AB0503 CLINICAL AND SEROLOGICAL DIFFERENCES BETWEEN CAUCASIAN AND LATIN AMERICAN SLE PATIENTS IN A MULTIETHNIC SPANISH SINGLE-CENTRE COHORT

Abstract

BackgroundSystemic lupus erythematosus (SLE) is a highly heterogeneous systemic autoimmune disease with multiorgan manifestations. There are disparities in its manifestations conditioned by sex, age of onset, and serological characteristics. The ethnic origin of the patients may be a conditioning factor for different organic manifestations, immunological markers, and outcomes.ObjectivesOur objective was to evaluate the clinical and serological differences in Caucasian vs. Latin American patients in a multiethnic Spanish single-center SLE cohort.MethodsSingle-centre retrospective observational study from a Spanish Lupus Cohort of adult SLE patients fulfilling the 2019 EULAR/ACR Classification Criteria. Only patients of Caucasian or Latin American origin were included.ResultsThe study included 205 patients: 186 (90.7%) Caucasian and 19 (9.3%) Latin American. The mean age at diagnosis was 35.5 years. The female/male ratio was 9:1 in the Caucasian group and 19:1 in the Latin American group (ns). Serous and cutaneous involvement was similar between groups. The presence of arthralgia was also similar (ns) but there were statistically significant differences with the presence of arthritis (p=0.008). Severe hematologic manifestations were also more frequent in Latin American patients but only statistically significant for autoimmune hemolytic anemia (AIHA). Lupus nephritis and end-stage renal disease (ESRD) were two-fold and four-fold more common in Latin American patients. Among the immunological findings: hypocomplementemia, Anti-Sm, and anti-histones were differential markers between the two groups. Anti-RNP was also more frequent in the Latin American group (ns). Regarding treatments, there were no relevant differences between steroids and antimalarials. There were also no disparities in outcomes measured by activity (SLEDAI), cumulative damage (SDI), low activity (LLDAS), remission (DORIS), or death in our cohort.Table 1.Caucasian vs. Latin American SLE patientsCaucasianLatin Americanp-valueOdds ratio (IC95%)Serositis (%)22.58 %26.32 %p=0.712Skin involvement (%)65.59 %52.63 %p=0.261Arthritis (%)24.32 %52.63 %p=0.0082.39 (1.06-5.38)AIHA (%)0.00 %5.26 %p=0.00228.69 (1.13-728.60)Lymphopenia (%)34.95 %52.63 %p=0.084Immune thrombocytopenia (%)4.30 %10.53 %p=0.230Neurolupus (%)20.97 %10.53 %p=0.278Glomerulonephritis (%)18.82 %42.11 %p=0.0182.51 (1.05-6.02)ESRD (%)3.76 %15.79 %p=0.0204.20 (1.01-17.58)Low C3 (%)54.30 %89.47 %p=0.0031.65 (0.82-3.31)Low C4 (%)49.46 %84.21 %p=0.0041.70 (0.84-3.46)Low vitamin D (%)11.29 %26.32 %p=0.0612.33 (0.79-6.89)High DNAds (%)61.29 %63.16 %p=0.404Anti-Sm (%)12.37 %36.84 %p=0.0042.98 (1.13-7.85)Anti-Ro (%)26.34 %31.58 %p=0.624Anti-RNP (%)8.06 %21.05 %p=0.0632.61 (0.79-8.66)Anti-histones (%)4.30 %21.05 %p=0.0034.89 (1.35-17.77)Antiphospholipid antibodies (%)45.16 %42.11 %p=0.799Steroids (%)88.71 %94.74 %p=0.419Antimalarials (%)94.05 %89.47 %p=0.436SLEDAI≥6 (%)34.41%26.32%p=0.477SDI ≥1 (%)70.43 %68.42 %p=0.855LLDAS (%)60.99 %66.67 %p=0.637DORIS (%)48.09 %38.89 %p=0.456Death (%)1.61 %0.00 %p=0.577ConclusionIn our multiethnic Spanish single-center cohort, SLE patients of Latin American origin had a higher frequency of arthritis, glomerulonephritis, and AIHA. They also presented a higher frequency of hypocomplementemia, anti-Sm, and anti-histones at the immunological level. However, these clinical and serological differences did not correlate with outcomes of activity, damage, remission, or mortality. Future studies are needed to assess the definitive effect of ethnicity on SLE.