The clinical characteristics of low C4 alone in patients with systemic lupus erythematosus

Excerpt

Systemic lupus erythematosus (SLE) is a complex autoimmune disease, and one of the pathogenic mechanisms of SLE is the formation of an immune complex that then activates the complement system, resulting in complement consumption. Therefore, hypocomplementemia often occurs in patients with SLE. In clinical practice, patients with hypocomplementemia may exhibit low levels of C3 or C4 alone, and the pathogenic mechanism and clinical characteristics of these patients may differ from those of patients that show low levels of both C3 and C4. A study in Japan found a lower prevalence of arthritis, serositis, and nephritis in patients with low C3 levels alone [1]. Although SLE with low levels of C4 alone is common in clinical practice [2, 3], the potential features of SLE patients with low C4 levels alone remain unclear. In this study, we explored the clinical characteristics of SLE patients with low C4 alone. …