Pos1443 correlation between saxon test and unstimulated salivary flow rate in patients with suspected sjögren´s syndrome

Background Sjögren syndrome (SS) is a chronic systemic autoimmune disease characterized by lymphocytic infiltration of the exocrine glands, which alters their function producing dryness of the mouth, eyes and other mucous membranes. The method used to quantify glandular hypofunction is by whole saliva flow stimulated and unstimulated (UWSF) [1], which takes between 5 and 15 minutes (min).The Saxon test (St) [2], is another tool with the same objective but requires less time: 2 minutes. In the literature, we only have found one study that compared the Saxon test with other diagnostic methods although it is developed in patients without SS [3]. Objectives To compare the Saxon test and UWSF in a cohort of patients with suspected SS. Methods In a consecutive cohort of patients who attended the rheumatology department for suspected SS, UWSF was measured (mL/5 min) and the Saxon test (gr/2 min) was performed. The Index Reported by Patients with SS of the EULAR (ESSPRI) was collected too. This is a patient-reported index designed to assess the severity of patients’ symptoms (dryness, pain, somatic and mental fatigue) in SS through an average of single 0–10 numerical scale for each domain. To measure the UWSF, patients were asked to swallow their saliva before the start of the test and then to spit into a container for 5 min. The St was performed by calculating the difference in the weight of two pieces of sterile gauze that the patient chews for two minutes. A UWSF >0.25 mL/min and a St >2.75 g/2min were considered normal, as well as and ESSPRI<5. Spearman’s rank correlation coefficient (rs) was used to determine the correlation between both quantitative variables. The Chisquare test and the Gamma test were used in the comparisons between the groups (altered and normal) and the Mann-Whitney U in the comparisons of the quantitative variables based on the groups (altered and normal) previously defined. P values <0.05 were considered statistically significant. Results We enrolled 199 patients (166 women), with a mean age ± standard deviation of 55,1±13,7 years. The medians (Me) and interquartile ranges (IQR) obtained were 1,50 (0.70 – 2.50) mL/5min for the UWSF, 2,31 (1,60-3,10) g/2min for the St, 6,33 (3.67- 7.67) for ESSPRI and 7,00 (5,00-8,00) for ESSPRI-dryness score. A direct and significant correlation between the St and the UWSF (rs=0,391; P=2,236x10 -7 ) was observed; 76 patients (38,2 %) presented an altered UWSF and 107 patients (65,2 %) had an altered St. When we analysed the intensity of the association between the different groups (altered/normal) of both variables, we observed a direct and significant association (Gamma value=0,4, P =0,019) between both tools. We also detected differences in the St between patients with altered UWSF (Me: 1,72gr/2min; IQR: 1,04-2,50) and those with normal UWSF (Me: 2,62 gr/2 min.; IQR: 1,95-3, 54) ( P =3,9x10 -6 ). Similarly, we observed significant differences in UWSF values between patients with altered St (Me: 1,50 mL/5min IQR: 0,60-2,50) and those with a normal St (Me: 2,00 mL/5min IQR: 1,00-3,00) ( P =0,014). Regarding the ESSPRI, 129 (65,8 %) patients presented an altered ESSPRI and 153 (78,1%) had an altered ESSPRI-dryness score. The group patients with ESSPRI-dryness score≥5 obtained significantly lower scores on the St (Me: 2,10 g/2min IQR: 1,39-3.01), on the UWSF (Me: 1,5 ml/5min IQR: 0,6-2,0), and on the ESSPRI (Me:7,00 IQR:5,33-8,00) than the normal ESSPRI-dryness score group: Me:2,98 g/2min, IQR:2,22-3,75, on St ( P =0,001); Me:2,45 ml/5min, IQR:1,50-3,50, on UWSF ( P =6,547x10 -5 ); Me: 3,17 IQR:1, 00-4.08, on the ESSPRI ( P =1,17x10 -15 ). Conclusion In patients with suspected SS, there is a direct and significant correlation between the St and the UWSF. Therefore, the St could be useful in the initial assessment of oral gland dysfunction, to save time and/or to select patients who require performing the UWSF. References [1]Martínez Ceballos MA et al. Rev. Colomb Reumatol.2020; 27 (S2):90-101. [2]Kohler PF & Winter ME. Arthr & Rheum. 1985;28(10):1128-32. [3]Minagi HO et al. J Oral Rehabil.2020;47:1550-6. Acknowledgements We would like to acknowledge all the patients who have participated in the study. Disclosure of Interests None Declared.