<h3>Background</h3> Systemic Lupus Erythematosus (SLE) is an autoimmune disease, with multiple organs and system involvement. The most usual haematological findings are anaemia, leukopenia, and thrombocytopenia. The prevalence of SLE in Colombia was 8.77 per 10 000 persons between 2012 and 2016[.¹ <h3>Objectives</h3> To evaluate the haematological alterations in a cohort of patients with SLE in Bucaramanga, Colombia. <h3>Methods</h3> A retrospective cohort study of 149 patients diagnosed with SLE according to the Systemic Lupus International Collaborating Clinics (SLICC) criteria. Descriptive analysis with frequencies, measures of central tendency and dispersion was done using Stata 12.0 software. The primary outcome was the presence of cytopenia, the secondary outcomes were anaemia, leukopenia, and thrombocytopenia. In the group comparison analysis, a chi-square test was used for qualitative variables and Wilcoxon or T student test for quantitative variables according to their distribution. Bivariate analysis using logistic regression with OR measurement, <i>p</i>-value, and confidence intervals was performed. <h3>Results</h3> 82.5% were women, average age was 36.8 years. The primary outcome was found in the 79.8%, anaemia in the 76.5%, thrombocytopenia in the 22.1% and leukopenia in the 18.7%. In group comparison analysis (cytopenia vs no cytopenia) a statistical difference was found in the variables sex (p<i>=</i>0.023), skin involvement (p=0.003), acute pneumopathy (p=0.050), activity of the disease measured by the ECLAM scale (p=0.037) and anti-DNA antibody titers (p=0.032). In the bivariate analysis, there was an increased risk of cytopenias with statistical significance in male patients (OR: 3.82), ECLAM score greater than 5(OR: 4.75) and strongly positive anti-DNA antibodies (OR: 3.97). Regarding leukopenia, there was an association with antiphospholipid syndrome (OR: 2.75), ECLAM greater than 5 (OR: 2.51), SLEDAI MEX greater than 10 (OR: 2.35) and strongly positive anti-DNA antibodies (OR: 2.36). Likewise, an increased risk of mortality was found in patients with leukopenia (OR: 3.92). In the case of thrombocytopenia, an association was found with a pericardial alteration (OR: 2.46), ECLAM greater than 5 points (OR: 3.65), SLEDAI MEX greater than 10 points (OR 2.42). An association with mortality was also observed (OR: 2.97). The risk of presenting anaemia was increased with the variables man (OR: 4.4), ECLAM greater than 5 points (OR: 3.14) and strongly positive anti-DNA antibodies (OR: 3.25). <h3>Conclusions</h3> This is the first Colombian study that evaluates haematological alterations in patients with SLE. The most frequent cytopenia was anaemia. It is possible to identify variables that can predict the appearance of cytopenia, such as the increase in the activity of the disease, which is susceptible to intervention. It is noteworthy that both leukopenia and thrombocytopenia are markers of mortality in patients with SLE. <h3>Reference</h3> [1] Fernandez-Avila D, Rincon-Riaño, D (2017) Prevalencia y caractersiticas demograficas del lupus eritematoso sistemico en Colombia, segun informacion del sistema integral de informacion de la proteccion social. Abstrac presentation. Bogotá, Colombia. <h3>Acknowledgements</h3> This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors <h3>Disclosure of Interest</h3> None declared