Multicenter lupus register from Argentina, the RELESSAR database: Influence of ethnicity on disease phenotype
Authors: García Mercedes A , Alba Paula , del Campo-Perez Victor , Roverano Susana , Quintana Rosana M , Alvarez Analia P , Graf Cesar E , Pisoni Cecilia , Spindler Alberto , Gomez Catalina , Figueredo Heber M , Papasidero Silvia , Paniego Raul , de la Vega Maria C , Civit Emma , Gonzalez Lucero Luciana , Martire Maria V , Aguila Maldonado Rodrigo , Gordon Sergio , Gobbi Carla , Micelli Marina , Nieto Romina , Rausch Gretel , Gongora Vanina , Damico Agustina , Dubinsky Diana , Orden Alberto , Zacariaz Johana , Romero Julia , Pera Mariana , Goñi Mario , Rillo Oscar , Baez Roberto , Arturi Valeria , Gonzalez Andrea , Vivero Florencia , Bedoya Maria E , Shmid Maria M , Caputo Victor , Larroude Maria S , Dominguez Nadia , Gómez Graciela N , Rodriguez Graciela N , Marin Josefina , Collado Victoria , Jorfen Marisa , Bedran Zaida , Curti Ana , Gazzoni Maria V , Sarano Judith , Zelaya Marcos , Sacnun Monica , Finucci Curi Pablo , Rojas Tessel Romina , Arias Saavedra Maira , Sattler Maria E , Machado Escobar Maximiliano A , Astesana Pablo , Paris Ursula , Virasoro Belen Maria , Santa Cruz Maria J , Allievi Alberto , Vandale Juan M , Hojberg Noelia G , Pons-Estel Bernardo 
Published: April 2022

Objective The objective is to describe the main characteristics of patients with systemic lupus erythematosus (SLE) in Argentina and to examine the influence of ethnicity on the expression of the disease. Patients and methods RELESSAR is a multicentre register carried out by 106 researchers from 67 rheumatologic Argentine centres. It is a cross-sectional study of SLE (1982/1997 ACR) patients. RELESSAR electronic database includes demographic, cumulative SLE manifestations, SELENA-SLEDAI, SLICC-SDI, Katz’s severity and Charlson’s comorbidity indexes and treatment patterns. Results We included 1,610 patients, 91.7% were female with a median age at diagnosis of 28.1 ± 12.8; 96.2% met ≥4 ACR 1982/97 criteria. Frequent manifestations were arthritis (83.5%), malar rash (79.5%), photosensitivity (75.3%), haematological (63.8%) and renal disease (47.4%), antinuclear antibodies (96%), anti-dsDNA (66.5%) and anti-Smith antibodies (29%). The mean Selena-SLEDAI score at last visit was 3.18 (SD 4.3) and mean SDI was 1 (SD 1.3). The accumulated treatments most frequently used were antimalarials (90.4%), corticosteroids (90%), azathioprine (31.8%), intravenous cyclophosphamide (30.2%), mycophenolate mofetil or mycophenolic acid (24.5%), methotrexate (19.3%), belimumab 5.3% and rituximab 5.1%. Refractory lupus was diagnosed in 9.3% of the cases. The main causes of death were lupus activity (25.0%), activity and concomitant infections (25.0%), infections (18.2%), vascular disease (13.6%) and cancer (4.5%). Mortality was associated with higher SLEDAI, Katz, damage indexes and comorbidities. Of the 1610 patients included, 44.6% were Caucasian, 44.5% Mestizo, 8.1% Amerindian and 1.2% Afro-Latin American. Mestizo patients had higher male representation, low socioeconomic status, more inadequate medical coverage, fewer formal years of education and shorter disease duration. Polyadenopathies and Raynaud’s phenomenon were more frequent in Caucasians. In the logistic regression analysis higher damage index (OR 1.28, CI 95% 1.02–1.61, p = 0.03) remained associated to mestizo ethnicity. Conclusions This study represents the largest number of adult patients with SLE studied in Argentina. Caucasian patients were differentiated by having Raynaud’s phenomenon and polyadenopathy more frequently, while patients of Mestizo origin had higher damage indexes.