An Oral Rinse That Predicts Treatment Outcomes Following Bone-marrow Transplantation

Objective: To determine if a non-invasive oral rinse assay can predict bone marrow engraftment, mucositis resolution and 6 month treatment outcome following hematopoietic stem cell transplantation (HSCT). Methods: Using an oral rinse protocol previously developed by our group, we studied neutrophil tissue delivery kinetics and its relationship to clinical parameters and outcome at 6months post-HSCT in 31 adult patients. Oral neutrophil counts were compared to circulating neutrophil levels, oral mucositis scores and health status at 6 months following HSCT. Results: Neutrophils were detected on average 8.4 ± 3.4 s.d. days earlier in the oral tissues than in the blood circulation, enabling us to confirm successful engraftment more than 1 week earlier than by using blood neutrophil counts alone. As well, we showed that earlier return of neutrophils to the mouth post-HSCT, "oral engraftment" (OE), is a better predictor of oral mucositis symptom resolution than blood engraftment (BE). Furthermore, the time-span between OE and BE may be a successful predictor of treatment outcome at 6 months following HSCT. All 5 patients who showed a short time-span between OE and BE ( ≤5 days) died or relapsed and were therefore categorized as High risk of failure, while patients with a time-span of 6-10 days between OE and BE were considered Moderate risk of failure as 5 out of 15 died or relapsed. A low risk of HSCT failure was considered as ≥11 days where all 9 patients survived without complications. Conclusion: Monitoring the timing of neutrophil recovery to the oral tissues with a non-invasive oral rinse has the potential to allow the physician to identify those patients who are at a high risk of HSCT failure within just a few weeks of their transplantation. Future studies will help determine how better to treat these high and moderate risk patients.