Abstract Objective To explore the relationship between urine retinol-binding protein (RBP), N-acety 1-B-D-amino-clucosidic enzyme (NAG) and renal tubular injuries in children with anaphylacoid purpura (AP) and purpura nephritis (PN). Methods Using ELISA, the concentration of urine RBP and NAG were determined. Ninty-two cases were divided into three groups: Group 1 (23 cases of AP), Group 2 (31 cases of PN) and Group 3 (38 normal children). Results There was a significant difference in urine RBP concentration between Group 1 ( 20.9 ± 17.12 μg/mmol Cr) and Group 3 ( 10.3 ± 4.8 μg/mmol Cr), ( P < 0.05 ), and Group 2 ( 25.7 ± 22.8 μg/mmol Cr) and Group 3 ( P < 0.01 ). No difference was noted between the first and second groups ( P > 0.05 ). As to the urine NAG capacity, there was no difference between the first group ( 1.5 ± 0.8 U/mmol Cr) and the control group ( 1.5 ± 0.9 U/mmol Cr), ( P > 0.05 ), a prominent difference was noted between the second group ( 3.6 ± 4.4 U/mmol Cr) and the control group, ( P < 0.01 ), and there was a difference between the first group and the second group as well, ( P < 0.05 ). Conclusions Despite normal urinary findings in AP patients there exist varing degree of proximal renal tubule damage, more so in the PN, in different levels if the urine routine has changed, and so would be the distal renal tubule.
