Retrospective cohort study of methotrexate use in the treatment of pediatric Crohn's disease.

BACKGROUND: Methotrexate (MTX) use as an alternative to thiopurines in the treatment of Crohn's disease (CD) in children is increasing. This study was undertaken to assess safety and efficacy of MTX in children with CD. METHODS: Patients treated with MTX with a minimum of 1-year follow-up were identified in the Pediatric IBD Collaborative Research Group Registry, a prospective inception cohort study started in 2002. The clinical efficacy and safety of MTX were analyzed retrospectively. RESULTS: Two hundred ninety patients treated with MTX were identified. One hundred seventy-two patients received at least 3 months of MTX without thiopurine or biologicals and had ≥1 year of follow-up. Eighty-one of 172 patients (47%) received MTX as first immunomodulator (IMM), of which 22 (27%) achieved ≥12 months of sustained clinical remission without surgery, thiopurine, biologicals, or corticosteroids. Those receiving MTX as second IMM achieved similar remission rate (35%, P = not significant). Fourteen percent received MTX as first IMM in 2002 and 60% in 2010 (P = 0.005). Disease location did not affect outcomes. MTX doses were equivalent in both groups. Fifteen percent of patients developed an alanine aminotransferase >60 international units/liter and 12% developed a white blood cell <4000 cells per microliter while on MTX. Only 4% of these discontinued MTX completely. A small group of 6 centers, which contributed only about one-third of patients with CD in the registry, contributed nearly two-thirds of the patients receiving MTX (P < 0.001). CONCLUSIONS: MTX use as first choice IMM is increasing in pediatric CD. MTX provided sustained clinical remission in nearly one-third of patients with minimal toxicity. There is large center-to-center variability in its use.

Liver enzyme elevations within 3 months of diagnosis of inflammatory bowel disease and likelihood of liver disease.

BACKGROUND: Inflammatory bowel disease-associated liver diseases (IBD-LDs) include autoimmune hepatitis (AIH), primary sclerosing cholangitis (PSC), and an overlap syndrome. Prospective unbiased multicenter data regarding the frequency of IBD-LD in patients with pediatric inflammatory bowel disease (IBD) are lacking. We examined early alanine aminotransferase (ALT) and γ-glutamyl transpeptidase (GGT) elevations in children diagnosed as having IBD and assessed the likelihood of IBD-LD. METHODS: Data collected from the prospective observational Pediatric Inflammatory Bowel Disease Collaborative Research Group Registry enrolling children of age <16 years within 30 days of diagnosis. AIH, PSC, and overlap syndrome were diagnosed using local institutional criteria. RESULTS: A total of 1569 subjects had liver enzymes available. Of the total, 757 had both ALT and GGT, 800 had ALT only (no GGT), and 12 had GGT only (no ALT). Overall, 29 of 1569 patients (1.8%) had IBD-LD. IBD-LD was diagnosed in 1 of 661 (0.15%) of patients with both ALT and GGT ≤ 50 IU/L compared with 21 of 42 (50%) of patients with both ALT and GGT > 50 (odds ratio 660, P < 0.0001). Of the 29 patients with IBD-LD, 21 had PSC, 2 had AIH, and 6 had overlap syndrome. IBD-LD was more common in patients with ulcerative colitis and IBD-unclassified (indeterminate colitis) than in those with Crohn disease (4% vs 0.8%, respectively, P < 0.001). CONCLUSIONS: Elevation of both ALT and GGT within 90 days after the diagnosis of IBD is associated with a markedly increased likelihood of IBD-LD. Both ALT and GGT levels should be measured in all of the pediatric patients newly diagnosed as having IBD.

Ret heterozygous mice have enhanced intestinal adaptation after massive small bowel resection.

Intestinal adaptation is an important compensatory response to massive small bowel resection (SBR) and occurs because of a proliferative stimulus to crypt enterocytes by poorly understood mechanisms. Recent studies suggest the enteric nervous system (ENS) influences enterocyte proliferation. We, therefore, sought to determine whether ENS dysfunction alters resection-induced adaptation responses. Ret+/- mice with abnormal ENS function and wild-type (WT) littermates underwent sham surgery or 50% SBR. After 7 days, ileal morphology, enterocyte proliferation, apoptosis, and selected signaling proteins were characterized. Crypt depth and villus height were equivalent at baseline in WT and Ret+/- mice. In contrast after SBR, Ret+/- mice had longer villi (Ret+/- 426.7 ± 46.0 µm vs. WT 306.5 ± 7.7 µm, P < 0.001) and deeper crypts (Ret+/- 119 ± 3.4 µm vs. WT 82.4 ± 3.1 µm, P < 0.001) than WT. Crypt enterocyte proliferation was higher in Ret+/- (48.8 ± 1.3%) than WT (39.9 ± 2.1%; P < 0.001) after resection, but apoptosis rates were similar. Remnant bowel of Ret+/- mice also had higher levels of glucagon-like peptide 2 (6.2-fold, P = 0.005) and amphiregulin (4.6-fold, P < 0.001) mRNA after SBR, but serum glucagon-like peptide 2 protein levels were equal in WT and Ret+/- mice, and there was no evidence of increased c-Fos nuclear localization in submucosal neurons. Western blot confirmed higher crypt epidermal growth factor receptor (EGFR) protein levels (1.44-fold; P < 0.001) and more phosphorylated EGFR (2-fold; P = 0.003) in Ret+/- than WT mice after SBR. These data suggest that Ret heterozygosity enhances intestinal adaptation after massive SBR, likely via enhanced EGFR signaling. Reducing Ret activity or altering ENS function may provide a novel strategy to enhance adaptation attenuating morbidity in patients with short bowel syndrome.