Abstract: Objective To establish age- and gender-specific reference intervals for 8 common liver function tests in healthy children aged 3 months to 18 years in Chongqing by dry chemical method.Methods Healthy children aged 3 months to 18 year were selected and divided into 3 months to 1 years, -3 years, -6 years, -12 years and -18 years old groups according to the rule of growth and development. Serum TB, TP, ALB, ALT, AST, ALP, GGT and LDH were detected by the VITROS 5600 system. Differences in test results of different ages and genders were compared and the reference intervals were calculated using nonparametric methods.Results During the study period, 3,758 healthy children aged 3 months to 18 years met the inclusion and exclusion criteri; 35 unqualified specimens were excluded, and 3,723 eligible specimens were included in the analysis. There were 241 children in the 3 months to 1 year, 251 in the -3 years, 939 in the -6 years old, 1,672 in the -12 years old, and 620 in the -18 years old. ① TP in early childhood, TP and AST in the preschool, TB, ALT, AST, GGT and LDH in the school age, and TB, ALB, ALT, AST, ALP, GGT and LDH in the adolescence were statistically significant between boys and girls (P<0.05), and in the adolescence boys were significantly higher than in those girls. ② ALT, AST and LDH results were negatively correlated with age, and TB, TP, ALB, ALP and GGT were positively correlated with age. ③ The reference intervals of serum TB(μmol·L^-1): 3 months to 1 year 1.0-11.0,1-18 years 1.0-11.0; reference intervals of TP (g·L^-1): 3 months to 3 years 60.2-74.2, -6 years 61.3-78.2, -12 years 62.8-81.5, -18 years 64.9-82.4; reference intervals of ALB (g·L^-1): 3 months to 18 years 38.4-49.5; reference intervals of ALT (U·L^-1): 3 months to 1 year 15.8-48.4,1-12 years 14.0-42.2, -18 years 14.7-45.7 (male), 12.5-44.8 (female); reference intervals of AST (U·L^-1): 3 months to 1 year 23.9-54.3, -3 years 26.4-50.6,-6 years 22.8-45.8, -12 years 18.9-41.2, -18 years 15.7-36.8 (male), 14.2-33.7 (female); reference intervals of ALP (U·L^-1): 3 months to 12 years 130.0-318.5, -18 years 124.2-416.1 (male), 79.9-320.3 (female); reference intervals of GGT (U·L^-1): 3 months to 1 year 10.0-30.0,1-12 years 9.3-21.3, -18 years 9.6-28.7 (male), 9.5-26.2 (female); reference intervals of LDH (g·L^-1): 3 months to 3 years 165.9-266.0, -6 years 155.3-256.2, -12 years 142.9-240.9, -18 years 134.3-225.3 (male), 111.3-207.0 (female).Conclusion There are differences in liver function levels among healthy children aged 3 months to 18 years in Chongqing. The age- and gender-specific pediatric reference intervals are important for the diagnosis and treatment of related diseases.

Key words: Children, Dry chemical, Liver function, Reference interval