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Human Lung Responses to Respiratory Pathogens

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01967628
Recruitment Status : Completed
First Posted : October 23, 2013
Results First Posted : March 29, 2018
Last Update Posted : March 29, 2018
National Institute of Allergy and Infectious Diseases (NIAID)
Information provided by (Responsible Party):
Alicia Gerke, University of Iowa

Brief Summary:

For most individuals, the lung has a remarkable ability to deal with exposure to a variety of inhaled bacteria. Some individuals, however, do have recurrent bacterial infections, usually in the form of acute or chronic bronchitis and, in some instances, pneumonia. The reasons for this variability in bacterial infections between otherwise healthy subjects, between types of lung disease, and within the same type of lung disease are poorly understood.

Variability in susceptibility to bacterial infections is partially explained by differences in exposure to infectious agents, genetic susceptibility and innate (or early) immune responses. It is of interest that the incidence and severity of bacterial infections is greatest during the winter months. Other than viral infections, there are few variables that change with season. Vitamin D is one known immune modulator with a seasonal periodicity. The hypothesis of this study is that levels of vitamin D are an important determinant of the innate defense of the lung against inhaled bacteria. The investigators further postulate that vitamin D has effects on the innate immune function of both alveolar macrophages and lung epithelial cells.

Condition or disease Intervention/treatment Phase
Respiratory Infection Dietary Supplement: Vitamin D3 (cholecalciferol) Dietary Supplement: Placebo Sugar Pill Phase 1 Phase 2

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 98 participants
Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: Triple (Participant, Care Provider, Investigator)
Primary Purpose: Basic Science
Official Title: Human Lung Responses to Respiratory Pathogens
Study Start Date : June 2007
Actual Primary Completion Date : July 2010
Actual Study Completion Date : October 2010

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Vitamin D

Arm Intervention/treatment
Experimental: Vitamin D3 (cholecalciferol)
Vitamin D3 (1000 international units) daily for 3 months.
Dietary Supplement: Vitamin D3 (cholecalciferol)
Placebo Comparator: Sugar capsule
Placebo comparator made of sugar in a capsule
Dietary Supplement: Placebo Sugar Pill

Primary Outcome Measures :
  1. Antimicrobial Activity by Airway Surface Liquid (ASL) as Measured by Relative Light Units (RLU) [ Time Frame: 3 months ]
    We investigated the effect of vitamin D3 supplementation on airway surface liquid antimicrobial activity using a bioluminescent bacterial challenge. We challenged airway surface liquid samples with bioluminescent bacteria and measured live bacteria by relative light units (RLU) after 2 minutes as a surrogate of antimicrobial activity. We interpreted a reduction in live bacteria after challenge in relative light units as increased antimicrobial activity

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 60 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

Signed informed consent form Age 18 - 60 Healthy nonsmoker, healthy smoker Forced expiratory volume in 1 second (for smokers) > 60% predicted.

Exclusion Criteria:

  • Pregnant or breastfeeding
  • Medications (with the exception of hormonal birth control, thyroid medication or prespecified over the counter medications), including multi-vitamins and any preparation that contains vitamin D
  • Asthma
  • Heart disease
  • Diabetes
  • Previous positive tuberculin skin test, or previous diagnosis of tuberculosis
  • Recent respiratory tract infection
  • History of multiple bouts of pneumonia
  • Allergies to caines, atropine, or a history of adverse reaction to narcotics
  • Other factors that increase the risk of bronchoscopy
  • Evidence of acute bronchitis within the past 2 weeks

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT01967628

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United States, Iowa
University of Iowa
Iowa City, Iowa, United States, 52242
Sponsors and Collaborators
University of Iowa
National Institute of Allergy and Infectious Diseases (NIAID)
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Principal Investigator: Alicia K Gerke, MD University of Iowa
Publications automatically indexed to this study by Identifier (NCT Number):
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Responsible Party: Alicia Gerke, Assistant Professor, University of Iowa Identifier: NCT01967628    
Other Study ID Numbers: DMID 06-0003
N01AI30040-11-0-0 ( U.S. NIH Grant/Contract )
First Posted: October 23, 2013    Key Record Dates
Results First Posted: March 29, 2018
Last Update Posted: March 29, 2018
Last Verified: February 2018
Keywords provided by Alicia Gerke, University of Iowa:
Vitamin D
Respiratory infection
Innate immunity
Additional relevant MeSH terms:
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Respiratory Tract Infections
Respiratory Tract Diseases
Vitamin D
Growth Substances
Physiological Effects of Drugs
Bone Density Conservation Agents
Calcium-Regulating Hormones and Agents