HealthyNCT07625111
Effect of Smoking and Time of Day on Eosinophils
A study testing Smoking for 4 hours in people with Healthy, run by Marek Lommatzsch at 1 site in Germany.
Trial summary
The study investigates the effect of acute smoking and time of day on blood eosinophils in chronic smokers. Chronic cigarette smokers without chronic respiratory diseases smoking at least 8 cigarettes per day and never-smoking controls are examined. Read more about this study
- Who is it for?
- Ages 18 to 50 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy
- What is being tested?
- Smoking for 4 hours
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 20 participants
- Where
- 1 siteGermany
- Study dates
- 7 Feb 2026to 6 Dec 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 50 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Healthy current smokers
- Age between 18-50 years
- Smoking of at least 8 cigarettes/day
Who cannot join
- Chronic respiratory diseases
- Any treatment with corticosteroids or other immunosuppressants
- Any acute illness
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Johann C. Virchow, Prof. contact
Germany1 site, 1 recruiting
- Recruiting
University of Rostock
Rostock, 18057
Marek Prof. Lommatzsch, Prof., +49-381-494-7461, marek.lommatzsch@med.uni-rostock.de
Johann C Virchow, Prof., +49-381-494-7461
About this study
Official title: Effects of Acute Smoking and Time of Day on Blood Eosinophils in Humans
The study investigates the effect of acute smoking and time of day on blood eosinophils in chronic smokers. Chronic cigarette smokers without chronic respiratory diseases smoking at least 8 cigarettes per day and never-smoking controls are examined. Blood eosinophil counts and surface molecules are measured at 8 and 12 am in both groups. In smokers, two measurements are performed (at least 4 weeks apart): one measurement with no smoking between 8 and 12 am, and another measurement with smoking of 8 cigarettes between 8 and 12 am.
Read the detailed description
20 chronic cigarette smokers without chronic respiratory diseases smoking at least 8 cigarettes per day and 20 never-smoking controls are recruited. Blood eosinophil counts and surface molecules are measured at 8 and 12 am in both groups. In smokers, two measurements are performed (at least 4 weeks apart, cross-over design): one measurement with no smoking between 8 and 12 am, and another measurement with smoking of 8 cigarettes between 8 and 12 am. The effects of the time of day (comparing 8 and 12 am) and the effects of acute smoking (comparing the effects of no smoking or acute smoking at 12 am) on blood eosinophil counts and surface molecules (using flow cytometry) are analyzed. Additional parameters examined: lung function, exhaled nitric oxide, total and specific IgE in serum.
- Conditions
- Healthy
- Being tested
- Smoking for 4 hours
- Keywords
- Eosinophils, smoking, time of day, blood, flow cytometry
- Medical subject headings
- Smoking
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Smoking for 4 hoursOther
Smoking of 8 cigarettes in 4 hours
| Study group | Role | What they receive |
|---|---|---|
| A: Smoking of 8 cigarettes in 4 hours | Experimental | Smoking Receives: Other: Smoking for 4 hours |
| B: No smoking for 4 hours | No intervention | No Smoking |
What is being measured
The primary outcome is the main question the study is designed to answer.
Blood eosinophil counts
Blood eosinophil counts in cells/µl blood
Measured: 8 am (baseline) and 12 am (follow-up after intervention)
Secondary outcomes (1)
Blood eosinophil surface molecules
Blood eosinophil surface molecules (such as CD62L or CD294), measured using flow cytometry
Measured: 8 am (baseline) and 12 am (follow-up after intervention)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 Jun 2026
- Study start7 Feb 2026
- Primary completion30 Jun 2026 (estimated)
- Study completion6 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for HealthyStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- Intervention: Smoking. Intervention: Time of day.
- Masking
- None (open label)
- Enrolment
- 20 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Marek Lommatzsch
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, Marek Lommatzsch, University of Rostock
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07625111
- Sponsor's protocol ID
- Smoke-Time-Eosinophils
- Status last verified
- Jun 2026
- First submitted
- 26 May 2026
- Last updated
- 4 Jun 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 4 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of Acute Smoking and Time of Day on Blood Eosinophils in Humans
- ClinicalTrials.gov ID
- NCT07625111
- Acronym / sponsor ID
- Smoke-Time-Eosinophils
- Conditions
- Healthy
- Keywords
- Eosinophils, smoking, time of day, blood, flow cytometry
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 20 participants (estimated)
- Lead sponsor
- Marek LommatzschUniversity, hospital or other
- Study start
- 7 Feb 2026 (actual)
- Primary completion
- 30 Jun 2026 (estimated)
- Study completion
- 6 Dec 2026 (estimated)
- First posted
- 4 Jun 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The study investigates the effect of acute smoking and time of day on blood eosinophils in chronic smokers. Chronic cigarette smokers without chronic respiratory diseases smoking at least 8 cigarettes per day and never-smoking controls are examined. Blood eosinophil counts and surface molecules are measured at 8 and 12 am in both groups. In smokers, two measurements are performed (at least 4 weeks apart): one measurement with no smoking between 8 and 12 am, and another measurement with smoking of 8 cigarettes between 8 and 12 am.
Detailed description
20 chronic cigarette smokers without chronic respiratory diseases smoking at least 8 cigarettes per day and 20 never-smoking controls are recruited. Blood eosinophil counts and surface molecules are measured at 8 and 12 am in both groups. In smokers, two measurements are performed (at least 4 weeks apart, cross-over design): one measurement with no smoking between 8 and 12 am, and another measurement with smoking of 8 cigarettes between 8 and 12 am. The effects of the time of day (comparing 8 and 12 am) and the effects of acute smoking (comparing the effects of no smoking or acute smoking at 12 am) on blood eosinophil counts and surface molecules (using flow cytometry) are analyzed. Additional parameters examined: lung function, exhaled nitric oxide, total and specific IgE in serum.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- Intervention: Smoking. Intervention: Time of day.
| Arm | Type | Receives |
|---|---|---|
| A: Smoking of 8 cigarettes in 4 hours | Experimental | Other: Smoking for 4 hoursSmoking |
| B: No smoking for 4 hours | No intervention | –No Smoking |
Who may qualify
- Ages
- 18 to 50 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (3 listed)
- Healthy current smokers
- Age between 18-50 years
- Smoking of at least 8 cigarettes/day
Key exclusion criteria (3 listed)
- Chronic respiratory diseases
- Any treatment with corticosteroids or other immunosuppressants
- Any acute illness
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Smoking for 4 hoursSmoking of 8 cigarettes in 4 hours | Other | A: Smoking of 8 cigarettes in 4 hours |
Primary outcome
Blood eosinophil counts
Time frame: 8 am (baseline) and 12 am (follow-up after intervention)
Blood eosinophil counts in cells/µl blood
1 secondary outcome
Blood eosinophil surface molecules
Time frame: 8 am (baseline) and 12 am (follow-up after intervention)
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 4 Jun 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Johann C. Virchow, Prof. contact
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Smoking for 4 hours in people with Healthy, run by Marek Lommatzsch at 1 site in Germany.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 4 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Germany. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Marek Prof. Lommatzsch, Prof. (+49-381-494-7461, marek.lommatzsch@med.uni-rostock.de), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Blood eosinophil counts (time frame: 8 am (baseline) and 12 am (follow-up after intervention)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 4 Jun 2026.