AB0344 PREVALENCE AND RISK FACTORS FOR SEROSITIS IN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS: A CASE CONTROL STUDY
Authors: L. Gimeno-Torres, I. Carrión Barberà, X. Duran, T. C. Salman Monte
Journal: Annals of the Rheumatic Diseases (2021)

Background: Systemic lupus erythematosus (SLE) is an autoimmune multisystemic disease with a wide variety of clinical manifestations, being one of them serositis, which includes pericarditis, pleuritis and peritonitis [1]. Incidence of serositis ranges between 11-54% [2]. Objectives: To determine the prevalence of serositis in patients (pt) with SLE attended at the outpatient Lupus Unit and identify factors that could be used as predictors of this manifestation. Methods: Retrospective case-control study. 297 medical records of SLE pt were reviewed: 28 pt were diagnosed with serositis (cases) and were age- and sex-matched with 2 controls with SLE without serositis. Differences between cases and controls were analyzed as well as factors associated with serositis. Results: Patient’s characteristics are described in Table 1. The prevalence of serositis in our cohort was 9.42%. The difference between the prevalence of serositis in men and women was statistically higher in men, 30% vs 7.9% (p=0.001, CI 95%: 1.7%-42.4%). Serositis was diagnosed at an age of 41 ±14 years (y) and in 40.7% it was the first symptom. Time from SLE diagnosis to serositis was 4±5.3 y. 10 pt had recurrences: 6 had 2, and 4 had 3. Incidence of pericarditis and pleuritis was 78.6% and 82.1% respectively. 2 pt suffered from pericardial tamponade. Mean prednisone dose received during the serositis was 44.6±26.6mg. At the moment of serositis 100% were ANA+, 85.7% antidsDNA+, 80% CrithidiaDNA+, 57.9% antiRo60+, 52.6% antiRo52+, 15.9% antiLa+, 47.4% antiRNP+, 21.1% antiSm+, and 77.8% had low C3. When looking for serositis-associated factors we only found association with antidsDNA measured by Crithidia (p=0.016) and different measures of glucocorticosteroids (GC), having cases needed higher doses than controls (Table 1). Those with serositis had significantly received more mycophenolic acid (p=0.021) and marginally, more belimumab (p=0.056). Table 1. Comparison between groups of adverse maternal-fetal outcome. VARIABLES CASES (28) CONTROLS (54) p-value Female 22 (33.3%) 44 (66.7%) 0.775 Male 6 (37.5%) 10 (62.5%) Caucasian 20 (32.8%) 41 (67.2%) 0.693 Hispanic American 7 (38.9%) 11 (61.1%) Others 1(33.3%) 2 (66.6%) Arthritis 22 (38.6%) 35 (61.4%) 0.219 Leukopenia 17 (34.0%) 33 (66.0%) 1.000 Lymphopenia 25 (33.8%) 49 (66.2%) 1.000 Thrombocytopenia 5 (20.8%) 19 (79.2%) 0.128 Nephritis 8 (50.0%) 8 (50.0%) 0.152 Raynaud’s phenomenon 6 (42.9%) 8 (57.1%) 0.263 Haemolytic anaemia 3 (42.9%) 4 (57.1%) 0.686 Antinuclear antibodies 28 (34.6%) 53 (65.4%) 1.000 AntidsDNA 23 (37.7%) 38 (62.3%) 0.295 AntiSm 9 (42.9%) 12 (57.1%) 0.425 AntiRo52 10 (41.7%) 14 (58.3%) 0.444 AntiRo60 13 (37.1%) 22 (62.9%) 0.645 AntiRNP 14 (43.8%) 18 (56.3%) 0.159 CrithidiaDNA 19 (47.5%) 21 (52.5%) 0.016 Low C3 21 (39.6%) 32 (60.4%) 0.224 Low C4 13 (38.2%) 21 (61.8%) 0.637 Low CH50 13 (39.4%) 20 (60.6%) 0.480 SLICC* 0.54 (±0.9) 0.49 (±1.1) 0.717 SLEDAI* 3.1 (±3.1) 2.98 (±3.2) 0.844 Corticosteroids Ever 27 (38.6%) 43 (61.4%) 0,051 Pulses ever 9 (60.0%) 6 (40.0%) 0.033 Maximum prednisone dose ever: &lt;10mg 18 (85.7%) 3 (14.3%) 0.003 10-29mg 14 (87.5%) 2 (12.5%) 30-60mg 11 (45.8%) 13 (54.2%) &gt;60mg 8 (47.1%) 9 (52.9%) Conclusion: The prevalence of serositis was 9.42%. Serositis is significantly more frequent in SLE men than in women: almost ⅓ will develop serositis, so we need greater awareness of serositis in SLE men. CrithidiaDNA+ was identified as an associated factor of serositis. Furthermore, pt with serositis significantly received more pulses of GC and a higher maximum dose throughout the disease, which could imply a more aggressive form of SLE than in those without serositis. No correlation was found between serositis and any other characteristic. References: [1]Hochberg MC. Updating the American College of Rheumatology revised criteria for the classification of systemic lupus erythematosus. Arthritis Rheum 1997;40:1725 [2]Ryu S, Fu W, Petri MA: Associates and predictors of pleurisy or pericarditis in SLE. Lupus. Science. 2017, 4(1):e000221. Disclosure of Interests: None declared