Desloratadine Efficacy in Relation to GSTM1 and GSTT1 Polymorphic Genes in Chronic Spontaneous Urticaria

The etiopathogeny of chronic spontaneous urticaria (CSU) is not well defined. Allelism in glutathione S-transferase GSTM1 and GSTT1 has been suggested as a risk factor. Desloratadine is the first-line treatment for this disease.

This study aimed to investigate the efficacy of a first-line treatment: desloratadine 5 mg/day on antioxidant status and clinical assessment in Tunisian patients with CSU and to identify possible associations between GSTT1 and GSTM1 genotypes and susceptibility to CSU.

Sixty patients with CSU and 60 age- and gender-matched healthy controls were included in the study. We calculated the urticaria activity score (UAS) and assessed the antioxidant parameters (total antioxidant status [TAS], glutathione S-transferase [GST], SOD, CAT, GPx]). Multiplex PCR was performed to find the relationship between GSTM1 and GSTT1 polymorphisms with CSU susceptibility.

At baseline, GST, GPx, CAT, SOD activities, and TAS were significantly lower in CSU patients compared to healthy controls (P < 0.05). After treatment, GST, GPx, CAT, SOD activities and TAS were significantly increased in patients compared to those before treatment (P < 0.001). We observed a significant association in null alleles of GSTM1. Before treatment, GST activity was significantly lower in patients having GSTM1+ genotype than those having GSTM1- genotype (P = 0.001). After treatment, TAS and antioxidant enzymes GST, GPx, SOD, and CAT were significantly elevated in patients having GSTM1- genotype than those having GSTM1+ genotype (P < 0.05).

These results suggest the impact of GSTM1 and GSTT1 on CSU susceptibility and desloratadine efficacy in Tunisian patients.