Childhood Systemic Lupus Erythematosus: Clinical and Immunologic Patterns in Mexican Children

Introduction Systemic lupus erythematosus (SLE) is a complex autoimmune disease with heterogeneous clinical and laboratory features. The incidence increases markedly in women. The reason for the predominance of the female gender is still under study. The ethnicity could influence the clinical and serological features of SLE. Material and methods This is a retrospective, descriptive, and longitudinal study. We studied 89 patients diagnosed with childhood-onset systemic lupus erythematosus (cSLE) in our center in 2000-2020 for men and 2010-2020 for women. We investigated disease manifestations, ranging from clinical symptoms to renal involvement, at the time of diagnosis and compared them by gender. Results We studied 89 patients, comprising 23 males and 66 females. The mean age for both groups was 12 years. Concerning clinical manifestations, serositis exhibited a higher prevalence among males, while hair loss was more prominent among females. In the paraclinical evaluation, noteworthy differences were observed regarding average hemoglobin levels and the prevalence of positive anti-DNA antibodies. Males demonstrated an average hemoglobin level of 11.47 g/dL, whereas females displayed 9.84 g/dL (p=0.017). The prevalence of anti-DNA antibodies exhibited marked elevation in males, at 88.9%, compared to females' 42.9% (p=0.024). On a contrary note, our male cohort displayed heightened prevalence in using hydroxychloroquine, cyclophosphamide, and mycophenolate. Similarly, renal involvement presented a higher prevalence in males (100% against 83.3%), albeit lacking statistical significance. Nevertheless, significant disparities emerged in the occurrence of granular casts, proteinuria, and the average glomerular filtration rate, with males experiencing greater impact in each instance. Finally, it is noteworthy that the application of mycophenolate and azathioprine was more frequently observed among patients with renal involvement. Conclusion cSLE patients in our inception cohort showed statistical significance in dermatological and vascular manifestations, serositis, granular casts, low kidney glomerular filtration, and high proteinuria, which are predominant in male patients. Immunological features were predominantly positive in ds-DNA antibodies for male patients. Separation by gender for future studies might identify a better treatment strategy.