Angiotensinogen M235T Polymorphism in Children with Henoch-Schonlein Purpura Nephritis

ABSTRACT

PURPOSE: Henoch-Schonlein purpura(HSP) nephritis has a variable range of prevalence from 25 to 50% among HSP patients and is a common cause of chronic glomerulonephritis in children. In our study, we evaluated the distribution and the association of the angiotensinogen(AGT) M235T polymorphism with the clinical manifestations, particularly proteinuria in children with HSP with or without nephritis. METHODS: The AGT M235T polymorphism was determined in children with HSP nephritis (n=33) or HSP without nephritis(n=28) who had been diagnosed at Busan Paik hospital from January 1996 to June 2001. The M235T polymorphism of the AGT gene was determined by PCR amplification of the genomic DNA. RESULTS: The M235T polymorphism of AGT gene frequency was MM75%, MT25%, TT0% in HSP and MM64%, MT36%, TT0% in HSP nephritis, there was no significant differences in the genotype and allele frequencies between the two groups. No significant differences in clinical manifestations at onset and last follow-up were seen between the two genotypes. When statistical analysis was done according to the presence of the M allele, the amount of 24-hour urinary protein excretion and the incidence of moderate to heavy proteinuria(>500 mg/m2/day) at onset and at last follow-up were higher in the MT genotype than in those of in the MM genotype but these difference were not statistically significant. CONCLUSION: We suggest a lack of association between M235T polymorphism of the AGT gene and clinical manifestations in children with HSP nephritis. However, further follow-up studies based on sufficient number of patients and long term follow up periods are necessary to confirm the role of M235T polymorphism of AGT gene in children with HSP nephritis.