Serum level of IGF-1 in children with Henoch-schoenlein purpura

Objective To investigate the clinical significance of detecting IGF-1 level in children with Henoch-schoenlein purpura(HSP) or Henoch-schoenlein purpura nephritis(HSPN).Methods Ninty children in total with HSP or HSPN and normal children were recruited.And they were divided into three groups:the HSP group with 31 cases,the HSPN group with 28 cases,and the control group with 31 cases.The serum level of insulin and insulin-like growth factor-1(IGF-1) was tested by enzyme linked immunosorbent assay(ELISA) respectively.At the same time,total urine protein level in 24 hours was determined in 28 HSPN children.Results(1) The serum level of IGF-1 in the control group was(0.272 2±0.107 1) ng/L,while that in the HSP group was(0.599 9±0.346 8)ng/L,and that in the HSPN group was(0.906 0±0.346 8)ng/L.There existed significant difference among the three groups(F=22.98,P0.05),and serum level of IGF-1 in the HSPN group was higher than that in the HSP group and the control group(P0.05).(2) Among 12 cases of children who underwent renal puncture biopsy,the highest serum level of IGF-1 was 1.376 ng/L,while the lowest level was 0.187 ng/L,and serum IGF-1 level has a tendency of becoming higher with the severity of histopathological changes.(3) Serum IGF-1 level of the HSPN children with proteinuria is higher than that of the HSPN children without proteinuria(P0.05).There was no significant difference between the serum IGF-1 level of the HSP children with and without hematuria(P0.05).(4) The serum IGF-1 level increases with the protein level in the uria becoming higher among HSPN group(P0.05).Conclusion Increasing serum level of IGF-1 was observed in the acute onset period of HSP,also this increasing level could be related to the degree of proteinuria,it thus can be an index for predicting early stage of glomerulus and nephric tubule injury.Therefore,serum level of IGF-1 may be indicative of a renal involvement in HSP.