Salivary Osteopontin as a Potential Biomarker for Oral Mucositis

Osteopontin (OPN), a multifunctional phosphoglycoprotein also presents in saliva, plays a crucial role in tumour progression, inflammation and mucosal protection. Mucosal barrier injury due to high-dose conditioning regimen administered during autologous and allogeneic peripheral stem cell transplantation (APSCT) has neither efficient therapy nor established biomarkers. Our aim was to assess the biomarker role of OPN during APSCT, with primary focus on oral mucositis (OM). Serum and salivary OPN levels were determined by ELISA in 10 patients during APSCT at four stages of transplantation (day −3/−7, 0, +7, +14), and in 23 respective healthy controls. Results: There was a negative correlation between both salivary and serum OPN levels and grade of OM severity during APSCT (r = −0.791, p = 0.019; r = −0.973, p = 0.001). Salivary OPN increased at days +7 (p = 0.011) and +14 (p = 0.034) compared to controls. Among patients, it was higher at day +14 compared to the time of admission (day −3/−7) (p = 0.039) and transplantation (day 0) (p = 0.011). Serum OPN remained elevated at all four stages of transplantation compared to controls (p = 0.013, p = 0.02, p = 0.011, p = 0.028). During APSCT elevated salivary OPN is a potential non-invasive biomarker of oral mucositis whereas the importance of high serum OPN warrants further studies.

Female sex as an independent prognostic factor in the development of oral mucositis during autologous peripheral stem cell transplantation

Oral mucositis (OM) is a frequent complication of stem cell transplantation-associated toxicity in haematological malignancies, contributing to mortality. Therapy still remains mainly supportive. We assessed risk factors in retrospective analysis of 192 autologous peripheral stem cell transplantation patients with lymphoma and multiple myeloma (MM), respectively. Futhermore, we examined the hormone levels both in serum and saliva during transplantation in 7 postmenopausal female patients with lymphoma compared to healthy controls using electrochemiluminescence immunoassay (ECLIA). Multivariable analysis revealed neutrophil engraftment (p < 0.001; p = 0.021) and female sex (p = 0.023; p = 0.038) as independent predictive factors in the combined patient group and in the lymphoma group, and neutrophil engraftment (p = 0.008) in the MM group. Of the 85 female participants 19 were pre- and 66 postmenopausal. Fifteen of the pre-, and 49 of the postmenopausal women developed ulcerative mucositis (p = 0.769), more often with lymphoma than MM (p = 0.009). Serum estrogen decreased significantly both in postmenopausal controls and transplantated patients compared to premenopausals, with no difference in saliva. Serum progesterone level was significantly (p = 0.026) elevated at day + 7 of transplantation, while salivary progesterone increased at day + 7 and + 14. Our results indicate a predominantly negative effect of female sex hormones on oral immunity with role in the aetiopathogenesis of OM.