Biometric and Biological Data for Diagnosis and Therapy of Pain Patients

In order to meet the challenge of an unambiguous diagnosis and effective therapy of SFN or the prognosis of susceptibility to the development of SFN, this project aims to create a data basis on which software will be developed during the project. This software should later be able to combine (integrate) quantifiable biometric data collected from the patient (both objectively measured and patient reported parameters) with the results of biological analyses of the patient's own nerve cells from stem cells. We expect that the patient-specific combination and correlation of biometric and biological data can lead to a significant improvement in the diagnosis, prognosis and therapy of chronic pain. The initial data collection required for the development of such a software (Bio2Integrate) will be carried out in three different project parts: Bio2Watch, Bio2Patient and Bio2Cell

Bio2Watch: In this clinical project part biometric patient data of 24 SFN patients, 3 cancer patients and 21 subjects (control group) will be collected for a period of one year using a PainWatch. The term PainWatch includes an Apple Watch 5 with iPhone 8 and installed app for pain recording. With the aid of the PainWatch, the personal pain sensation in everyday life is documented and personal data such as the pulse rate and the daily number of steps, as well as environmental data, such as the prevailing air pressure, humidity and temperature are recorded. The aim is to use these data as a basis for initial indications of pain-inducing stimuli or combinations of stimuli.

Bio2Patient: In this clinical project part clinically quantifiable tests are carried out, such as quantitative sensory testing (QST), which examines subjective thermal and mechanical sensory perception and pain thresholds. The goal is to determine a specific pain phenotype. In addition, pain evoked potentials (PREPs) are performed to draw conclusions about the function of thin nerve fibers (pain fibers), including projection to the brain. Supplementary SF-36 pain questionnaires are completed to assess the quality of life.For the pain-evoked potentials (PREPs), a total of 20 additional healthy control subjects are to be included (control group D). Four subjects (2 male, 2 female) from each of the age decades 20-29, 30-39, 40-49, 50-59, 60-69 will be included.

Bio2Cell: In the cell-based project part induced pluripotent stem cells (iPS cells) are produced from blood cells of SFN patients, cancer patients and volunteers. These cells will be differentiated into sensory neurons that are relevant in pain processing, so-called nociceptors. Since these nociceptors are derived from the individual patient, they carry the individual genetic characteristics of the patient. These neurons are then analyzed by multi-electrode arrays (MEA). With this method environmental influences such as temperature and air pressure or drugs on the pathophysiology of the patient's are investigated. The main goal is to simulate the conditions, which lead to pain sensation in the context of Bio2Watch and Bio2Patient.

Bio2Integrate: The results from Bio2Watch, Bio2Patient and Bio2Cell will then flow into the software to be developed during the project. Thus, in addition to the identification of stimuli that stimulate pain as well as a genetic correlation to certain markers will be possible. In addition, the targeted modification of the cellular properties of the patient's own sensory neurons through the application of the chemotherapeutic agent can be investigated. To this end, measurements will be made on the cells before and after the application of the substance and compare them with each other. This is the basis for components of the "machine learning " of the Bio2Integrate software.The results of the clinical subprojects are thus an essential component of Bio2Integrate.

Eligibility Criteria:
Inclusion Criteria:

Group A: Criteria 1-5 Group B: Criteria 2-5 Group C: Criteria 2-6 Group D: Criteria 2-4

1. Small fiber neuropathy (after clinical examination or QST or skin biopsy findings)
2. Legal age
3. Written declaration of consent
4. Persons who are legally competent and mentally capable of following the instructions of the staff
5. Sufficient affinity for independent handling of the technology used (PainWatch incl. the corresponding apps) for daily digital pain recording
6. Imminent initiation of neurotoxic chemotherapy in cancer with solid tumors (preferably of the gastrointestinal tract) There are no plans for follow-up recruitment in case no neuropathy develops after chemo.

Exclusion Criteria:

For all Groups:

1. Persons who are accommodated in an institution by order of the authorities or courts
2. Persons who are in a dependent or employment relationship with the auditor
3. For test persons: Exclusion, if they carry a known pain-relevant genetic variant/mutation or suffer from a chronic pain disorder analogous to migraine or chronic back pain.