SAT0377 ASSESSMENT OF ANKYLOSING SPONDYLITIS ACTIVITY DURING PREGNANCY USING DIFFERENT ACTIVITY INDICES
Authors: O. Krichevskaya, Z. Gandaloeva, T. Dubinina, A. Demina
Journal: Annals of the Rheumatic Diseases (2020)

Background: Currently, there is no consensus on the effect of pregnancy on the activity of ankylosing spondylitis (AS). Moreover, in the absence of a pregnancy modified AS activity index, it remains unclear which of the commonly accepted tools can most adequately assesses AS activity during gestation. Objectives: To assess the dynamics of AS activity during pregnancy, using Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) и Ankylosing Spondylitis Disease Activity Score CRP (ASDAS- CRP). Methods: The study group included 36 pregnant women with confirmed AS (modified New York criteria, 1984). Patients’ mean age was 31.6±4.8 years, mean age at AS onset was 21.8±10.9, and disease duration - 134.9±89.3 months. Activity was assessed using BASDAI and ASDAS-CRP at 10-11, 20-21, and 31-32 weeks of pregnancy. BASDAI at the time of conception was assessed retrospectively at the first visit. Results: BASDAI values in the month of conception and in the trimesters of pregnancy were 2.3 ±1.9; 2.8 ±1.72 ( p &lt;0.05 compared to the month of conception); 3.2 ±1.9 and 3.3 ±2.1. Analyzed dynamics of individual BASDAI components is indicative of increasing fatigue from the month of conception (2 [1; 3,5]) and up to 10-11 weeks of pregnancy (5 [3; 7]; p &lt;0.05); the statistical differences with month of conception remained in the II and III trimesters. In the II trimester a tendency to growing back pain (3 [2; 4]) and entheses pain (2 [0; 4]) as compared to the month of conception (2.5 [1; 4] and 1 [0; 2], respectively) was documented. There was an increase in the intensity and duration of morning stiffness in the III trimester (3.5 [1; 7] and 2.5 [1; 5], respectively) compared to the month of conception (1.5[0; 4] and (2 [0; 3], respectively; p &lt;0.05). ASDAS-CRP values by trimesters of pregnancy were as follows: 1.9 ±0.7; 2.3 ±0.9 and 2.2 ±0.8. There was a tendency to increasing CRP levels in the II (8.0 [2.1;9.6] mg/l) and III trimesters (7.9 [2.0;9.2] mg / l) compared to the I trimester (5.7 [1.6;6.2] mg/l). Patients’ distribution by grades of AS activity is presented in the Table. Disease activity BASDAI ASDAS – CRP month of conception trimester 1 trimester 2 trimester 3 trimester 1 trimester 2 trimester 3 inactive/low 57,8% 33,3% 25,7% 35,3% 16,7% 14,3% 14,7% mild 30,6% 36,1% 40% 26,5% 42,2% 28,6% 32,4% high 11,1% 30,6% 31,4% 31,4% 33,3% 48,6% 41,2% very high 5,6% 0 2,9% 2,9% 2,8% 8,9% 11,8% When dividing patients into two groups depending on AS activity in the I trimester (group 1-low activity, group 2-moderate, high and very high activity), no significant change in the values of both BASDAI and ASDAS – CRP was identified in each group during pregnancy. Conclusion: A tendency of increasing AS activity during the first half of pregnancy with no reverse until the end of gestation based on BASDAI and ASDAS – CRP values and CRP levels was found. There was a discrepancy in degree of activity assessed by the tools used: moderate and high disease activity was identified in greater number of AS patients based on ASDAS-CRP scores compared to BASDAI during the entire pregnancy. It is deemed necessary to continue research so that to identify the most adequate index for AS activity assessment during pregnancy. Disclosure of Interests: Olga Krichevskaya: None declared, Zuleykhan Gandaloeva: None declared, Tatiana Dubinina Speakers bureau: Novartis, BIOCAD, MSD, Pfaizer, Abbvie, UCB, Anastasiya Demina: None declared