Infliximab in Hispanics: characterization of response to infliximab in an ethnic minority with Crohn's disease

RESUMO

PURPOSE: The incidence and prevalence of Crohn's disease (CD) varies geographically and with racial/ ethnic background. The highest frequency of occurrence is in North America and Northern Europe. Incidence is highest among Caucasians, lower in blacks and Hispanics, and lowest in Asians. However in the mid-1980s and 1990s, the incidence and prevalence increased in continental Europe, the Middle East, the Pacific Rim, Africa, and Latin America. An increase in the incidence of CD has been noted in Puerto Rico, although our population differs genetically from other described CD populations. A study in our population showed lower prevalence of ASCA and no NOD2 in our CD patients. Infliximab, a TNFa antibody, is effective in refractory inflammatory CD and in fistulizing disease. Since limited data exists regarding CD in Hispanics, the fastest growing minority group in the United States, we designed this retrospective study with patients treated with infliximab at our institution. We wanted to determine if the response to infliximab in genetically admixed Hispanics differed from that previously reported. METHODS: Baseline characteristics, infusion related information and clinical response was abstracted from medical records. Clinical response was classified as complete response, partial response, and nonresponse. RESULTS: The study included 15 patients treated for refractory inflammatory disease, 9 for fistulizing disease, and 11 for both. The positive response rate was 83%(29/35) and the non response rate was 17%(6/35). Overall the patients with complete, partial, and no response were 13/35(37%), 16/35(46%), and 6/ 35(17%), respectively. No statistically significant association was found between response and disease location. Significant association was found between response and fistula type (p = 0.02). Steroid withdrawal was possible in 21/31 patients (68%). In terms of safety, 9/35 patients (26 %) suffered an adverse reaction, 4 patients required therapy discontinuation. CONCLUSION: This study suggests that infliximab has similar global response, allowance of steroid withdrawal and safety in Hispanics as in other populations. Ethnicity does not seem to influence response rate to infliximab.