Sociodemographic, clinical, and biochemical characteristics of patients who presented with and without lupus nephritis in a cohort of Mexican patients with systemic lupus erythematosus in a referral centre

Abstract

Introduction

Systemic lupus erythematosus (SLE) is an autoimmune inflammatory disease that presents great clinical heterogeneity, so that up to 60% of patients may develop lupus nephropathy (LN).

Objective

To identify demographic, clinical, and biochemical characteristics of patients presenting with and without lupus nephritis at the time of SLE diagnosis in a cohort of Mexican patients

Materials and methods

This is a cross-sectional, analytical, and single-centre study. Frequencies and percentages were used for categorical variables and the comparison was made with Pearson's Chi2 statistical test or Fisher's exact test. For the quantitative variables, their distribution was calculated and according to this, Student's t was used in case of normal distribution and Mann-Whitney U for those with free distribution.

Results

Of 160 patients, 79 (49.37%) had LN. These individuals had a higher prevalence of serositis (14.3 vs. 8.1%, p = 0.048) and arterial hypertension (40.50% vs. 24.6%, p = 0.033), while those without LN had a higher prevalence of rheumatoid arthritis and joint disease (6 vs. 1%, p = 0.052), allergies (43.2 vs. 20.25%, p = 0.002), infections (23.45 vs. 10%, p = 0.020), and lower levels of C3 (52.25±28.7 vs. 74.6±32.2 mg/dl, p < 0.001).

Conclusions

The characteristics described in our cohort are like those presented in other Latino and Asian series. However, the presence of concomitant infections at the time of SLE diagnosis has not been described and should be considered for future research.

Resumen

Introducción

El lupus eritematoso sistémico (LES) es una enfermedad inflamatoria autoinmune que presenta una gran heterogeneidad clínica, por lo que hasta el 60% de los pacientes pueden desarrollar nefropatía lúpica (NL).

Objetivo

Identificar las características demográficas, clínicas y bioquímicas de los pacientes que presentan NL y los que no la presentan en el momento del diagnóstico de LES en una cohorte de pacientes mexicanos.

Materiales y métodos

Estudio transversal, analítico y de un solo centro. Se realizaron pruebas de normalidad y se aplicó t de Student o U de Mann Withney dependiendo del tipo de variable. Para determinar la diferencia entre las varibales se realizó prueba de chi-cuadrado o prueba exacta de Fisher.

Resultados

De 160 pacientes, 79 (49,37%) presentaron NL, estos tuvieron una mayor prevalencia de serositis (14,3 vs. 8,1%, p = 0,048) e hipertensión arterial (40,50% vs. 24,6%, p = 0,033) y aquellos sin NL una mayor prevalencia de artritis reumatoide y afección articular (6 vs. 1%, p = 0.052), alergias (43,2 vs. 20,25%, p = 0,002), infecciones (23,45 vs. 10%, p = 0,020) y niveles más bajos de C3 (52,25±28,7 vs. 74,6±32,2 mg/dl, p < 0,001).

Conclusiones

Las características descritas en nuestra cohorte son similares a las presentadas en otras series latinas y asiaticas. Sin embargo, la presencia de infecciones concomitantes al momento del diagnóstico de LES no había sido descrita y debe ser considerada para el futuro de nuevas investigaciones.