Clinical and sociodemographic factors associated with lupus nephritis in Colombian patients: A cross-sectional study.

INTRODUCTION: Over the past decades, incidence of SLE (Systemic Lupus Erythematosus) has increased due to early case detection and improved survival of patients. SLE presents at an earlier age and has a more severe presentation in African-American, Native American, Asian, and Hispanic populations. Worldwide, lupus nephritis (LN) is observed in 29-60% of SLE patients, it has a negative impact in renal survival and patient mortality. Several cohorts have established potential risk factors associated with lupus nephritis, such as male sex, serological markers, and some extra-renal manifestations. OBJECTIVES: To describe sociodemographic, clinical, immunological, and environmental risk factors in Colombian SLE patients and to compare the population with and without nephritis, in order to establish risk factors and possible associations. MATERIALS AND METHODS: A total of 1175 SLE patients participated in this study. During medical care, an interview and structured survey was conducted and later registered in a database. Sociodemographic, clinical, immunological, and environmental exposure variables were analyzed. Bivariate and multivariate analyses were performed using presence of LN as an outcome. RESULTS: Prevalence of LN was 38.7%. Variables significantly associated with LN included being male (OR 1.98), a duration of SLE>10 years (OR 1.48), positive anti-DNA (OR 1.34), positive anti-Sm (OR 1.45), and smoking (OR 1.66). Being non-smoker was a protective factor (OR 0.52). CONCLUSION: This study describes potential factors associated with lupus nephritis in a Latin American population. Smoking status could be a target for intervention as it is a modifiable risk factor. The association between being male and LN is observed in Latin-American populations such as presented here. Further research in other large-scale population studies and more efforts are needed to gain better insights to explicate these relationships.