Treatment of xerostomia with mesenchymal stem cells – a systematic review and meta-analysis of clinical trials

Background Salivary hypofunction and xerostomia are major complications for overall quality of life. Two of the most frequent causes of xerostomia are radiotherapy of the head and neck and Sjögren’s disease. An increasing number of clinical human studies suggest that mesenchymal stem cell (MSC) therapy can ameliorate symptoms of xerostomia. However, a meta-analysis is yet to summarize the results. The primary outcome of this study was unstimulated salivary flow rate (UWS) after treatment with MSCs. Methods The MEDLINE, EMBASE, and Cochrane databases were searched for eligible studies. Eligible studies were: clinical studies including patients with salivary hypofunction due to either radiotherapy or Sjogren’s disease who were subsequently treated with MSCs. A meta-analysis was conducted for the included randomized controlled trials. Secondary outcomes include method of administration, number of MSC used, change in patient reported outcomes, development of drug-specific antibodies, and safety Results Eight studies were included describing 5 clinical trials. 230 participants were treated, hereof 126 received MSC treatment. In the meta-analysis, an increase in UWS of 0.06 mL/min (95%CI: -0.05 to 0.17) were found. In a subgroup analysis of radiation induced xerostomia, a significant increase in UWS of 0.03 mL/min (95%CI: 0.01–0.05) were found. All trials reported improvement in patient reported outcomes. Further, no treatment-related serious adverse events were reported, and few, minor, and temporary adverse events was observed. Conclusion MSC treatment for xerostomia holds promise as a future treatment. Further, MSC treatment was found to be safe with minor, temporary adverse events.