Ioanna Aritzi

Introduction The complex nature of xerostomia prevents the establishment of a definite cure. Recently, research has pivoted towards stem cell transplantation for glandular reconstruction. The aim of this study is to provide an updated review of the existing research, to highlight the encountered challenges and research pathways, potentially enhancing the therapeutic applications of stem cell transplantation. Methods This is a systematic review according to PRISMA guidelines, using the following databases: PubMed (PMC), PMC Europe, Scopus, Medline, Research Gate, Elsevier. The main question was whether stem cell therapies can contribute to the treatment of xerostomia. Results 19 of 226 publications met the criteria for this review, including ‘in vivo’, ‘in vitro’ studies and clinical trials. All 19 studies described thoroughly the stem cell source and the transplantation method, and documented results based on analytical and statistical methods of confirmation. Data show that the various sources of stem cells play a significant role, with bone marrow or adipose tissue-derived pluripotent blasts being the most utilized. Human transplants in mice have also been accepted and reversed hyposalivation. The effects have been beneficial especially in models undergone radiotherapy (IR) or exhibit Sjogren Syndrome-like symptoms (SS), suggesting that with appropriate treatment and enrichment techniques, stem cell transplantation seems effective regardless of the cause of the disorder. Extracts and co-cultures of gland and stem cells also seem to improve gland function. Conclusion Although in its initial stages, the use of stem cells seems to be a promising therapy to alleviate xerostomia regardless of its cause.

Rheumatoid arthritis (RA) is a systemic autoimmune disease affecting up to 1% of the worldwide population. RA is associated with multiple extra-articular manifestations (EAMs). Middle ear, cochlea and the auditory nerve are suspected sites of RA activity and hearing loss is a possible novel EAM of RA. Objective was to investigate the association of RA with the different subtypes of hearing loss. This systematic review was performed according to the PRISMA guidelines. A random effects model meta-analysis was conducted and the I² was used to assess heterogeneity. Twelve studies comprising 20,022 RA patients and 79,244 controls were included in this systematic review. All studies were observational and were rated to a moderate rate of bias. RA patients had nearly fourfold increased odds of sensorineural hearing loss (SNHL) compared with controls (OR 3.42; 95% CI 2.50–4.69; I² = 13). RA patients also had a significantly increased risk of SNHL (RR 2.28; 95% CI 1.88–2.76; I² = 0). RA patients did not have increased odds of conductive hearing loss (CHL) and mixed hearing loss (MHL) (OR 1.36; 95% CI 0.52–3.55; I² = 22); (OR 2.73; 95% CI 0.78–9.58; I² = 0%). RA is significantly associated with SNHL. RA is not associated with CHL and MHL. Early screening of RA patients with pure tone audiometry should be considered.