Peripheral-Blood IL-1β/TNF-α and Candidate microRNA Trajectories After Intra-Articular Orthokine, Platelet-Rich Plasma, or Hyaluronic Acid for Sacroiliac Joint Osteoarthritis: A Prospective Non-Randomized Cohort Study

Background:The sacroiliac joint (SIJ) is a common source of chronic low back pain.This study aimed to compare wholeblood IL1B/TNF transcripts, 6 candidate microRNAs, plasma interleukin-1b (IL-1b), and tumor necrosis factor-a (TNF-a) between patients with SIJ osteoarthritis (OA) and a reference group, and to describe their trajectories after intra-articular therapy. Material/Methods:In a prospective, single-center, non-randomized cohort, 90 patients with SIJ OA received autologous conditioned serum (Orthokine), platelet-rich plasma (PRP), or hyaluronic acid (HA) (n = 30 each).Thirty disease-free volunteers formed the reference group.No placebo or sham group was included.Molecular markers and pain, disability, and quality-of-life scores were assessed before treatment and at 7, 28, 90, and 180 days after the last injection, using mixed-effects models and repeated-measures correlation with false-discovery-rate correction. Results:After adjustment for age, body mass index, C-reactive protein, and sex, SIJ OA was associated with higher TNF/IL1B transcript and protein levels and altered expression of all 6 microRNAs.Clinical and cytokine trajectories differed by treatment (time × treatment P  0.002), and mean pain and disability improvements met minimal-important-change thresholds with Orthokine and PRP but not HA.hsa-miR-155-5p and hsa-miR-181c-5p were nominally associated with TNF-a protein after adjustment for visit and treatment, but no association survived second-stage multiplicity correction.Conclusions: SIJ OA was associated with a distinct peripheral-blood cytokine and microRNA profile, although residual confounding cannot be excluded.Because allocation was non-randomized and no placebo group was included, treatment-related differences are descriptive, and the microRNA associations are hypothesis-generating.