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

Abstract

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 potentialfactors associated with lupus nephritis in a LatinAmerican 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.

Introducción: En las últimas décadas la incidencia del Lupus eritematoso sistémico (LES) se ha incrementado debido a la detección temprana y su mejoría en la supervivencia. La nefritis lúpica (NL) se observa en el 29% a 60% de los pacientes con LES, teniendo un impacto negativo en la supervivencia renal y la mortalidad. Varias cohortes han establecido factores de riesgo asociados con la NL, como el sexo masculino, marcadores serológicos y algunas manifestaciones extrarrenales.Objetivos: Describir los factores de riesgo sociodemográficos, clínicos, inmunológicos y ambientales en pacientes colombianos con LES y comparar la población con y sin NL para establecer posibles asociaciones. Materiales y métodos: Se incluyeron 1175 pacientes con LES, se analizaron variables sociodemográficas, clínicas, inmunológicas y ambientales, tomadas de bases de datos de registros cínicos. Los análisis bivariados y multivariados se realizaron utilizando la presencia de NL como desenlace. Resultados: La prevalencia de NL fue del 38,7%. Las variables significativamente asociadas con NL incluyeron sexo masculino (OR 1.98), una duración del LES > 10 anos ˜ (OR 1.48), anti-ADN positivo (OR 1.34), anti-Sm positivo (OR 1.45) y tabaquismo (OR 1.66), mientras que la ausencia de exposición al tabaco se comportó como factor protector (OR 0.52). Conclusión: Se describen los factores potenciales asociados con NL en una población latinoamericana. El tabaquismo se presenta como un factor de riesgo susceptible de intervención. El sexo masculino y su asociación con NL ya ha sido reportado en otras poblaciones latinoamericanas. Se requieren investigaciones a gran escala en otras poblaciones para explicar mejor estas asociaciones.