SAT0603 SENSITIVITY TO PHENYLTHIOCARBAMIDE IN RHEUMATOID ARTHRITIS PATIENTS
Authors: Natalia Dostanko, Viktor Yagur, Tatiana Zybalova, Valery Apanasovich, Viktoria Dostanko
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background:</h3> Sensitivity to phenylthiocarbamide (PTC) as the ability to taste this bitter compound is a genetic marker ranked alongside eye color and blood groups [1,2]. Almost 90 years have passed since the first publication of A.L. Fox on the relationship of the "chemical constitution" and sensitivity to PTC [3] and 35 years later J. Stepan et al. (1965) analyzed the sensitivity to PTK in patients with joint diseases. According to the literature [4,5] sensitivity to PTK is associated with the peculiarities of clinical manifestation and the course of these diseases. <h3>Objectives:</h3> To estimate the sensitivity to PTC in RA patients and its influence on the prognosis of the disease. <h3>Methods:</h3> The physiological parameter of sensitivity to PTC was determined by H. Harris et al. [6]. The total number of dilution thresholds was 15 (PTC<sub>0-14</sub>). Patients were considered as non-tasters (not able to taste PTC) in the case of PTC<sub>0-4</sub> sensitivity thresholds and as tasters in the case of PTC<sub>5-14</sub> sensitivity thresholds. Sensitivity to PTC was assessed in 140 RA patients, 110 women and 30 men, at Minsk clinical hospital №9 and we used the data on the PTC sensitivity of the mixed population of Minsk as a control [7]. <h3>Results:</h3> The frequencies of tasters (PTC+) and non-tasters (PTC-), as well as allele frequencies (T and t) of the PTC sensitivity gene among RA patients and controls are presented in the table. There were no significant differences between general groups of PTC tasters and non-tasters among RA patients and the controls (two-way Fisher exact test, two-way FET, p&gt; 0.1) while the sensitivity threshold of PTC<sub>0</sub> was revealed 2 times less in RA patients than in the control group - 10.7% and 22.1%, respectively (two-way FET, p=0,0057). Operating characteristics of PTC<sub>0</sub> are the following: OR=0.43 CI<sub>95</sub> 0.23-0.78, LR<sup>+</sup>=0.49 CI<sub>95</sub>0.28-0.81, LR<sup>–</sup>=1.15 CI<sub>95</sub> 1.05-1.23, that means that a taste threshold of PTC<sub>0</sub> decreases the chances of RA by 2.0 times. Seronegative RA was significantly more common in non-tasters vs tasters men (two-way FET, p=0,0236) and significantly more common in non-tasters men vs non-tasters women (two-way FET, p=0,0031). RA patients-tasters (PTC+) had significantly more severe functional disorders (functional class 3) vs non-tasters (PTC-) (two-way FET, p=0,0003) and more advanced stages of RA (3-4 stages by O. Steinbrocker) (two-way FET, p=0,0024) with the same duration of RA. <h3>Conclusion:</h3> The taste threshold of PTC<sub>0</sub> decreased the chances of RA by 2.0 times and non-sensitivity to PTC was associated with seronegative RA, especially in men, and more benign course of the disease. <h3>References</h3> [1] Bartoshuk L.M.//Chem. Senses. 2000; 25: 447-460. [2] Guo S.-W., Reed D. R. Ann. Hum. Biol. 2001; 28(2): 111–142. [3] Fox A.L.//Science News Letter. 1931; 9: 249. [4] Stepan J. et al.//Acta Rheumatol. Scand. 1965; 11(4): 258-265. [5] Ondrasík M. et al.//Fysiatr. Revmatol. Vestn. 1972; 50(4): 183-191. [6] Harris H., Kalmus H.//Ann. Eugen. Lond. 1949; 15(1): 24-31. [7] Salivon I.I. et al. (1976): Essays on Anthropology of Belarus. Science and technic, Minsk; 272p. <h3>Disclosure of Interests:</h3> None declared