Correlation between salivary epidermal growth factor levels and refractory intraoral manifestations in patients with Sjögren's syndrome

Abstract

Objective. To assess changes in salivary epidermal growth factor (EGF) levels and the correlation between these levels and the severity of intraoral manifestations in Sjögren's syndrome (SS).

Methods. Forty SS patients and 23 controls were enrolled. Salivary EGF concentration was measured using an enzyme-linked immunosorbent assay, and intraoral manifestations were evaluated using a short version of the Oral Health Impact Profile (OHIP-14). The associations among salivary flow rate, EGF levels and the severity of intraoral manifestations were analyzed.

Results. The total salivary EGF output was significantly decreased in the SS patients compared with the controls (9237.6 ± 8447.0 vs. 13296.9 ± 7907.1 pg/10 min, respectively, p = 0.033). In the SS patients, total EGF output and salivary flow rate showed a strong positive correlation (r_s = 0.824, p = 0.0005), while total EGF output and disease duration showed a negative correlation (r_s = −0.484, p = 0.008). Further, total EGF output was significantly correlated with the OHIP-14 score (r_s = −0.721, p = 0.012).

Conclusions. The salivary flow rate and EGF levels are decreased in SS, and this deterioration in saliva quality causes refractory intraoral manifestations. Our findings have provided new therapeutic targets for SS.

Keywords:

• Epidermal growth factor
• Intraoral manifestation
• Oral mucosal involvement
• Saliva
• Sjögren's syndrome

Acknowledgements

We thank Professor Seiichi Hirota (Department of Surgical Pathology, Hyogo College of Medicine) and clinical laboratory technicians (Department of Surgical Pathology, Hyogo College of Medicine Hospital) for assisting with the pathological examinations.

Funding

This work was partly supported by a Grant-in-Aid for Scientific Research from the Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT KAKENHI Grant Number: 22791820) and grants for intractable diseases from the Japanese Ministry of Health, Labor and Welfare.

Conflict of interest

None.