Treatment of Crohn's disease: the "long" of it

Common misconceptions about 5-aminosalicylates and thiopurines in inflammatory bowel disease

Misconceptions are common in the care of patients with inflammatory bowel disease (IBD). In this paper, we state the most commonly found misconceptions in clinical practice and deal with the use of 5-aminosalicylates and thiopurines, to review the related scientific evidence, and make appropriate recommendations. Prevention of errors needs knowledge to avoid making such errors through ignorance. However, the amount of knowledge is increasing so quickly that one new danger is an overabundance of information. IBD is a model of a very complex disease and our goal with this review is to summarize the key evidence for the most common daily clinical problems. With regard to the use of 5-aminosalicylates, the best practice may to be consider abandoning the use of these drugs in patients with small bowel Crohn’ s disease. The combined approach with oral plus topical 5-aminosalicylates should be the first-line therapy in patients with active ulcerative colitis; once-daily treatment should be offered as a first choice regimen due to its better compliance and higher efficacy. With regard to thiopurines, they seem to be as effective in ulcerative colitis as in Crohn’ s disease. Underdosing of thiopurines is a form of undertreatment. Thiopurines should probably be continued indefinitely because their withdrawal is associated with a high risk of relapse. Mercaptopurine is a safe alternative in patients with digestive intolerance or hepatotoxicity due to azathioprine. Finally, thiopurine methyltransferase (TPMT) screening cannot substitute for regular monitoring because the majority of cases of myelotoxicity are not TPMT-related.

Efficacy of 6-mercaptopurine treatment after azathioprine hypersensitivity in inflammatory bowel disease

AIM: To investigate the efficacy of 6-mercaptopurine (6-MP) in cases of azathioprine (AZA) hypersensitivity in patients with inflammatory bowel disease.

METHODS: Twenty nine previously confirmed Crohn’s disease (CD) (n = 14) and ulcerative colitis (UC) (n = 15) patients with a known previous (AZA) hypersensitivity reaction were studied prospectively. The 6-MP doses were gradually increased from 0.5 up to 1.0-1.5 mg/kg per day. Clinical activity indices (CDAI/CAI), laboratory variables and daily doses of oral 5-ASA, corticosteroids, and 6-MP were assessed before and in the first, sixth and twelfth months of treatment.

RESULTS: In 9 patients, 6-MP was withdrawn in the first 2 wk due to an early hypersensitivity reaction. Medication was ineffective within 6 mo in 6 CD patients, and myelotoxic reaction was observed in two. Data were evaluated at the end of the sixth month in 12 (8 UC, 4 CD) patients, and after the first year in 9 (6 UC, 3 CD) patients. CDAI decreased transiently at the end of the sixth month, but no significant changes were observed in the CDAI or the CAI values at the end of the year. Leukocyte counts (P = 0.01), CRP (P = 0.02), and serum iron (P = 0.05) values indicated decreased inflammatory reactions, especially in the UC patients at the end of the year, making the possibility to taper oral steroid doses.

CONCLUSION: About one-third of the previously AZA-intolerant patients showed adverse effects on taking 6MP. In our series, 20 patients tolerated 6MP, but it was ineffective in 8 CD cases, and valuable mainly in ulcerative colitis patients.

Long-term results with azathioprine therapy in patients with corticosteroid-dependent Crohn's disease: open-label prospective study

BACKGROUND

A substantial number of patients with Crohn's disease (CD) become dependent on steroids after induction therapy. Treatment with azathioprine (AZA) may be beneficial in such patients. The present open-label study evaluated the long-term safety and efficacy of AZA in steroid-dependent CD patients.

METHODS

Adult patients with steroid-dependent CD were enrolled for AZA therapy over a 7-year period. The average dose of AZA was 2.0-3.0 mg/kg per day, adjusted according to clinical response and occurrence of adverse effects. Steroid therapy was tapered off according to a predefined schedule. Long-term outcome and adverse reactions were evaluated.

RESULTS

Sixty-nine patients were prospectively included. Steroid-free remission was achieved in 68-81% of patients, partial response in 14.5-27.3% and failure to respond to AZA in 4-15.9% over the initial 48 months. However, the rate of wean from steroid therapy decreased to 53-60% while the rate of failure increased from 6.7% to 17.6% after this period. A breakthrough of symptoms during continuous AZA therapy was common, particularly after 48 months on AZA. The mean leukocyte count at the end of 12 months of therapy was significantly lower in patients who achieved complete response on AZA than in the non-responders (5197 +/- 1250 cells/mm(3) vs 8340 +/- 1310 cells/mm(3), respectively; P < 0.01). Azathioprine was relatively well-tolerated and the incidence of serious adverse effects was small.

CONCLUSIONS

Azathioprine was relatively safe and moderately effective for long-term maintenance of steroid-free clinical remission in corticosteroid-dependent CD patients. Patients were more successfully weaned from prednisone treatment, and clinical remission was more often maintained during the first 48 months of AZA therapy. A significant decrease in the white blood cell count at the end of 12 months on AZA was the single factor associated with weaning from steroid dependence.

Biomarker discovery for inflammatory bowel disease, using proteomic serum profiling

Crohn's disease and ulcerative colitis known as inflammatory bowel diseases (IBD) are chronic immuno-inflammatory pathologies of the gastrointestinal tract. These diseases are multifactorial, polygenic and of unknown etiology. Clinical presentation is non-specific and diagnosis is based on clinical, endoscopic, radiological and histological criteria. Novel markers are needed to improve early diagnosis and classification of these pathologies. We performed a study with 120 serum samples collected from patients classified in 4 groups (30 Crohn, 30 ulcerative colitis, 30 inflammatory controls and 30 healthy controls) according to accredited criteria. We compared protein sera profiles obtained with a Surface Enhanced Laser Desorption Ionization-Time of Flight-Mass Spectrometer (SELDI-TOF-MS). Data analysis with univariate process and a multivariate statistical method based on multiple decision trees algorithms allowed us to select some potential biomarkers. Four of them were identified by mass spectrometry and antibody based methods. Multivariate analysis generated models that could classify samples with good sensitivity and specificity (minimum 80%) discriminating groups of patients. This analysis was used as a tool to classify peaks according to differences in level on spectra through the four categories of patients. Four biomarkers showing important diagnostic value were purified, identified (PF4, MRP8, FIBA and Hpalpha2) and two of these: PF4 and Hpalpha2 were detected in sera by classical methods. SELDI-TOF-MS technology and use of the multiple decision trees method led to protein biomarker patterns analysis and allowed the selection of potential individual biomarkers. Their downstream identification may reveal to be helpful for IBD classification and etiology understanding.