DLG5 R30Q does not predict response to infliximab therapy in Hungarian patients with Crohn's disease

Aim: Recent data from Germany have suggested that specific haplotypic variants of the DLG5 gene on chromosome 10q23 are associated with susceptibility to inflammatory bowel disease (IBD). Since DLG5 has been implicated in maintaining intracellular signal transduction and cell-cell contact, it might be hypothesized that DLG5 affects inflammatory responses and, as a consequence, also response to anti-inflammatory therapy. In this study, we investigated the DLG R30Q variant allele and response to infliximab therapy in CD patients.

Methods: 60 unrelated CD patients (m/f: 25/35, age: 34.3±11.1 years, duration: 7.9±5.1 years). DLG5 R30Q was tested by PCR-RFLP. Detailed clinical phenotype was determined by review of the medical charts.

Results: 28.3% of CD patients treated with infliximab carried the 113A. Disease location was ileal in 6, colonic in 22 and ileocolonic in 32 patients. In addition, three patients had upper GI involvement. Disease behavior was inflammatory in 27 and penetrating in 33. The indication for infliximab was fistulizing disease in 23 patients and inflammatory, non-responsive to conventional therapy in 37. Overall, no association was found between the carriers and non-carriers of the 113A variant allele and short term response (assessed at week 8) to infliximab induction therapy (dose 5mg/bwkg; no response or worsening: 17.7% vs. 27.9%, partial response (CDAI decrease by ≥70 points and/or ≥50% decrease in the number of draining fistulae): 47.1% vs. 41.8%, remission (CDAI<150 or closure of all fistulas): 35.2% vs. 30.3%).

Conclusion: DLG5 R30Q variant allele did not predict the response to infliximab therapy in this cohort of Hungarian CD patients.