Azatioprina na doença inflamatória intestinal: fatores preditivos da resposta sustentada a longo prazo

Introduction

Azathioprine (AZA) is an option for maintenance therapy in Inflammatory Bowel Disease (IBD). However, the factors which influence or predict its response are poorly understood.

Aim

Evaluate the predictive factors for a successful long‐term therapeutic response of AZA.

Methods

Retrospective analysis of all patients with IBD followed up in our hospital treated with AZA (2‐2.5 mg/Kg/day) due to steroid dependent or resistent disease or, in Crohn disease (CD), due to fistulizing behavior or post‐surgery. We recorded the type of disease (DC/ ulcerative colitis (UC), indeterminate IBD), clinical parameters, laboratory parameters (LP) – WBC, CRP, hemoglobin, platelets and MCV – before and after 3 months of treatment, as well as concomitant usage of 5‐ASA and steroids. The treatment was considered effective when patients maintained control of the disease by clinical/endoscopic criteria, with continued maintainance of AZA or cessation of therapy after 3 months of treatment, and without escalation of therapy. We excluded patients who show intolerance to AZA in the first 3 months and patients treated concomitantly with biological agents.

Results

72 patients (37 women and 35 men); mean age 38.0 ± 13.8 years; 35 patients with CD, 34 with UC and 3 with indeterminate IBD. The average duration of treatment with AZA was 35.1 ± 30.6 months. AZA was effective in 48 patients (66.7%). The age at onset of AZA predicts therapeutic sucess (R = 0.303, p = 0.019). The sex, type of disease and LP before treatment did not correlate with efficacy. The LP after 3 months of therapy correlated with therapeutic sucess in the long‐term: WBC (r = –0.295, p = 0.013), CRP (r = –0.332, p = 0.005), hemoglobin (r = 0.307, p = 0.010), platelets (r = –0.360, p = 0.003) and MCV (r = 0.255, p = 0.047). In combination, LP predict the efficacy of treatment (R = 0.517, p = 0.005). There is also an association between the location of UC (r = –0.381, p = 0.026), as well as the duration of concurrent treatment with 5‐ASA (r = 0.258, p = 0.029) and the suspension of steroids (r = 0.265, p = 0.04) with the efficacy of the treatment.

Conclusion

AZA proved to be an effective treatment in the majority of patients with IBD. The old age of onset of the therapy and LP at 3 months were predictive of a sustained response of AZA.