Chemokine MCP1/CCL2 gene polymorphism influences Henoch-Schönlein purpura susceptibility in Iranian Azeri-Turkish patients.

Background: Henoch-Schönlein purpura (HSP) is the most common small-vessel vasculitis and mainly affects children. Although its pathophysiology is unknown, several studies have indicated the possible involvement of infections and genetic factors in the development of HSP. The human leukocyte antigen (HLA) gene family and several other genes involved in the inflammatory system have been studied. The CCL2 gene, encoding chemokine monocyte chemo-attractant protein 1 (MCP-1/CCL2), is one of several cytokine genes clustered on chromosome 17. The encoded protein displays chemotactic activity for monocytes.

Methods: This is a case-control study comparing 36 children diagnosed with HSP within the Iranian Azeri-Turkish ethnic population and 50 healthy adults from the same ethnic group. CCL2, C-2518T polymorphism genotypes were determined by polymerase chain reaction and by PVUII restriction enzyme analysis and subsequent agarose gel electrophoresis.

Results: Our results showed a significant association between the allelic and genotypic frequency of this gene and HSP disease in this cohort. The results of this study indicate that frequencies of the T allele of CCL2 (P = 0.015) and the TT genotype (P = 0.004) are significantly higher in HSP patients. A comparison of clinical symptoms and laboratory data with CCL2 C-2518T polymorphism showed that patients with the TT genotype presented a higher clinical score and more severe clinical features.

Conclusions: MCP1/CCL2 C-2518T gene polymorphism is associated with susceptibility to HSP. This is the first study to report a significant association between MCP1/CCL2 C-2518T and a susceptibility to HSP in this population.