

         11. Pregnancy (positive urine pregnancy test at the baseline visit) or nursing a baby.
             Pregnant women are excluded due to the risk of fetal exposure to radiation.

         12. Women of child bearing potential who are not using dependable contraception (such as
             birth control pill, IUD, estrogen patches) or who are not completely abstinent.

         13. Cigarette smoking >0.5 packs per week within the past 12 months.

         14. 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.

         15. 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.

         16. 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).

         17. Viral upper respiratory tract infection within 4 weeks of challenge.

         18. Any acute infection requiring antibiotics within 2 weeks of challenge (or 4 weeks in
             the case of azithromycin due to the prolonged half-life).

         19. Participating in any study utilizing an investigational agent within 4 weeks of this
             challenge.
No condition on gender to be admitted to the trial.
No healthy subjects accepted to join the trial.
Subject must be at least 18 Years old.
Subject must be at most 50 Years

Eligibility (NLI label): Contradiction