POS0766 CLUSTER ANALYSIS AND COMPARISON OF CUMULATIVE DAMAGE BY DIAPS IN A SINGLE CENTER COHORT OF APS PATIENTS
Authors: O. Uludag, E. Gurel, C. Cetin, E. Cene, Y. Yalçinkaya, A. Gül, M. Inanc, B. Artim-Esen
Journal: Annals of the Rheumatic Diseases (2021)

Background: Antiphospholipid syndrome (APS) is a chronic autoimmune disease with significant morbidity and mortality. The recently developed damage index for APS (DIAPS) considers thrombotic APS specific damage. Objectives: Herein we aimed to identify disease clusters based on clinical characteristics and compare DIAPS between these clusters in a single center cohort of patients with APS ± systemic lupus erythematosus (SLE). Methods: This retrospective study included 237 consecutive patients with APS [114 primary APS (PAPS) and 123 SLE+APS]. Data regarding demographics, clinical and laboratory characteristics and cardiovascular risk factors were retrieved from the existing database and revised. Two-step cluster analysis was performed. Cumulative damage was calculated for all patients by applying DIAPS as described previously. Results: 237 patients were classified into 4 subgroups by cluster analysis. Cluster 1 ( n =74) consisted of older patients with arterial-predominant VT, livedo reticularis and increased cardiovascular risk, cluster 2 ( n =70) of SLE+APS patients with thrombocytopenia and heart valve disease, cluster 3 ( n =59) of patients with venous-predominant VT, less extra-criteria manifestations and cluster 4 ( n =34) of patients with only PM with a lower frequency of extra-criteria features and cardiovascular risk (table 1). Table 1. Demographic, clinical and laboratory characteristics of clusters All ( n =237 ) Cluster 1 ( n =74 ) Cluster 2 ( n =70 ) Cluster 3 ( n =59 ) Cluster 4 ( n =34 ) P Age (years), median (range ) 43 (20-81) 51 (20-81) 40 (27-72) 42 (24-69) 40.5 (26-65) &lt;0.001 Duration of disease (years), median (range ) 9.5 (1-37.7) 13.1 (1-37.7) 10.4 (1-28.7) 8.5 (1-32.8) 7 (1-22.4) 0.028 Female, n (% ) 198 (83.5) 56 (75.7) 61 (87.1) 47 (79.7) 34 (100) &lt;0.05 SLE, n (% ) 123 (51.9) 31 (41.9) 46 (65.7) 32 (54.2) 14 (41.2) &lt;0.05 Vascular thrombosis, n (% ) 191 (80.6) 73 (98.6) 59 (84.3) 59 (100) 0 (0) &lt;0.001 Arterial thrombosis, n (% ) 109 (46) 50 (67.6) 31 (44.3) 28 (47.5) 0 (0) &lt;0.001 Venous thrombosis, n (% ) 112 (47.3) 36 (48.6) 37 (52.9) 39 (66.1) 0 (0) &lt;0.001 Pregnancy morbidity, n (% ) 117 (49.4) 22 (29.7) 46 (65.7) 15 (25.4) 34 (100) &lt;0.001 Livedo reticularis, n (% ) 38 (16) 21 (28.4) 10 (14.3) 5 (8.5) 2 (5.9) &lt;0.01 Thrombocytopenia, n (% ) 81 (34.2) 4 (5.4) 65 (92.9) 4 (6.8) 8 (23.5) &lt;0.001 Heart valve disease, n (% ) 92 (38.8) 32 (43.2) 46 (65.7) 8 (13.6) 6 (17.6) &lt;0.001 Arterial hypertension, n (% ) 101 (42.6) 49 (66.2) 34 (48.6) 18 (30.5) 0 (0) &lt;0.001 Hyperlipidemia, n (% ) 103 (43.5) 69 (93.2) 26 (37.1) 0 (0) 8 (23.5) &lt;0.001 Smoking, n (% ) 58 (24.5) 31 (41.9) 7 (10) 17 (28.8) 3 (8.8) &lt;0.001 Lupus anticoagulant, n (% ) 156 (65.8) 53 (71.6) 48 (68.6) 35 (59.3) 20 (58.8) 0.36 Anticardiolipin IgG/IgM, n (% ) 155 (65.4) 46 (62.2) 46 (65.7) 38 (64.4) 25 (73.5) 0.71 Anti-β2-glycoprotein I IgG/IgM, n (% ) 93 (39.2) 25 (33.8) 33 (47.1) 26 (44.1) 9 (26.5) 0.13 Triple aPL positivity, n (% ) 45 (19) 12 (16.2) 16 (22.9) 13 (22) 4 (11.8) 0.46 Cluster 2 had the highest cumulative damage (mean DIAPS 2.48 ± 1.67) followed by cluster 1 (2.24 ± 1.44), cluster 3 (1.69 ± 1.27) and cluster 4 (0.32 ± 0.68). Comparison of DIAPS (total and major domains) between the clusters is shown in figure 1. Patients with SLE+APS had a higher mean DIAPS compared to those with PAPS (2.10 ± 1.61 vs 1.69 ± 1.47, P =0.046). Cardiovascular domain was the most frequently affected DIAPS domain in both groups. Proteinuria and avascular necrosis were significantly more frequent in SLE+APS (9.8% vs 2.2%, P =0.02 and 5.7% vs 0%, P =0.009, respectively). DIAPS was positively correlated with disease duration (r=0.192, P =0.003). Conclusion: Elder APS patients with arterial thrombosis and increased cardiovascular risk and SLE+APS patients with extra-criteria manifestations had higher cumulative DIAPS. Longer disease duration, higher frequency of major organ involvement and higher immunosuppressive usage may have contributed to this difference. Therefore, control of cardiovascular risk factors, prevention and effective treatment of SLE flares may help to reduce damage in these subgroups. Figure 1. Comparison of mean DIAPS (total and major domains) between the clusters Disclosure of Interests: None declared