Background: Children represent 10-20% of all systemic lupus erythematosus (SLE) patients. Their clinical manifestations and outcomes vary with age. We aim to clarify the relationship between pubescent status and the clinical manifestations of pediatric SLE.
Methods: In this study, pediatric SLE patients were divided into three groups, based on age at disease onset (≦8, 8-13 & 13-18 years), defined as prepubescent, pubescent and postpubescent, respectively. Initial clinical manifestations and laboratory characteristics at diagnosis were analyzed.
Results: Ninety-six patients were entered into the study: 8 had disease onset before age 8, while 49 were between 8-13 and 39 of them were 13-18. Female predominance was noted in all three groups (2.5-7.0:1). Postpubescents showed significantly more renal involvement and lymphopenia, along with lower levels of C3 and C4, when compared with prepubescents. They also showed significantly more lymphopenia when compared with pubescents. Pubescents showed significantly more renal involvement, leukopenia and lupus anticoagulant (LAC) positivity, along with lower C3 and C4 levels, when compared with prepubescents. Pubescents also showed significantly higher anti-Sm antibody positivity when compared with postpubescents. Prepubescents showed significantly more splenomegaly and anti-Jo-1 antibody positivity when compared with those of pubescents. The results showed that the disease activity (SLEDAI-2K score) correlated positively with age at disease onset and negatively with disease duration before diagnosis (p = 0.011).
Conclusions: Age at disease onset is related to initial manifestations in pediatric SLE patients at our center. Certain parameters such as renal involvement, splenomegaly, low C3 level, low C4 level, lymphopenia, leukopenia, and anti-Sm & anti-Jo-1 antibody were found to be significantly different among the age groups. Renal involvement might be the key symptom that varies with age.