Lymphopenia Is a Risk Factor in the Progression of Carotid Intima-Media Thickness in Juvenile-Onset Systemic Lupus Erythematosus

Objective. To characterize the atherosclerotic risk factors in the progression of subclinical atherosclerosis in patients with juvenile-onset systemic lupus erythematosus (SLE). Methods. This was a longitudinal study of 76 patients with juvenile-onset SLE. Carotid arteries were evaluated using ultrasonography at baseline and at followup visits at 6-month intervals over the 6-year study period. Clinical and laboratory parameters, disease activity, treatment, and traditional risk factors for atherosclerosis were evaluated. Data were analyzed using generalized estimating equations. Results. The mean +/- SD age of the patients at baseline was 15.01 +/- 3.48 years and the mean +/- SD disease duration was 2.65 +/- 2.5 years. The mean +/- SD duration of followup was 3.74 +/- 1.24 years. The mean +/- SD intima-media thickness (IMT) of the common carotid arteries differed significantly between the patient and control (n = 38) groups (0.63 +/- 0.08 mm versus 0.54 +/- 0.06 mm; P < 0.001). The presence of lymphopenia at diagnosis and at baseline and higher levels of serum creatinine and C-reactive protein at baseline were positively associated with progression of carotid IMT (P = 0.006, P = 0.043, P = 0.037, and P = 0.049, respectively). In multivariate analysis, only lymphopenia at baseline and at diagnosis were consistently associated with progression of IMT (P = 0.012 and P = 0.045, respectively). Conclusion. In patients with juvenile-onset SLE, some nontraditional risk factors for the progression of subclinical atherosclerosis were identified. Lymphopenia was the only independent risk factor for the progression of IMT. The pathogenic mechanisms warrant further investigation.