Establishment of children′s reference value of glucose-6-phosphate isomerase antigen determination

Objective To establish the critical value of glucose-6-phosphate isomerase(G6PI)antigen determination in children.Methods 775 healthy controls(age groups:≤3 years old,4-6 years old,7-9 years old and 9 years old;sex groups: girl and boy groups) and 53 patients with rheumatoid arthritis(RA) were enrolled.The concentration of G6PI antigen was determined by solid phase enzyme-linked immunosorbent assay(ELISA).The critical value of G6PI antigen was analyzed by receiver operating characteristic(ROC) curve.Results The concentrations of G6PI antigen from different age groups ≤3 years,4-6 years,7-9 years and 9 years were 0.126±0.069,0.127±0.079,0.129±0.072 and(0.126±0.072) mg/L respectively.There was no statistical difference in different age groups(P0.05).The concentrations of G6PI antigen were 0.124±0.089 and(0.123±0.065) mg/L in boy group and girl group with no statistical significance(P0.05).The concentration of G6PI antigen in RA group [(0.517±0.298) mg/L] was higher than that in healthy group [(0.127±0.073)mg/L,P=0.00].The specificity and sensitivity were 95.1%and 79.2%,when the critical value was 0.27 mg/L.The specificity and sensitivity were 96.2%and 65.4%,when the critical value was 0.32 mg/L.Conclusions The G6PI antigen concentration of children in Shenzhen is not affected by age and sex.With good specificity and sensitivity,0.27 and 0.32 mg/L may be the high reference values for RA.