The correlation between trajectories of serum C3 variability and clinical course in Pediatric-onset systemic lupus erythematosus

Objective: The aim of this study is to investigate the usefulness which 2-year trajectories of C3 variability have in predicting clinical remission and systemic corticosteroids (SCS) use in pediatric patients with systemic lupus erythematosus (pSLE).Methods: We recruited 189 confirmed pSLE patients from the electronic database of our hospital, all had undergone SCS treatment. The follow up period was 4.17-14.83 years. We used Group-Based Trajectory modeling to divide the patients into four different trajectory groups by their initial 2-year C3 variability. We divided the patients into groups A, B or C by their clinical course and SCS use. Statistical methods included Kruskal-Wallis and Chi-square tests and logic regression test.Results: There were 4 separate trajectories. The distribution of groups A, B and C in these 4 trajectories showed a significant difference (p = 0.005). Initial C3 and C4 levels in these 4 revealed significant differences (p <= 0.001, p <= 0.016). When compared to other trajectories, trajectory1 showed a higher risk for persistent SCS use (p < 0.05). The distributions of severe clinical manifestations, including proteinuria, hematuria, CNS involvement and thrombocytopenia were different in these 4 trajectories (p = 0.003). Nevertheless, none of the above manifestations contributed to the risk of persistent SCS use.Conclusions: We have found 4 distinct C3 trajectories in pSLE patients. Distributions of clinical outcome groups were different in these 4 trajectories. Patients with trajectory1 displayed a higher risk for persistent SCS use, thus an earlier institution of immunosuppressant(s) and biological agents can be considered for these children.

Automated summary

The aim of this study was to investigate the usefulness of 2-year trajectories of C3 variability in predicting clinical remission and SCS use in pediatric patients with pSLE. The results showed that different C3 trajectories were associated with different clinical outcome groups, with patients in trajectory 1 at a higher risk for persistent SCS use. Therefore, early initiation of immunosuppressants and biological agents may be considered for these children.