| Background. Henoch–Schönlein purpura (HSP) is a multisystem, small vessel, leucocytoclastic vasculitis.
It is predominantly a childhood vasculitis, rarely reported in adults. Studies have shown that several different
genetic factors such as genes involved in inflammatory system and renin-angiotensin system (RAS) are
important in the pathogenesis of Henoch–Schönlein purpura.
Objectives. The purpose of this study was to evaluate the independent effect of 3 gene polymorphisms
including CCL2-2518 C/T, VEGF-634G/C and ACE(I/D) with HSP disease and their possible joint interactions
in developing the disease.
Material and methods. In this case-control study 47 HSP cases and 74 unrelated healthy controls were
enrolled for evaluation. All individuals were genotyped for CCL2-2518C/T, VEGF-634G/C and ACE(I/D) gene
polymorphisms. The possible association of these polymorphisms with susceptibility to develop HSP disease
independently and in different joint combinations was evaluated.
Results. The frequencies of TT genotype and T allele of CCL2-2518C/T gene polymorphism and CC genotype
and C allele of VEGF-634G/C gene polymorphism were significantly high in HSP children (p-values = 0.005
and = 0.007 respectively). Interestingly, studying the joint interaction of these 2 genotypes (CC genotype
of VEGF G-634C and TT genotype of CCL2 C-2518T) in this cohort showed a more significant effect in the
development of the disease (p < 0.000, OR = 6.009). The frequency of TT genotype of CCL2 gene when
combined with II genotype of ACE gene in HSP children was significantly higher (p < 0.000, OR = 4.213).
Conclusions. The results of this pilot study provide evidence of the possible gene–gene interaction effects
of CCL2, VEGF and ACE genes in developing HSP disease. |