Treatment with infliximab is associated with increased markers of bone formation in patients with Crohn's disease.

OBJECTIVE: Osteoporosis is a common complication of Crohn's disease (CD). Glucocorticoid use and detrimental effects of inflammatory cytokines including tumor necrosis factor-alpha (TNF-alpha) can lead to osteoporosis. The aim of this study was to assess the ability of treatment with the TNF-alpha antagonist infliximab to increase bone formation as measured by surrogate markers of bone turnover in patients with active CD. METHODS: Sera from 38 prospectively enrolled CD patients were examined for levels of bone alkaline phosphatase (BAP), N-telopeptide of type I collagen (NTX), immunoreactive parathyroid hormone (iPTH), calcium, and pro-inflammatory cytokines at baseline and 4 weeks following infliximab infusion. Crohn's Disease Activity Index (CDAI), Inflammatory Bowel Disease Questionnaire (IBDQ), and glucocorticoid dose also were collected. RESULTS: In this cohort, CDAI and IBDQ scores were significantly improved at week 4 (P<0.001). Infliximab therapy was associated with an increase in BAP, a marker of bone formation (P=0.010), whereas NTX, a marker of bone resorption, was not increased (P=0.801). Among 22 patients who were taking glucocorticoids, mean glucocorticoid dose decreased 36% (P<0.001; -7.9 mg). CONCLUSIONS: Treatment with infliximab was associated with increased markers of bone formation (BAP) without increasing bone resorption (NTX). This effect may be due to a beneficial effect of TNF-alpha blockade on bone turnover, a beneficial effect on CD activity resulting in decreased glucocorticoid dose, or both. Studies of longer duration are needed to assess the effect of infliximab on bone mineral density.

An oral supplement enriched with fish oil, soluble fiber, and antioxidants for corticosteroid sparing in ulcerative colitis: a randomized, controlled trial.

BACKGROUND & AIMS: N-3 fatty acids from fish oil, antioxidants, and short-chain fatty acids (SCFAs) produced during the fermentation of soluble fiber may attenuate inflammation associated with ulcerative colitis (UC). We assessed the efficacy of a nutritionally balanced oral supplement enriched with fish oil, fructooligosaccharides, gum arabic, vitamin E, vitamin C, and selenium on disease activity and medication use in adults with mild to moderate UC. METHODS: A total of 121 patients with UC and a disease activity index (DAI) from 3-9 on a 12-point scale were block randomized for extent of disease and smoking status. In addition to their usual diet, patients consumed 18 oz of the oral supplement or a carbohydrate-based placebo formula each day for 6 months. Clinical and histologic responses were assessed at 3 and 6 months or at the final visit. A change in average prednisone use between groups was tested by using a linear mixed-effects model. RESULTS: Eighty-six patients completed the study. Baseline characteristics were not different between groups except for a higher total DAI score in the oral supplement group (7.3 +/- 1.3; n = 36) compared with the placebo group (6.2 +/- 2.0; n = 50) ( P < .05). Both groups showed significant and similar degree of improvement at 6 months in DAI (-2.5 for oral supplement and -2.8 for placebo) and histologic index (-1.9 for oral supplement vs. -2.0 for placebo). Both intent-to-treat and completed patients given oral supplement had a significantly greater rate of decrease in the dose of prednisone required to control clinical symptoms over 6 months as compared with the placebo group ( P < .001). CONCLUSIONS: The improvement in clinical response combined with a decreased requirement for corticosteroids suggest that this enriched oral supplement can be a useful adjuvant therapy in patients with UC.

Mutations in NOD2 are associated with fibrostenosing disease in patients with Crohn's disease.

BACKGROUND & AIMS: The clinical manifestations of Crohn's disease (CD) are diverse, ranging from fibrostenosing small-bowel disease to colon-predominant inflammation. These distinctions may represent genetic, immunologic, and microbial heterogeneity. NOD2 gene mutations in CD have been described recently and may alter innate immune responses. We hypothesized that NOD2 mutations may be associated with distinct phenotypic expressions of CD. METHODS: Two cohorts of consecutively identified patients referred to an inflammatory bowel disease center (n = 142 collected between 1993 and 1996; n = 59 collected between 1999 and 2001) were genotyped for 3 single nucleotide variants of NOD2-R675W, G881R, and 3020insC-and phenotyped for disease behavior, disease location, and serum immune markers. RESULTS: Univariate analysis showed that CD-associated NOD2 variants were significantly associated with fibrostenosing disease in each cohort (P = 0.049 and P = 0.002, respectively). When both cohorts were analyzed together, the association between NOD2 variants and fibrostenosing disease was more significant (P = 0.001). These relationships were observed in both Jews and non-Jews. Forty-six percent of patients with fibrostenosing disease carried at least 1 of these alleles, compared with only 23.5% of patients without fibrostenosing disease (odds ratio, 2.8; 95% confidence interval, 1.6-5.2). Multivariate and conditioning analyses showed a primary association between NOD2 allelic variants and fibrostenosing disease, but not with small-bowel disease. CONCLUSIONS: In this description of a genotype/phenotype correlation in CD patients and NOD2 variants, data suggest that variation in this gene contributes to the occurrence of fibrostenotic CD of the small bowel.

6-MP metabolite profiles provide a biochemical explanation for 6-MP resistance in patients with inflammatory bowel disease.

BACKGROUND & AIMS: Approximately 40% of inflammatory bowel disease (IBD) patients fail to benefit from 6-mercaptopurine (6-MP)/azathioprine (AZA). Recent reports suggest 6-thioguanine nucleotide (6-TGN) levels (>235) independently correlate with remission. An inverse correlation between 6-TGN and thiopurine methyltransferase (TPMT) has been described. The objectives of this study were to determine whether dose escalation optimizes both 6-TGN levels and efficacy in patients failing therapy because of subtherapeutic 6-TGN levels and its effect on TPMT. METHODS: Therapeutic efficacy and adverse events were recorded at baseline and upon reevaluation after dose escalation in 51 IBD patients. 6-MP metabolite levels and TPMT activity were recorded blinded to clinical information. RESULTS: Fourteen of 51 failing 6-MP/AZA at baseline achieved remission upon dose escalation, which coincided with significant rises in 6-TGN levels. Despite increased 6-MP/AZA doses, 37 continued to fail therapy at follow-up. Dose escalation resulted in minor changes in 6-TGN, yet a significant increase in 6-methylmercaptopurine ribonucleotides (6-MMPR) (P < or = 0.01) and 6-MMPR:6-TGN ratio (P < 0.001). 6-MMPR rises were associated with dose-dependent hepatotoxicity in 12 patients (24%). TPMT was not influenced by dose escalation. CONCLUSIONS: Serial metabolite monitoring identifies a novel phenotype of IBD patients resistant to 6-MP/AZA therapy biochemically characterized by suboptimal 6-TGN and preferential 6-MMPR production upon dose escalation.