CORRELATION BETWEEN SAXON TEST AND UNSTIMULATED SALIVARY FLOW RATE IN PATIENTS WITH SUSPECTED SJOGRENS SYNDROME

BackgroundSjögren 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 [2], is another tool with the same objective but requires less time: 2 minutes. In the literature, we only have found one study that compares the Saxon test with other diagnostic methods although it is developed in patients without SS [3].ObjectivesTo compare the Saxon test and UWSF in a cohort of patients with suspected SS.MethodsIn 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 Sjögren’s Syndrome 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 Saxon test was performed by calculating the difference in the weight of two pieces of sterile gauze that the patient chews for two minutes. An UWSF >0.25 mL/min, a Saxon test >2.75 g/2min and an ESSPRI<5 were considered normal. Spearman’s rank correlation coefficient (rs) was used to determine the correlation between both quantitative variables. The Chi-square 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.ResultsWe enrolled 70 patients (63 women/7 men), with a mean age ± standard deviation of 54±13 years. The medians (Me) and interquartile ranges (IQR) obtained were 1.500 (0.6750 – 2.5000) mL/5min for the UWSF, 2.405 (1.6775-3.4925) g/2min for the Saxon test, 6.67 (3.67-7.67) for ESSPRI and 7.00 (4.00-8.00) for ESSPRI-dryness score.A direct and significant correlation between the Saxon test and the UWSF (rs=0.325; P=0.006) was observed. Twenty-four patients (34.3%) presented an altered UWSF and forty-two patients (60%) had an altered Saxon test. 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=0.583, P=0.010) between both tools.We also detected differences in the Saxon test between patients with altered UWSF (Me: 1.89 gr/2min.; IQR: 1.47-2.68) and those with normal UWSF (Me: 2.78 gr/2 min.; IQR: 1.77-3, 75) (P=0.029). Similarly, we observed significant differences in UWSF values between patients with altered Saxon test (Me: 1.30 mL/5min IQR: 0.50-2.13) and those with a normal Saxon test (Me: 2.00 mL/5min IQR: 1.5-2.88) (P=0.008).Regarding the ESSPRI, 42 (62,7%) patients presented an altered ESSPRI and 49 (73,1%) had an altered ESSPRI-dryness score. The group patients with ESSPRI-dryness score≥5 obtained significantly worse scores on the Saxon test (Me: 2.10 g/2min IQR: 1.58-3.07) and on the ESSPRI (Me:7.33 IQR:5.83-8.00) than the normal ESSPRI-dryness score group: Me:3.02 g/2min, IQR:2.20-3.84, on Saxon test (P=0.026); Me: 2.66 IQR:1, 00-4.08, on the ESSPRI (P=0.000).ConclusionIn patients with suspected SS, there is a direct and significant correlation between the Saxon test and the UWSF. Therefore, the Saxon test 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.Disclosure of InterestsNone declared