The goal of this observational study is to understand the immune response in Fabry disease (FD). We want to find out how the immune response is related to the severity of FD and how it affects patients' quality of life and pain.

Main Questions the Study Aims to Answer:

• How are immune response markers linked to the health of FD patients?
• How is the immune response different between FD patients and healthy individuals?

Participants:

We will include 20 patients who have FD and are older than 18, and do not have other autoimmune or autoinflammatory diseases. We'll also include a comparison group of the same size who don't have FD, but are similar in age and sex to the FD group.

Participants with Fabry disease will be asked about their medical history and complete questionnaires. We will measure their vital signs and collect blood samples to study immune response markers. We'll also look at specific biomarkers related to FD.

Healthy participants will do similar tasks for comparison.

Comparison: Researchers will compare the immune response markers and other measurements between FD patients and healthy individuals to understand the differences and similarities.

Duration: The study will take place over 18 months to gather comprehensive information.

Rationale: The immune response could play a relevant role in the pathophysiological mechanisms of Fabry disease (FD), although the relationship between the activated immune pathways and the clinical expression of the disease needs to be clarified. Knowledge of the immune response in FD could help to better understand the progression of the disease, identifying new biomarkers potentially useful in the clinical follow-up of these patients.

Study design: Observational cross-sectional study with a control group. Study subjects: Target group: patients with Fabry disease, older than 18 years and without autoimmune or autoinflammatory diseases. Control group: subjects without Fabry disease matched for age (± 5 years) and sex.

Sample size: n=40 (20 patients with Fabry disease + 20 controls).

Objectives:

1. To study the relationship between immune response biomarkers and the clinical status of the patient, as measured by the MSSI scale (Mainz Severity Score Index) or by markers of target organ damage (clinical, biochemical and imaging parameters).
2. To characterize the immune response profile by circulating biomarkers of subjects with Fabry disease (FD) compared to healthy subjects.
3. To compare circulating biomarker values with those measured in PBMC (Peripheral Blood Mononuclear Cells) culture supernatant from patients with FD.
4. To evaluate the relationship between biomarkers of the immune response and the concentration of specific Fabry disease markers (Lyso-Gb3).
5. To evaluate the association between immune response biomarkers and quality of life and neuropathic pain in FD patients.

Variables: Demographics, vital signs, anthropometric data, FD medical history, questionnaires, clinical biochemical variables, biochemical markers of autoimmunity, specific markers of FD (Lyso-Gb3), immune response markers and markers of target organ damage.

Duration: 18 months

For the Fabry Disease (FD) group:

Inclusion Criteria:

• Age ≥ 18 years.
• Diagnosis of Fabry disease (enzymatic or genetic).
• Having signed the informed consent, after having received all the information concerning the study.

Exclusion Criteria:

• Autoimmune or autoinflammatory disease or patients with transplanted organs (corneal transplant excluded) and under additional immunosuppressive treatment.
• Acute cardiovascular event or major surgery in the 90 days prior to inclusion in the study.
• Serious intercurrent diseases such as HIV, COVID-19, cancer under active treatment, severe anemia, severe hepatic, respiratory or renal failure, or other pathologies that, at the investigator's discretion, could interfere with the objectives of the study.

For the Control group:

• Participants must not meet any of the exclusion criteria applied to the target (FD) population and must sign, prior to inclusion, the informed consent form after having received all the information concerning the study.

Population of consecutive patients with Fabry Disease (FD) under follow-up in the Internal Medicine Department of the Hospital Universitario Ramon y Cajal.

In addition, a Control group of subjects without Fabry disease will be included, among those who come to donate blood at the Hospital Universitario Ramón y Cajal.

Controls will be matched for age (± 5 years) and sex with FD patients.

Deidentified data will be made available for sharing upon reasonable request at the discretion of the Principal Investigator.

Data will be made available one year after publication of the main results, during 5 years.

Data will be available for sharing with investigators seeking to verify analyses or to conduct additional analyses that are appropriate to the nature of these data. Data will be made available for sharing upon request.