Naho Obayashi

Comparison of Gene Expression Between Pediatric and Adult Gastric Mucosa with Helicobacter pylori Infection

Although Helicobacter pylori infection among adults is a major risk factor for the development of gastric cancer and initial infection with H. pylori may occur before 5 years of age, the direct effects of H. pylori infection since childhood on gastric mucosa are unknown. The aim of this study was to evaluate gene expression in the H. pylori‐infected gastric mucosa of children.

Microarray analysis of gastric mucosa among children with Helicobacter pylori infection.

Background:  Although initial infection with Helicobacter pylori may occur before 5 years of age, the pediatric mucosal immune response against H. pylori is not clear. The aim of the present study was to evaluate immune responses in the H. pylori‐infected gastric mucosa of children using microarray and real‐time polymerase chain reaction (PCR) analysis of pediatric gastric samples.

Leopard Skin-Like Colonic Mucosa: A Novel Endoscopic Finding of Chronic Granulomatous Disease-Associated Colitis.

Background: Chronic granulomatous disease (CGD) is a rare inherited disorder in which phagocytes are unable to eradicate pathogens because of a deficit of nicotinamide adenine dinucleotide phosphate oxidase. Among CGD patients, ∼30% to 50% develop severe gastrointestinal tract symptoms. Although characteristic histologic findings of CGD-associated colitis have been reported, information on endoscopic features remained vague. Methods: A total of 8 male patients with CGD (ages 2–23 years) from 2 Japanese institutions underwent colonoscopy for the evaluation of their fever, diarrhea, bloody stool, and abdominal pain. The endoscopic and histologic findings were retrospectively reviewed. Results: The endoscopic findings of CGD-associated colitis appeared varied. Notably, brownish dots over a yellowish edematous mucosa were observed in 3 of the 8 patients. Prominent pigment-laden macrophages were noted histologically on the mucosa. Conclusions: Although nonspecific endoscopic findings of CGD-associated colitis have been reported before, our observation of brownish dots spread across a yellowish edematous mucosa, termed “leopard sign,” could be a unique feature of this condition.

Validation of predictive equations for resting energy expenditure in Japanese pediatric Crohn's disease patients: preliminary study.

Predictive equations are often used to estimate resting energy expenditure (REE). Determining the appropriate equation for different patient types, however, remains inconclusive, as in the case of Japanese children with Crohns disease (CD). The aim of this study was to identify an appropriate predictive equation for measuring REE in Japanese children with CD.

Romiplostim treatment allows for platelet transfusion-free liver transplantation in pediatric thrombocytopenic patient with primary sclerosing cholangitis

Thrombocytopenia is a major risk factor for cirrhotic liver disease. Patients with thrombocytopenia may have esophageal or gastric varices secondary to portal hypertension, leading to variceal bleeding which exposes the liver to further damage. Here, we present a female pediatric patient with PSC and CD, whose progressive thrombocytopenia was successfully controlled by romiplostim, a TPO receptor agonist. The patient developed bloody diarrhea at four yr of age, and was subsequently diagnosed with PSC and CD when seven yr old. While CD was well‐controlled by immunomodulators, the patients thrombocytopenia gradually progressed resulting in petechiae (platelet count of 11 × 109/L) when she was 10 yr and four months old. She responded poorly to immunoglobulin and corticosteroids. Weekly subcutaneous injection of romiplostim was therefore initiated, and platelet counts were maintained over at 50 × 109/L. She was able to undergo successful LDLT without platelet transfusion seven months after the initiation of romiplostim. Romiplostim was not required after LDLT with improved platelet counts. This case report suggests that romiplostim may be effective in the treatment of thrombocytopenic children with liver cirrhosis and portal hypertension, and in eliminating the need for platelet transfusion during the peri‐transplant period.

Host response genes associated with nodular gastritis in Helicobacter pylori infection

Chronic Helicobacter pylori infection in children induces lymphoid hyperplasia called nodular gastritis (NG) at the antral gastric mucosa. The aim of this study was to evaluate genes in gastric biopsy on microarray analysis, to identify molecules associated with NG on comparison with NG‐negative pediatric corpus tissue and with H. pylori‐infected adult tissue with atrophic gastritis (AG).

Management of tacrolimus-associated food allergy after liver transplantation

Increasingly, food allergy associated with tacrolimus after pediatric living‐donor liver transplantation (LT) has been reported. Tacrolimus prevents the activation of T cells by blocking calcineurin, thus producing an immunosuppressive effect, but tacrolimus induces an imbalance in T‐helper type 1 (Th1) and Th2 cells in the food allergy process. This report describes a case of tacrolimus‐associated food allergy after pediatric living‐donor LT. The patient was a 7‐year‐old Japanese girl who had undergone living‐donor LT at 12 months of age, and whom we first saw in the clinic at age 18 months. She received immunosuppressive therapy by tacrolimus after transplantation. Atopic dermatitis developed in post‐transplant month 18. Stridor, facial edema, lip swelling, and skin erythema after consuming tempura udon containing wheat occurred in post‐transplant month 39, and she was subsequently diagnosed with anaphylactic shock. Eosinophilic leukocyte and serum immunoglobulin (Ig)E increased, and specific IgE was positive for some food allergens. Pharmacotherapy was therefore changed from tacrolimus to cyclosporine A, after which eosinophilic leukocyte and serum IgE decreased and atopic dermatitis improved.