Hookworm InfectionNCT00603889
Development of a Skin Test for the Na-ASP-2 Hookworm Antigen
A study testing Na-ASP-2 Skin Test Reagent in people with Hookworm Infection and Allergy, run by Albert B. Sabin Vaccine Institute at 1 site in United States.
Trial summary
Na-ASP-2 is a protein expressed during the larval stage of the N. americanus hookworm life cycle. In a clinical study in previously hookworm-infected adults in Brazil, this protein induced urticarial reactions (rash) in a subset of volunteers. Read more about this study
- Who is it for?
- Ages 18 to 45 yearsHealthy volunteers can take part
- Conditions the study is for
- Hookworm Infection, Allergy
- What is being tested?
- Na-ASP-2 Skin Test Reagent
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 12 participants
- Where
- 1 siteUnited States
- Study dates
- Mar 2008to May 2008
- Phase
- Interventional
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
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 45 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Males or females between 18 and 45 years of age, inclusive.
- Good general health as determined by means of the screening procedure.
- Willingness to participate in the study as evidenced by signing the informed consent document.
Who cannot join
- History of previous infection with hookworm.
- Prior extensive and continuous travel, work, or residence (> 1 month) in a hookworm-endemic region.
- Pregnancy as determined by a positive urine hCG test (if female).
- Evidence of clinically significant neurologic, cardiac, pulmonary, hepatic, rheumatologic, autoimmune, or renal disease by history or physical examination.
- Behavioral, cognitive, or psychiatric disease that in the opinion of the investigator affects the ability of the volunteer to understand and cooperate with the study protocol.
- Other condition that in the opinion of the investigator would jeopardize the safety or rights of a volunteer participating in the trial or would render the subject unable to comply with the protocol.
Show all 15Show fewer
- Participation in an investigational vaccine or drug trial within 14 days of starting this study.
- Volunteer has had medical, occupational, or family problems as a result of alcohol or illicit drug use during the past 12 months.
- History of a severe allergic reaction or anaphylaxis.
- Known immunodeficiency syndrome.
- Use of corticosteroids (excluding topical or nasal) or immunosuppressive drugs within 30 days of starting this study.
- History of a surgical splenectomy.
- Extensive dermatitis precluding skin testing
- Current use of a beta blocker (oral or topical) or anti-histamine medication. A volunteer may participate in the study if they agree to withhold use of an anti-histamine for at least 5 days prior to application of the skin test.
- Use of a tricyclic anti-depressant within the past month.
Trial locations and contacts
1 site in 1 country.
United States1 site
GWUMC Clinical Trials Unit
Washington D.C., District of Columbia, 20037
About this study
Official title: Development of a Skin Test to Detect Immediate-type Hypersensitivity to the Experimental Na-ASP-2 Hookworm Antigen
Na-ASP-2 is a protein expressed during the larval stage of the N. americanus hookworm life cycle. In a clinical study in previously hookworm-infected adults in Brazil, this protein induced urticarial reactions (rash) in a subset of volunteers. This study will evaluate solutions of varying concentrations of the protein in both a skin prick-puncture and intradermal test that will eventually be used to screen volunteers living in hookworm endemic areas who are being considered as potential participants in vaccine trials, to reduce the potential of inducing allergic reactions in those vaccinated with the Na-ASP-2 Hookworm Vaccine.
Read the detailed description
- Study site: George Washington University Medical Center
- Number of participants: up to 15
- Study duration: up to 3 months; each participant will undergo a minimum of one screening visit and one study visit.
- Each participant will have both skin prick-puncture and intradermal skin tests applied on the same study day. The prick-puncture and intradermal tests will be applied sequentially to the volar aspects of the participant's forearms:
- Skin prick-puncture: four different concentrations of Na-ASP-2 solution (1, 10, 100, and 1000 μg/mL) will be applied simultaneously in duplicate, to the left forearm.
- Intradermal: three different concentrations of Na-ASP-2 (10, 100, and 1000 μg/mL) will be injected simultaneously, in duplicate, to the right forearm.
- Allergen diluent and histamine solutions will be utilized as the negative and positive controls, respectively, for both the skin prick-puncture and intradermal tests.
- Participants will be observed in the study clinic for at least 30 minutes following application of the skin tests, and will be contacted via telephone 2 days following skin testing.
- Sizes of the wheal and erythema reactions for each application will be recorded and graded in comparison to the histamine positive control reaction.
- Each participant will have blood collected via venipuncture (a maximum of 25 mL) immediately prior to application of the skin tests, in order to measure antibodies (particularly IgG and IgE) to Na-ASP-2 using an ELISA procedure.
- Conditions
- Hookworm Infection, Allergy
- Being tested
- Na-ASP-2 Skin Test Reagent
- Keywords
- Hookworm, Allergy, Vaccine, Skin test
- Medical subject headings
- Hookworm Infections, Hypersensitivity, Ancylostomiasis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Na-ASP-2 Skin Test ReagentBiological
Na-ASP-2 Hookworm Skin Test Reagent, 1-1000 mcg/mL solution
| Study group | Role | What they receive |
|---|---|---|
| Na-ASP-2 Hookworm Antigen Skin Test | Experimental | All participants will have the same number of concentrations of the Na-ASP-2 skin test reagent applied to their arms, using both the prick-puncture and intradermal techniques. Receives: Biological: Na-ASP-2 Skin Test Reagent |
What is being measured
The primary outcome is the main question the study is designed to answer.
100 Mcg/ml Na-ASP-2 Prick-puncture Skin Test
Mean grade of wheal reaction after 2 applications of the skin test reagent per participant. For each skin test reaction, the grade of the test was determined based on the mean of the longest and orthogonal diameters, which was then compared to the equivalent measurements of a histamine solution positive control that was applied at the same time as the test. Grading was as follows:
0 no discernible wheal
- < ½ histamine diameter
- ≥ ½ histamine; < histamine diameter
- = size of histamine control ± 1 mm
- > histamine diameter; < 2x diameter
- ≥ 2x histamine control
Measured: 15 minutes after skin test application
Secondary outcomes (3)
1000 Mcg/ml Na-ASP-2 Prick-puncture Skin Test
Mean grade of wheal reaction after 2 applications of the skin test reagent per participant. For each skin test reaction, the grade of the test was determined based on the mean of the longest and orthogonal diameters, which was then compared to the equivalent measurements of a histamine solution positive control that was applied at the same time as the test. Grading was as follows:
0 no discernible wheal
- < ½ histamine diameter
- ≥ ½ histamine; < histamine diameter
- = size of histamine control ± 1 mm
- > histamine diameter; < 2x diameter
- ≥ 2x histamine control
Measured: 15 minutes after skin test application
100 Mcg/ml Na-ASP-2 Intradermal Skin Test
Mean grade of wheal reaction after 2 applications of the skin test reagent per participant. For each skin test reaction, the grade of the test was determined based on the mean of the longest and orthogonal diameters, which was then compared to the equivalent measurements of a histamine solution positive control that was applied at the same time as the test. Grading was as follows:
0 no discernible wheal
- < ½ histamine diameter
- ≥ ½ histamine; < histamine diameter
- = size of histamine control ± 1 mm
- > histamine diameter; < 2x diameter
- ≥ 2x histamine control
Measured: 15 minutes after skin test application
1000 Mcg/ml Na-ASP-2 Intradermal Skin Test
Mean grade of wheal reaction after 2 applications of the skin test reagent per participant. For each skin test reaction, the grade of the test was determined based on the mean of the longest and orthogonal diameters, which was then compared to the equivalent measurements of a histamine solution positive control that was applied at the same time as the test. Grading was as follows:
0 no discernible wheal
- < ½ histamine diameter
- ≥ ½ histamine; < histamine diameter
- = size of histamine control ± 1 mm
- > histamine diameter; < 2x diameter
- ≥ 2x histamine control
Measured: 15 minutes after skin test application
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 Jan 2008 (estimated)
- Study startMar 2008
- Primary completionMay 2008
- Study completionMay 2008
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for Hookworm InfectionStudies 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
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 12 participants (actual)
Sponsor and investigators
- Lead sponsor
- Albert B. Sabin Vaccine Institute
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- David Parenti, MD, Principal investigator, GWUMC Medical Faculty Associates
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00603889
- Sponsor's protocol ID
- SVI-07-02
- Status last verified
- Jan 2012
- First submitted
- 17 Jan 2008
- Last updated
- 23 Feb 2012
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
Publications
Fujiwara RT, Bethony J, Bueno LL, Wang Y, Ahn SY, Samuel A, Bottazzi ME, Hotez P, Mendez S. Immunogenicity of the hookworm Na-ASP-2 vaccine candidate: characterization of humoral and cellular responses after vaccination in the Sprague Dawley rat. Hum Vaccin. 2005 May-Jun;1(3):123-8. doi: 10.4161/hv.1.3.1924. Epub 2005 May 20.
PubMed 17012856Goud GN, Bottazzi ME, Zhan B, Mendez S, Deumic V, Plieskatt J, Liu S, Wang Y, Bueno L, Fujiwara R, Samuel A, Ahn SY, Solanki M, Asojo OA, Wang J, Bethony JM, Loukas A, Roy M, Hotez PJ. Expression of the Necator americanus hookworm larval antigen Na-ASP-2 in Pichia pastoris and purification of the recombinant protein for use in human clinical trials. Vaccine. 2005 Sep 15;23(39):4754-64. doi: 10.1016/j.vaccine.2005.04.040.
PubMed 16054275Diemert DJ, Bethony JM, Hotez PJ. Hookworm vaccines. Clin Infect Dis. 2008 Jan 15;46(2):282-8. doi: 10.1086/524070.
PubMed 18171264
Study at a glance
From the registry record, last updated by the sponsor on 23 Feb 2012. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Development of a Skin Test to Detect Immediate-type Hypersensitivity to the Experimental Na-ASP-2 Hookworm Antigen
- ClinicalTrials.gov ID
- NCT00603889
- Acronym / sponsor ID
- SVI-07-02
- Conditions
- Hookworm Infection, Allergy
- Keywords
- Hookworm, Allergy, Vaccine, Skin test
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 12 participants (actual)
- Lead sponsor
- Albert B. Sabin Vaccine InstituteUniversity, hospital or other
- Study start
- Mar 2008
- Primary completion
- May 2008 (actual)
- Study completion
- May 2008 (actual)
- First posted
- 29 Jan 2008 (estimated)
- Results
- Posted 23 Feb 2012
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Na-ASP-2 is a protein expressed during the larval stage of the N. americanus hookworm life cycle. In a clinical study in previously hookworm-infected adults in Brazil, this protein induced urticarial reactions (rash) in a subset of volunteers. This study will evaluate solutions of varying concentrations of the protein in both a skin prick-puncture and intradermal test that will eventually be used to screen volunteers living in hookworm endemic areas who are being considered as potential participants in vaccine trials, to reduce the potential of inducing allergic reactions in those vaccinated with the Na-ASP-2 Hookworm Vaccine.
Detailed description
- Study site: George Washington University Medical Center
- Number of participants: up to 15
- Study duration: up to 3 months; each participant will undergo a minimum of one screening visit and one study visit.
- Each participant will have both skin prick-puncture and intradermal skin tests applied on the same study day. The prick-puncture and intradermal tests will be applied sequentially to the volar aspects of the participant's forearms:
- Skin prick-puncture: four different concentrations of Na-ASP-2 solution (1, 10, 100, and 1000 μg/mL) will be applied simultaneously in duplicate, to the left forearm.
- Intradermal: three different concentrations of Na-ASP-2 (10, 100, and 1000 μg/mL) will be injected simultaneously, in duplicate, to the right forearm.
- Allergen diluent and histamine solutions will be utilized as the negative and positive controls, respectively, for both the skin prick-puncture and intradermal tests.
- Participants will be observed in the study clinic for at least 30 minutes following application of the skin tests, and will be contacted via telephone 2 days following skin testing.
- Sizes of the wheal and erythema reactions for each application will be recorded and graded in comparison to the histamine positive control reaction.
- Each participant will have blood collected via venipuncture (a maximum of 25 mL) immediately prior to application of the skin tests, in order to measure antibodies (particularly IgG and IgE) to Na-ASP-2 using an ELISA procedure.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Na-ASP-2 Hookworm Antigen Skin Test | Experimental | Biological: Na-ASP-2 Skin Test ReagentAll participants will have the same number of concentrations of the Na-ASP-2 skin test reagent applied to their arms, using both the prick-puncture and intradermal techniques. |
Who may qualify
- Ages
- 18 to 45 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (3 listed)
- Males or females between 18 and 45 years of age, inclusive.
- Good general health as determined by means of the screening procedure.
- Willingness to participate in the study as evidenced by signing the informed consent document.
Key exclusion criteria (15 listed)
- History of previous infection with hookworm.
- Prior extensive and continuous travel, work, or residence (> 1 month) in a hookworm-endemic region.
- Pregnancy as determined by a positive urine hCG test (if female).
- Evidence of clinically significant neurologic, cardiac, pulmonary, hepatic, rheumatologic, autoimmune, or renal disease by history or physical examination.
- Behavioral, cognitive, or psychiatric disease that in the opinion of the investigator affects the ability of the volunteer to understand and cooperate with the study protocol.
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 |
|---|---|---|
| Na-ASP-2 Skin Test ReagentNa-ASP-2 Hookworm Skin Test Reagent, 1-1000 mcg/mL solution | Biological | Na-ASP-2 Hookworm Antigen Skin Test |
Primary outcome
100 Mcg/ml Na-ASP-2 Prick-puncture Skin Test
Time frame: 15 minutes after skin test application
Mean grade of wheal reaction after 2 applications of the skin test reagent per participant. For each skin test reaction, the grade of the test was determined based on the mean of the longest and orthogonal diameters, which was then compared to the equivalent measurements of a histamine solution positive control that was applied at the same time as the test. Grading was as follows: 0 no discernible wheal 1. < ½ histamine diameter 2. ≥ ½ histamine; < histamine diameter 3. = size of histamine control ± 1 mm 4. > histamine diameter; < 2x diameter 5. ≥ 2x histamine control
3 secondary outcomes
1000 Mcg/ml Na-ASP-2 Prick-puncture Skin Test
Time frame: 15 minutes after skin test application
100 Mcg/ml Na-ASP-2 Intradermal Skin Test
Time frame: 15 minutes after skin test application
1000 Mcg/ml Na-ASP-2 Intradermal Skin Test
Time frame: 15 minutes after skin test application
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 23 Feb 2012.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Background: PubMed 17012856Fujiwara RT, Bethony J, Bueno LL, Wang Y, Ahn SY, Samuel A, Bottazzi ME, Hotez P, Mendez S. Immunogenicity of the hookworm Na-ASP-2 vaccine candidate: characterization of humoral and cellular responses after vaccination in the Sprague Dawley rat. Hum Vaccin. 2005 May-Jun;1(3):123-8. doi: 10.4161/hv.1.3.1924. Epub 2005 May 20.
- Background: PubMed 16054275Goud GN, Bottazzi ME, Zhan B, Mendez S, Deumic V, Plieskatt J, Liu S, Wang Y, Bueno L, Fujiwara R, Samuel A, Ahn SY, Solanki M, Asojo OA, Wang J, Bethony JM, Loukas A, Roy M, Hotez PJ. Expression of the Necator americanus hookworm larval antigen Na-ASP-2 in Pichia pastoris and purification of the recombinant protein for use in human clinical trials. Vaccine. 2005 Sep 15;23(39):4754-64. doi: 10.1016/j.vaccine.2005.04.040.
- Background: PubMed 18171264Diemert DJ, Bethony JM, Hotez PJ. Hookworm vaccines. Clin Infect Dis. 2008 Jan 15;46(2):282-8. doi: 10.1086/524070.
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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. This study is not recruiting at the moment.
David Parenti, MD principal investigator
GWUMC Medical Faculty Associates
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Na-ASP-2 Skin Test Reagent in people with Hookworm Infection and Allergy, run by Albert B. Sabin Vaccine Institute at 1 site in United States.
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 15 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: finished, as of the sponsor's last update on 23 Feb 2012. 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 United States. 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?
Yes. Results are posted in the registry (first posted 23 Feb 2012). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
100 Mcg/ml Na-ASP-2 Prick-puncture Skin Test (time frame: 15 minutes after skin test application). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT00603889, which also lists 3 linked publications.
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 23 Feb 2012.