Prior to all study visits, participants are invited to fill out a set of questionnaires on multiple topics, including socio-economic status, quality of life, physical activity, side effects of and adherence to immunosuppressive therapy, and food frequency questionnaires. At the day of the study visit, whole blood, serum, EDTA plasma, citrate plasma, heparin plasma, 24h collection urine, hair, nails and stool are collected from patients, to be stored in the TransplantLines biobank for future analyses. During study visits, included participants perform a series of physical function tests and neurocognitive tests, that provide insight into the functioning of patients, but also on the side-effects of immunosuppressive drugs, such as polyneuropathy and tremors.
In addition to these samples and tests, tissue samples including e.g. samples of skin, adipose tissue, ureter, arteries, veins, trachea, explanted livers and lungs are collected at the time of transplantation, depending on the type of transplantation. Samples are also collected at times of kidney biopsies in kidney transplant recipients, at times of protocol biopsies and at times of suspected rejection.