CALR and alkaline phosphatase measurement: Pediatric-onset SLE-related AP had higher rate of severe AP (60% versus 11.76%, P = 0.014), higher serum amylase level (17.55 ± 16.09 versus 6.53 ± 5.42, P = 0.007), lower percentage of positive anti-Ro antibody (25% versus 84.62%, P = 0.01), and lower rate of anti-La antibody (0 versus 53.85%, P = 0.02) compared to adult-onset SLE-related AP.