MCP-1, CCR2 and CCR5 Polymorphisms in Tunisian Patients with Atopic Asthma

Chemokines and their receptors play an important role in the late inflammatory stage of asthma. In this study, we aimed to investigate polymorphisms of MCP-1 (CCL2), CCR2 and CCR5 which can affect qualitatively and/or quantitatively their production and thus influence both susceptibility and severity of asthma and its clinical and biological features. MCP-1 (A/G -2518), CCR2 (+/64I), CCR5 (G/A -59029) and CCR5 (Delta 32) polymorphisms were evaluated by PCR in 107 Tunisian patients with asthma and 169 healthy controls. No significant association was found between the four investigated polymorphisms and asthma. Nevertheless the haplotype MCP1*AG/CCR2*+/+ was significantly l ess frequent in patients (20.5%) compared to controls (32.5%) (p=0.03; OR=0.54; 95% CI : 0.29-0.98). Whereas no difference was observed in CCR2/CCR5 haplotypes between patients and controls. Analysis of polymorphisms with clinical and biological features showed that the concomitant presence of MCP-1*G/CCR2*64I alleles was less frequent in severe forms (4.34%) compared to moderate disease (12%) but the difference was not significant (p=0.27). No association was observed between the four polymorphisms and the presence of atopic rhinitis or atopic conjunctivitis and an elevated rate of serum IgE over 200 IU/ml. Additional effects of MCP-1 and its receptor CCR2 polymorphisms seem to be involved in disease susceptibility to asthma in Tunisian patients; nevertheless they could be protective against its severe forms.