Significance of the weighted complement domain of the EULAR/ACR classification criteria in juvenile onset systemic lupus erythematosus.

Observation of more frequent clinical and serological activity with higher total scores from the EULAR/ACR classification criteria supported the higher scoring of patients with low C3 and C4 in the weighted criteria. However, since significant number of patients did not exhibit low complement C4, and the frequency of kidney involvement did not differ according to the weighted complement status, complement C3 might be suggested as a more important diagnostic tool in patients with juvenile onset SLE. Also, weighted complement status at onset did not seem to affect the disease outcomes.