Association of Higher Defensin β-4 Genomic Copy Numbers with Behçet's Disease in Iraqi Patients

Behçet's disease (BD) is an immune-mediated small vessel systemic vasculitis. Human β-defensins are antimicrobial peptides associated with many inflammatory diseases and are encoded by the β-defensin family of multiple-copy genes. However, their role in BD necessitates further investigation. The aim of the present study was to investigate the possible association of BD in its various clinical forms with defensin β-4 (DEFB4) genomic copy numbers.

This case-control study was conducted from January to September 2011 and included 50 control subjects and 27 unrelated Iraqi BD patients registered at Baghdad Teaching Hospital, Bagdad, Iraq. Copy numbers of the DEFB4 gene were determined using the comparative cycle threshold method by duplex real-time polymerase chain reaction technology at the Department of Dermatology of Jena University Hospital, Jena, Germany.

DEFB4 genomic copy numbers were significantly higher in the BD group compared to the control group (P = 0.010). However, no statistically significant association was found between copy numbers and clinical variables within the BD group.

The DEFB4 copy number polymorphism may be associated with BD; however, it is not associated with different clinical manifestations of the disease.