Allogeneic UCMSC treatment improves salivary gland function and suppresses disease activity and autoimmunity in SS patients. (A) SSDAI scores for all 24 patients decreased 2 weeks and 1, 3, 6, and 12 months after UCMSCT (all P < .05). (B) The VAS of all 24 patients decreased significantly after UCMSCT (all P < .05). Unstimulated (C) and stimulated (D) salivary flow rate of the 11 patients with xerostomia increased significantly at 2 weeks after UCMSCT (all P < .05) and maintained this level at 1, 3, 6, and 12 months of follow up. (E) The Treatment Emergent Symptom Scale score of the 11 patients with xerostomia decreased 2 weeks after UCMSCT (P = .05) and maintained at this low level on subsequent visits. (F-G) Allogeneic UCMSCT regulated SS-related autoantibodies in serum. (F) Anti-SSA/Ro decreased from 84.76 ± 62.19 U/mL at baseline to 0.51 ± 0.22 U/mL 1 month after treatment (n = 7), and (G) anti-SSB/La decreased from 146.62 ± 83.08 U/mL to 52.61 ± 38.67 U/mL (n = 6) 1 month after treatment.