Usefulness of fecal calprotectin by monoclonal antibody testing in adult Japanese with inflammatory bowel diseases: a prospective multicenter study

BACKGROUND/AIMS: Noninvasive objective monitoring is advantageous for optimizing treatment strategies in patients inflammatory bowel disease (IBD). Fecal calprotectin (FCP) is superior to traditional biomarkers in terms of assessing the activity in patients with IBD. However, there are the differences among several FCP assays in the dynamics of FCP. In this prospective multicenter trial, we investigated the usefulness of FCP measurements in adult Japanese patients with IBD by reliable enzyme immunoassay using a monoclonal antibody. METHODS: We assessed the relationship between FCP levels and disease or endoscopic activity in patients with ulcerative colitis (UC, n=64) or Crohn’s disease (CD, n=46) compared with healthy controls (HCs, n=64). RESULTS: FCP levels in UC patients strongly correlated with the Disease Activity Index (rs =0.676, P < 0.0001) and Mayo endoscopic subscore (MES; rs =0.677, P < 0.0001). FCP levels were significantly higher even in patients with inactive UC or CD compared with HCs (P=0.0068, P < 0.0001). The optimal cutoff value between MES 1 and 2 exhibited higher sensitivity (94.1%). FCP levels were significantly higher in active UC patients than in inactive patients (P < 0.001), except those with proctitis. The Crohn’s Disease Activity Index tended to correlate with the FCP level (rs =0.283, P=0.0565). CONCLUSIONS: Our testing method using a monoclonal antibody for FCP was well-validated and differentiated IBD patients from HCs. FCP may be a useful biomarker for objective assessment of disease activity in adult Japanese IBD patients, especially those with UC.

NUDT15, FTO, and RUNX1 genetic variants and thiopurine intolerance among Japanese patients with inflammatory bowel diseases

BACKGROUND/AIMS: Recent genome-wide analyses have provided strong evidence concerning adverse events caused by thiopurine drugs such as azathioprine (AZA) and 6-mercaptopurine. The strong associations identified between NUDT15 p.Arg139Cys and thiopurine-induced leukopenia and severe hair loss have been studied and confirmed over the last 2 years. However, other coding variants, including NUDT15 p.Val18_Val19insGlyVal, NUDT15 p.Val18Ile, and FTO p.Ala134Thr, and a noncoding variation in RUNX1 (rs2834826) remain to be examined in detail in this respect. Therefore, we investigated the correlation between these adverse events and the 5 recently identified variants mentioned above among Japanese patients with inflammatory bowel diseases (IBD). METHODS: One hundred sixty thiopurine-treated patients with IBD were enrolled. Genotyping was performed using TaqMan SNP Genotyping Assays or Sanger sequencing. RESULTS: None of the 5 variants were associated with gastrointestinal intolerance to AZA. However, NUDT15 p.Arg139Cys was significantly associated with the interval between initiation and discontinuation of AZA among patients with gastrointestinal intolerance. This variant was strongly associated with early (<8 weeks) and late (≥8 weeks) leukopenia and severe hair loss. Moreover, it correlated with the interval between initiation of thiopurine therapy and leukopenia occurrence, and average thiopurine dose. NUDT15 p.Val18_Val19insGlyVal, NUDT15 p.Val18Ile, FTO p.Ala134Thr, and RUNX1 rs2834826 exhibited no significant relationship with the adverse events examined. CONCLUSIONS: Of the 5 variants investigated, NUDT15 p.Arg139Cys had the strongest impact on thiopurine-induced leukopenia and severe hair loss; therefore, its genotyping should be prioritized over that of other variants in efforts to predict these adverse events in Japanese patients with IBD.

Infliximab Therapy Impacts the Peripheral Immune System of Immunomodulator and Corticosteroid Naive Patients with Crohn's Disease

BACKGROUND/AIMS: Infliximab (IFX), an antibody to tumor necrosis factor, (TNF)-alpha has efficacy in treating Crohn's disease (CD). However, knowledge of the potential effects of IFX on patients' immune profiles is lacking. The purpose of this study was to reveal the immunological effects of IFX. METHODS: Twenty-two patients with a CD activity index (CDAI) of 194.2+/-92.9 and an average duration of disease of 3.26 months and 21 healthy controls were included. Patients were to have their first IFX remission induction therapy with 3 infusions (5 mg/kg) at weeks 0, 2, and 6. Oral 5-aminosalicylic acid was the only ongoing medication in the patient population. Blood samples at baseline, 12 hours after the first infusion and at week 14 were labeled with anti-CD4/CD25 antibodies for immunohistochemical measurement of regulatory T-cells (Treg). Serum cytokines and chemokines were measured by suspension array and ELISA. RESULTS: CDAI significantly decreased prior to the second IFX infusion (p<0.001). Clinical remission rates were 77.3% and 91% by the second and third infusions, respectively. At baseline, interleukin (IL)-6 (p<0.03), IL-8 (p<0.03), IL-10 (p=0.050), IL-13 (p<0.01), transforming growth factor-beta1 (p<0.01), and 'regulated on activation, normal T cell expressed and secreted' (RANTES) (p<0.01) were elevated in patients. After the initial IFX infusion, TNF-alpha (p<0.04), IL-6 (p<0.03), interferon (IFN)-gamma (p<0.04), IFN-gamma-inducible protein-10 (p<0.01), monocyte chemoattractant protein-1 (p<0.01), macrophage inflammatory protein-1beta (p<0.01), and RANTES (p<0.01) were decreased. IFX infusion was associated with an increase in Treg (p<0.01) and a decrease in the Th1 (IFN-gamma)/Th2 (IL-4) ratio (p<0.03). CONCLUSIONS: IFX use was associated with restoration of the Th1/Th2 balance after a single infusion and seemed to promote induction of naive Th0 lymphocytes to Treg. This knowledge should have clinical relevance.