Human T-cell lymphotropic virus type 1 (HTLV-1) causes chronic infection associated with adult T-cell leukemia/lymphoma (ATLL) and HTLV-1- associated myelopathy/tropical spastic paraparesis (HAM/TSP). In Brazil, the scarcity of biobanks with well-characterized samples limits studies on metabolic biomarkers and therapies.

This study delineates the design, methodology, and operational protocols implemented to establish a biobank dedicated to HTLV-1 samples at the University Municipal of São Caetano do Sul in collaboration with the University of Bristol, enabling research into the impact of metabolomic and environmental factors on disease progression and facilitating the identification of actionable metabolic targets and the evaluation of ex vivo therapeutic interventions to enhance the clinical management of HTLV-1-associated diseases.

Blood was collected from all recruited subjects, processed to isolate plasma and peripheral blood mononuclear cells (PBMCs), aliquoted and immediately frozen at -80 °C in the Biobank of the University Municipal of São Caetano do Sul. A small aliquot of each sample was used for immediate hematological analyses, to ensure data collection for tests is feasible post-freezing. Each biological sample was coded, assigned a Standard PREanalytical Code, and registered in the Monday® software containing all the donor's anamnestic data. All samples were stored under continuous real-time temperature recording using a freezer connected to an alarm system. In addition, a radiofrequency identification tracking system strictly monitored each cryopreservation operation performed throughout the sample lifecycle.

Biological samples were collected from 31 individuals infected with HTLV-1: 6 asymptomatic, 9 ATLL, and 13 HAM-TSP, and 3 healthy participants (control group) from February to July 2025. Different samples were available for research purposes, plasma and frozen peripheral blood mononuclear cells. The quality of the cells obtained through specific standard operating procedures demonstrated that these samples were appropriate for clinical and basic research.

These preliminary results demonstrated the capacity to establish a biobank of HTLV-1 samples for future studies, collecting biological samples and clinical data from individuals with HTLV-1, including ATLL and HAM-TSP, thereby fostering collaboration between research groups in an open and transparent manner. Sharing expertise and resources among scientists will facilitate the transfer of knowledge to clinical practice, preventing disease progression to severe pathologies and enabling the development of more effective therapeutic interventions to improve outcomes and quality of life for patients with HTLV-1. Conflict of Interest: The authors declare no conflict of interest. Financial Support: This study was supported by the Royal Society.