Discussion
pSS, itching sensation
ADVERSE EVENTS, PATHOGENESIS, SYSTEMIC LUPUS ERYTHEMATOSUS, OTHER AUTOIMMUNE DISEASE
This is a triple-blinded clinical trial aiming at the effect of ADSCs treatment on pSS patients. In general, the results of our study indicate that ADSCs improved the symptoms in to a certain extend objectively and subjectively. The dysfunction of salivary and lachrymal glands was significantly improved in a short period. The level of immunological and inflammatory indexes was reduced after ADSCs treatment. Previous studies found that transplantation of ADSCs could significantly inhibit autoimmune progression in MRL/lpr mice by injecting with ADSCs via the tail veinAlthough the past few years have led to much greater knowledge of the features of patients with pSS, in contrast with other autoimmune diseases such as systemic lupus erythematosus, there is little diagnostic information on clinical pSSBecause the pathogenesis of pSS is not fully elucidated and has a very heterogeneous course, which made the treatments challenging in the pastRecently, the positive effect of ADSCs therapy has been suggested in autonomous immunity diseasesNotably, the origin of ADSCs contributes to the properties of it, such as downstream application. Thus, a standardized protocol for clinical utility will be helpful. A controlled trial by Vangsness et al. introduced a dose of 3 million cells for an individual for an injection to the knee following partial medial meniscectomy and showed an improvement of recoveryAnother finding from our trial is that there were no other adverse events except for two patients with itching sensation in the skin lasting no more than 2 h. A possible reason may be the method used for ADSCs expansion and culture in our study. Unlike in other studies, we used human platelet lysate as the culture media that may have the advantage of diminishing the immune reaction of animal-derived factors. Until recently, fetal bovine serum (FBS) was the supplement of choice for growing MSCs. However, there were some concerns that an immune response could be triggered in the host for FBS as being xenogeneic. Abundant growth factors and cytokines in platelets are vital for the growth of any animal cell including stem cells. Additionally, ADSCs are found in numerous human tissues, which could be accessed and obtained easily on the superficial layers of the skin. These make the ADSCs therapy is a promising method in pSS.Many studies have been conducted to explore the unclear pathogenesis of pSS. Various cells and cytokines such as B cells and T cells are involved in pSSIn order to evaluate the efficacy more comprehensively, we chose both ESSDAI and ESSDAI as the index of subjective symptoms and systemic characteristics that showing to be valid and sensitive measuresA strength of this trial is the use of very strict inclusion criteria and defining activity levels that are crucial for clinical trial design in pSS. The availability of repeated clinical and laboratory assessment over a long follow-up period made it possible to detect the changes of the treatment outcome.However, there are some limitations to the present trial that need to be addressed. The sample size limited the precision of detection some potential significant differences that we hypothesized to detect prior to the trial. Moreover, further analysis of the ADSCs could be conducted such as assessing the immunomodulatory properties, examining whether cells are present at the injection site and monitoring changes in growth factors or cytokines secreted by MSCs. Further limitation is that the dosage and interval of ADSCs administration have not been thoroughly compared.