An observational study in Alpha-Gal Syndrome, sponsored by Luxembourg Institute of Health. Recruiting at 2 sites in Luxembourg. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-03-30.
Sponsored by Luxembourg Institute of Health · Observational
Tick bites can transmit pathogens, but they can also induce a food allergy to mammalian meat. The goal of this clinical trial is to follow immune response and antibody build-up in individuals bitten by a tick. Participants are invited to enroll within 48 hours after the tick removal and donate some blood. The tick is also collected and analysed. Researchers will then try to answer the following questions:
Researchers will compare a group of participants that develop IgE against the alpha-Gal sugar with participants that will not. They want to find out if there are specific immune features that differentiate the 2 groups.
Participants will:
Ticks bearing pathogens can transmit infectious diseases such as Lyme borreliosis, tick-borne encephalitis and others. Recently, a non-infectious human disease, namely the alpha-gal syndrome (AGS), was shown to be of tick origin. AGS, characterized by the presence of IgE antibodies directed against the carbohydrate galactose-α-1,3-galactose (alpha-gal or α-gal) is also known as 'red meat allergy'. Unlike the more 'classical' food allergies, symptoms are delayed and may appear several hours after ingestion of mammalian meat or dairy products, often hampering a timely clinical diagnosis.
Individuals with occupational or recreational outdoor activities often experience frequent tick bites and they have a higher risk of developing AGS. There are still many questions regarding the etiology and the development of the disease. Not every tick bite will lead to sensitization and it is presently unclear how the human immune system reacts to tick bites and why the initial events after a tick bite will either lead to a short-lived natural immune defense or shift the immune response to an uncontrolled Th2 response which potentially leads to allergic disease. Tick bites also bear the risk of pathogen transmission, and there is a clear need for monitoring tick bites for public health purposes.
The present study will investigate early peripheral immune responses in individuals bitten by a tick. The investigators hypothesize that the pathway to allergic sensitization to α-gal is already predictable from the peripheral immune response early after a tick bite and that an adequate protective defense against ticks can be distinguished from an allergic inflammatory response by discrete marker signatures shortly after the tick bite. Additionally, the investigators will collect population-based tick surveillance data which will be an important contribution to public health. The advertising of the study for recruitment purposes will be combined with information on tick avoidance and monitoring in case of a bite, thus contributing to public awareness and education.
The objectives of the study are:
i) To determine peripheral inflammatory protein and cellular as well as intracellular signatures leading to either a normal and self-limited human immune defense or to allergic sensitization; ii) To generate surveillance data on tick-related diseases (pathogens/allergy) in individuals experiencing a tick bite.
In order to achieve these objectives, the researchers will perform a deep immune analysis of blood samples collected upon a tick bite by using multi-omics and high-resolution techniques. They will longitudinally follow 100 study participants for several weeks and determine their serological status. Blood will be collected at day 1, then 4 to 6 weeks after the bite. For 2 subgroups of participants, selected for their sensitization to a-Gal and a control group without a-Gal sensitization, a 3rd visit is planned 8 to 12 weeks after the bite for clinical assessment. A questionnaire on the 2 first visits will collect data regarding tick bite history, current tick bite, current health status, allergic disease, diet for meat and dairy products.
The tick responsible for the bite will also be collected. The species will be identified and analysed for tick-borne pathogens by PCR. The identification of the tick species and search for tick-borne pathogens will generate crucial data that are important for tick and tick-related disease surveillance in Luxembourg.
20 studies on the registry are indexed under Tick-Borne Diseases; 11 are open to participants now.
Browse Tick-Borne Diseases studies →Luxembourg Institute of Health is the lead sponsor of 28 studies on the registry; 12 are open to participants now.
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Adult population having experienced a recent tick bite and volunteering to visit the study clinic for blood donation at 2 time-points, respectively 3 time-points for a selected subgroup.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Following the second visit 4 to 6 weeks after the tick bite, participants with specific alpha-Gal IgE levels above 0.1 kU/L are assigned to this group of a-Gal sensitized participants.
Following the second visit 4 to 6 weeks after the tick bite, participants with specific alpha-Gal IgE levels below 0.1 kU/L are assigned to this group of a-Gal non-sensitized participants.
Determination of immune signatures leading to allergic sensitization after a tick bite
We expect to determine immune signatures predicting a reaction leading to allergic sensitization and answer fundamental questions on pathways leading from a tick bite to a Th2 immune response.
Time frame: 2 years after the enrollment of the last study participant
Tick and tick-borne pathogen surveillance
The identification of the tick species and search for pathogens will generate crucial data that are important for tick surveillance in Luxembourg
Time frame: From enrollment until 6 months after the last inclusion
Not enrolling at this site.
Plan to share: No
No publications or documents are linked to this record.
Started Jul 2025 (actual). Primary completion is estimated for Feb 2027, 19 months after the start.
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Luxembourg Institute of Health