Mesenchymal stromal cell therapy for feline chronic gingivostomatitis: Long term experience

Abstract

Introduction: Mesenchymal stromal cells (MSC) therapy has emerged as a potential treatment option for refractory FCGS. However, there is a lack of long-term data on the use of MSC therapy in cats. This study aimed to evaluate the long-term safety and efficacy of MSC therapy for FCGS and investigate potential factors associated with treatment outcomes.

Methods: This study was a retrospective evaluation of 38 client-owned cats with refractory FCGS who received MSC therapy. Medical records, histopathology, and the Stomatitis Activity Disease Index (SDAI) were reviewed. Correlations of the long-term follow-up success rates with SDAI and cell line type used were conducted. A client survey was also performed to assess side effect occurrence, quality-of-life following treatment, and overall treatment satisfaction.

Results: Long-term follow-up ranged from 2 to 9 years post-MSC treatment. The overall positive response rate to MSC treatment was 65.5%, with 58.6% of cats exhibiting permanent improvement or cure. Adverse effects occurring during or immediately after treatment were noted in 34.2% of cases, the majority being transient, self-resolving transfusion-like reactions. No long-term adverse events were noted. No significant correlation in outcome was detected between allogeneic and autologous MSC treatment (p = 0.871) or the severity of the SDAI at entry (p = 0.848) or exit (p = 0.166), or the delta SDAI between entry and exit (p = 0.178). The status 6 months (none to partial improvement vs. substantial improvement to resolution) post-therapy was a predictor of long-term response (value of p < 0.041). Most clients were satisfied with the treatment and outcomes, with 90.6% willing to pursue treatment again, given a similar situation.

Discussion: The results of this study support the use of both autologous and allogeneic MSC as an efficacious and safe therapeutic option for refractory FCGS.

Keywords: MSC; cats; dentistry; gingivostomatitis; regenerative medicine; stromal cells.

Figure 1

Distribution of severity levels before and after MSC treatment, subjectively scored by owners through the distributed survey. See Supplementary material questions 3–4 for the severity scoring prompt.

Figure 2

Long-term clinical follow up to measure disease severity. (A) Images obtained in original studies (Pre-MSC, 6 month follow-up) for three cases (complete response, partial response, and no response). (B,C) Stomatitis disease index (SDAI) of all patients having received allogeneic and autologous adMSC for all time points available (Pre-MSC, 6 months, 18 months, 2022-recheck). (D) Owner ranked severity level (1–10) compared with veterinarian-generated SDAI score (0–30; Supplementary material). SDAI scores were formed using a 0–3 scoring scale for ulceration, erythema, and/or proliferation of seven oral areas (maxillary attached gingiva, maxillary buccal mucosa, mandibular attached gingiva, mandibular buccal mucosa, palatoglossal arch, sublingual, molar gland), with an owner subjective ranking and weight change score added thereafter, also using a 0–3 scale.