RESUMEN
This study is primarily aimed at assessing serum changes on a large panel of proteins in patients with chronic back pain following spa therapy, as well as evaluating different spa therapy regimens as a preliminary exploratory clinical study. Sixty-six patients with chronic back pain secondary to osteoarthritis were randomly enrolled and treated with daily mud packs and bicarbonate-alkaline mineral water baths, or a thermal hydrotherapy rehabilitation scheme, the combination of the two regimens or usual medication only (control group), for two weeks. Clinical variables were evaluated at baseline, after 2 and 12 weeks. One thousand serum proteins were tested before and after a two-week mud bath therapy. All spa treatment groups showed clinical benefit as determined by improvements in VAS pain, Roland Morris disability questionnaire and neck disability index at both time points. The following serum proteins were found greatly increased (≥2.5 fold) after spa treatment: inhibin beta A subunit (INHBA), activin A receptor type 2B (ACVR2B), angiopoietin-1 (ANGPT1), beta-2-microglobulin (B2M), growth differentiation factor 10 (GDF10), C-X-C motif chemokine ligand 5 (CXCL5), fibroblast growth factor 2 (FGF2), fibroblast growth factor 12 (FGF12), oxidized low density lipoprotein receptor 1 (OLR1), matrix metallopeptidase 13 (MMP13). Three proteins were found greatly decreased (≤0.65 fold): apolipoprotein C-III (Apoc3), interleukin 23 alpha subunit p19 (IL23A) and syndecan-1 (SDC1). Spa therapy was confirmed as beneficial for chronic back pain and proved to induce changes in proteins involved in functions such as gene expression modulation, differentiation, angiogenesis, tissue repair, acute and chronic inflammatory response.