Hiroyuki Hanai

CYP2C19 genotype status and effect of omeprazole on intragastric pH in humans

Omeprazole is metabolized by genetically determined S‐mephenytoin 4′‐hydroxylase (CYP2C19) in the liver. This study aimed to determine whether the effect of omeprazole on intragastric pH depends on CYP2C19 genotype status.

Adacolumn, an adsorptive carrier based granulocyte and monocyte apheresis device for the treatment of inflammatory and refractory diseases associated with leukocytes

Abstract:  Apheresis has been recognized both economically and therapeuticallyas a novel approach for the treatment of inflammatory diseases,and certain others, which respond poorly to drug therapy. This reportis about Adacolumn, an adsorptive carrier based granulocyteand monocyte apheresis device with a volume of 335 mL,filled with about 220 g of cellulose acetate beads of 2 mmdiameter as the column adsorptive carriers. Pre‐ and post‐columnleukocyte counts have shown that the carriers adsorb about 65% ofgranulocytes, 55% of monocytes and 2% of lymphocytesfrom the blood in the column. Additionally, after apheresis, thereis a marked decrease in inflammatory cytokines (TNF‐α,IL‐1β, IL‐6 and IL‐8) produced by blood leukocytes,together with down‐modulation of l‐selectinand the chemokine receptor CXCR3. Adacolumn has been used to treatpatients with rheumatoid arthritis, ulcerative colitis and HIV infection. Typicalapheresis sessions have been 4–10, at a frequency of oneor two sessions per week. Treatment of patients with Adacolumn hasbeen associated with very promising efficacy and safety data. Accordingly,in Japan, Adacolumn has been approved by the Ministry of Healthfor the treatment of ulcerative colitis. Furthermore, Adacolumnmet the required quality and safety standards for medical devices andreceived an EC certification (CE‐mark) from TUV in 1999. However,although Adacolumn carriers are very efficient in depleting excessand activated granulocytes and monocytes/macrophages, theclinical efficacy associated with Adacolumn apheresis cannot befully explained on the basis of reducing granulocytes and monocytesper se. Hence, a long lasting effect on inflammatory cytokine generation,chemokine activities or immunomodulation is likely, but the precisemechanisms involved are not fully understood yet.

Effects of CYP2C19 genotypic differences in the metabolism of omeprazole and rabeprazole on intragastric pH

Omeprazole is mainly metabolized in the liver by CYP2C19, a genetically determined enzyme, whereas rabeprazole is mainly reduced non‐enzymatically and partially metabolized by CYP2C19. The therapeutic effects of rabeprazole are therefore assumed to be less affected by an individual’s CYP2C19 status.

Effect of cytochrome P4502C19 genotypic differences on cure rates for gastroesophageal reflux disease by lansoprazole

The acid‐inhibitory effect of lansoprazole depends on differences in cytochrome P450 (CYP) 2C19 genotypes. We assessed whether therapeutic effects of lansoprazole on gastroesophageal reflux disease (GERD) depended on the CYP2C19 genotype status in relation to the grade of GERD.

Effects of Helicobacter pylori infection on gastric acid secretion and serum gastrin levels in Mongolian gerbils

BACKGROUND AND AIMS Body gastritis caused by Helicobacter pylori infection appears to inhibit gastric acid secretion. The aim of this study was to determine the effects ofH pylori infection on gastric acid secretion and clarify its mechanisms with reference to interleukin 1β (IL-1β). METHODS (1) Mongolian gerbils were inoculated orally with H pylori. Before, six, and 12 weeks after inoculation, serum gastrin levels, gastric acid output, and IL-1β mRNA levels in the gastric mucosa were determined. Pathological changes were also determined according to the updated Sydney system. (2) Effects of recombinant human IL-1 receptor antagonist (rhIL-1ra) on gastric acid output and serum gastrin levels were also determined. RESULTS (1) Scores for activity and inflammation of gastritis and serum gastrin levels were significantly increased, and gastric acid output was significantly decreased six and 12 weeks after inoculation withH pylori. IL-1β mRNA levels in the gastric mucosa were also elevated six and 12 weeks after inoculation withH pylori. (2) Acid output and serum gastrin levels in the infected groups returned to control levels after rhIL-1ra injection. CONCLUSIONS Gastric acid secretion is decreased and serum gastrin levels are increased in Mongolian gerbils infected with H pylori. This change in gastric acid secretion appears to be mediated by IL-1β induced by H pylori infection.

Effects of genotypic differences in CYP2C19 status on cure rates for Helicobacter pylori infection by dual therapy with rabeprazole plus amoxicillin.

Rabeprazole is a potent proton pump inhibitor and is mainly reduced to thioether rabeprazole by a non-enzymatic pathway and partially metabolized to demethylated rabeprazole by CYP2C19 in the liver. We intended to determine a cure rate for Helicobacter pylori infection by dual rabeprazole/amoxicillin therapy in relation to CYP2C19 genotype status prospectively. Ninety-seven patients with gastritis and H. pylori infection completed the dual therapy with 10 mg of rabeprazole bid and 500 mg of amoxicillin tid for 2 weeks. At 1 month after treatment, cure of H. pylori infection was assessed on the basis of histology, a rapid urease test, culture, polymerase chain reaction (PCR), and 13C-urea breath test. CYP2C19 genotype status was determined by a PCR-restriction fragment length polymorphism method. Of the 97 patients, 33 were homozygous extensive metabolizers (homEM), 48 were heterozygous extensive metabolizers (hetEM), and 16 were poor metabolizers (PM). Cure of H. pylori infection was achieved in 79 of the 97 patients (81.4%, 95%CI = 71.9-88.7). Significant differences in cure rates among the homEM, hetEM, and PM groups were observed; 60.6% (95%CI = 42.1-77.3), 91.7% (95%CI = 80.0-97.7), and 93.8% (95%CI = 69.8-99.8), respectively (P = 0.0007). Twelve patients without cure after initial treatment (10 homEMs and 2 hetEMs) were successfully retreated with rabeprazole 10 mg q.i.d. and amoxicillin 500 mg q.i.d. for 2 weeks. The cure rates for H. pylori infection by dual rabeprazole/amoxicillin therapy depended on the CYP2C19 genotype status. This dual therapy appears to be effective for hetEM and PM patients. However, high dose dual rabeprazole/amoxicillin therapy was effective even for homEM patients. Therefore, the genotyping test of CYP2C19 appears to be a clinically useful tool for the optimal dual treatment with rabeprazole plus amoxicillin.

Adsorptive Granulocyte and Monocyte Apheresis versus Prednisolone in Patients with Corticosteroid-Dependent Moderately Severe Ulcerative Colitis

Background/Aim: Active ulcerative colitis (UC) is often associated with increased peripheral granulocytes and monocytes/macrophages which show activation behavior and prolonged survival time. Further, mucosal granulocyte level parallels intestinal inflammation and can predict UC relapse. Accordingly, our aim was to see if adsorptive granulocyte/monocyte apheresis (GMA) can promote remission and spare steroid in patients with steroid-dependent (SD) UC. Methods: 69 SD patients, at the time of relapse, were randomly assigned to groups I (n = 46) and II (n = 23). The mean dose of prednisolone (PSL) was 12 mg/day/patient, CAI (clinical activity index) 9.2 in both groups. Group I patients were given up to 11 GMA sessions over 10 weeks with Adacolumn; in group II, the mean dose of PSL was increased to 30 mg/day/patient. Results: At week 12, 83% of group I and 65% of group II patients were in remission, CAI in group I was 1.7 (p < 0.001) and in group II, 2.5 (p < 0.001). Further, during the 12 weeks of treatment, the cumulative amount of PSL received per patient was 1,157 mg in group I and 1,938 mg in group II (p = 0.001). Conclusions: GMA appeared to be an effective adjunct to standard drug therapy of moderately severe UC by promoting remission and sparing steroids.

alphaPIX nucleotide exchange factor is activated by interaction with phosphatidylinositol 3-kinase.

p21-activated kinase (PAK) is a common effector protein of the small GTPases Cdc42 and Rac, leading to the activation of downstream mitogen activated protein kinases. PAK also mediates polarized cytoskeletal changes induced by these GTPases. The recently identified PAK-interacting exchange factor (PIX) acts as a guanine nucleotide exchange factor on Rac, and colocalizes with PAK in a focal complex, but little is known about the associated signaling cascades, including upstream activators of PIX. In this study, we show that one of the isoforms of PIX, αPIX, is activated by signaling cascades from the platelet-derived growth factor (PDGF) receptor and EphB2 receptor, and from integrin-induced signaling through phosphatidylinositol 3-kinase (PI3-kinase). αPIX is activated by forming a complex with these receptors either via association with PAK and Nck, or direct association with the p85 regulatory subunit of PI3-kinase. Synthetic phosphoinositide and membrane targeted PI3-kinase augmented the αPIX activity in vivo. In Xenopus, aggregates of mesodermal cells derived from embryos microinjected with αPIX significantly increased the peripheral spreading on fibronectin substrate in response to PDGF through PI3-kinase. These results indicate that αPIX is activated by PI3-kinase, and is involved in the receptor mediated signaling leading to the activation of the kinase activity of PAK, and the migration of mesodermal cells on extracellular matrix.

Relationship Between Fecal Calprotectin, Intestinal Inflammation, and Peripheral Blood Neutrophils in Patients with Active Ulcerative Colitis

Active ulcerative colitis (UC) is associated with elevated granulocytes and monocytes/macrophages (GM) which show activation behavior and increased survival time. Further, fecal calprotectin (a stable neutrophil protein) level parallels intestinal inflammation and can predict UC relapse. Since GM are major sources of inflammatory cytokines and chemokines, they are suspected to have roles in the initiation and perpetuation of UC. Our objective was to investigated relationships between peripheral blood (PB) neutrophils, calprotectin, and UC disease activity. Full PB and calprotectin were determined in 69 healthy controls and 31 patients with UC, then 7 randomly selected patients received GM adsorptive apheresis (GMA) with Adacolumn, 10 sessions of 60-min duration each. Patients with UC had higher neutrophil counts (P<0.001), but lower lymphocyte counts (P<0.001) compared with controls. Further, fecal calprotectin levels showed a correlation with UC clinical activity index (CAI; P<0.001) and mucosal inflammation (P<0.001). Following GMA, there were falls in neutrophils (P<0.02), CAI (P<0.02) and calprotectin (P<0.02). In conclusion, GM appear to contribute to intestinal inflammation and UC activity and reduction of these cells by GMA should benefit patients with active UC. Further, the correlations among calprotectin, UC activities, and PB neutrophils should serve as the basis for preemptive actions to control this disease.

Adsorptive depletion of elevated proinflammatory CD14+CD16+DR++ monocytes in patients with inflammatory bowel disease.

BACKGROUND:In human blood, two monocyte populations exist, CD14++CD16− classical monocytes and CD14+CD16+ proinflammatory monocytes, which account for about 10% of total monocytes, but can expand to promote inflammatory conditions. CD14+CD16+ monocytes produce large amounts of inflammatory cytokines including TNF-α and IL-1. Adacolumn adsorptive carriers adsorb from the blood in the column most of the monocytes/macrophages and granulocytes and this has been associated with clinical efficacy in patients with active inflammatory bowel disease (IBD). This study was to investigate the CD14+CD16+ monocyte profile in patients with IBD and the impact of Adacolumn on this proinflammatory phenotype.METHODS:A total of 58 patients with ulcerative colitis (UC, N = 37) or Crohns disease (CD, N = 21) together with 11 healthy controls were included in this study. Peripheral blood CD14+CD16+ monocytes were determined by three-color immunofluorescence and flow cytometry.RESULTS:The percentage of CD14+CD16+ monocytes in patients with active CD was significantly (P = 0.0089) higher than the level in the control group, in patients with quiescent CD (P = 0.0419) or quiescent UC (P = 0.0063). Further, the percentage of CD14+CD16+ monocytes in patients with active UC who were on prednisolone (PSL) was less than the level in those not on PSL (P < 0.0001), thus PSL might have a suppressive effect on CD14+CD16+ monocytes. Patients with active IBD were each given up to 10 Adacolumn granulocye/monocyte adsorption (GMA) sessions over an 8-wk period. The percentage of CD14+CD16+ monocytes decreased dramatically (P = 0.0077 in UC and P = 0.0117 in CD) compared with entry levels.CONCLUSIONS:A significant reduction in peripheral CD14+CD16+ monocytes by GMA should mitigate the inflammatory drive and contribute to the clinical efficacy of this procedure. Reduction of CD14+CD16+ monocytes by corticosteroids was also seen. Hence, corticosteroids should enhance the efficacy of GMA. This is the first report on CD14+CD16+ monocytes being decreased by Adacolumn GMA in patients with IBD.