The relationship between oral mucositis and levels of pro-inflammatory cytokines in serum and in gingival crevicular fluid in allogeneic stem cell recipients.

PURPOSE: Oral mucositis (OM) is a severe side effect of conditioning for allogeneic hematopoietic stem cell transplantation (HSCT). The aim of the present study was to investigate the relationship between oral mucositis and the levels of pro-inflammatory cytokines-both in serum and in gingival crevicular fluid (GCF), in relation to different conditioning regimens.
METHODS: We analyzed the levels of pro-inflammatory cytokines IL-1β, TNF-α, IL-6, and IL-7, as well as anti-inflammatory cytokine IL-10 in gingival crevicular fluid (GCF) and in serum from 43 HSCT patients. Twenty-five received reduced intensity conditioning (RIC) and 18 received myeloablative conditioning (MAC). Cytokine levels were determined in GCF and serum before the start of conditioning, and 1 week and 1 month after HSCT. All patients experienced OM with a median score of 2.1 and median peak on day 11.
RESULTS: There was a significant correlation between OM and MAC (p = 0.035). There were no significant differences in GCF volume at the three time points examined. The levels of IL-6 in GCF increased 1 week after transplantation and then returned to baseline (p < 0.001). The levels of IL-10 in GCF decreased after HSCT (p < 0.001) and remained unchanged. The levels of IL-6 in serum significantly (p < 0.001) increased 1 week after HSCT and decreased to baseline levels after 1 month. The levels of IL-10 in serum significantly (p = 0.02) increased 1 month after HSCT.
CONCLUSION: No correlations between cytokine levels in gingival crevicular fluid and oral mucositis were observed. There was a correlation between severity of OM score and increase in IL-6 in serum. No correlations between cytokine levels in gingival crevicular fluid and in serum were observed.