Enhanced differentiation of intraepithelial lymphocytes in the intestine of polymeric immunoglobulin receptor-deficient mice.

To clarify the effect of secretory IgA (sIgA) deficiency on gut homeostasis, we examined intraepithelial lymphocytes (IELs) in the small intestine (SI) of polymeric immunoglobulin receptor-deficient (pIgR(-/-) ) mice. The pIgR(-/-) mice exhibited the accumulation of CD8αß(+) T-cell receptor (TCR)-αß(+) IELs (CD8αß(+) αß-IELs) after weaning, but no increase of CD8αß(+) γδ-IELs was detected in pIgR(-/-) TCR-ß(-/-) mice compared with pIgR(+/+) TCR-ß(-/-) mice. When 5-bromo-2'-deoxyuridine (BrdU) was given for 14 days, the proportion of BrdU-labelled cells in SI-IELs was not different between pIgR(+/+) mice and pIgR(-/-) mice. However, the proportion of BrdU-labelled CD8αß(+) -IELs became higher in pIgR(-/-) mice than pIgR(+/+) mice 10 days after discontinuing BrdU-labelling. Intravenously transferred splenic T cells migrated into the intraepithelial compartments of pIgR(+/+) TCR-ß(-/-) mice and pIgR(-/-) TCR-ß(-/-) mice to a similar extent. In contrast, in the case of injection of immature bone marrow cells, CD8αß(+) αß-IELs increased much more in the SI of pIgR(-/-) TCR-ß(-/-) mice than pIgR(+/+) TCR-ß(-/-) mice 8 weeks after the transfer. αß-IELs from pIgR(-/-) mice could produce more interferon-γ and interleukin-17 than those of pIgR(+/+) mice, and intestinal permeability tended to increase in the SI of pIgR(-/-) mice with aging. Taken together, these results indicate that activated CD8αß(+) αß-IELs preferentially accumulate in pIgR(-/-) mice through the enhanced differentiation of immature haematopoietic precursor cells, which may subsequently result in the disruption of epithelial integrity.

ω-3 fatty acids attenuate mucosal inflammation in premature rat pups.

BACKGROUND: Necrotizing enterocolitis (NEC) is a devastating intestinal disease of premature infants. Although ω-3 fatty acids are known to have antiinflammatory effects, their effect against NEC remains unclear. METHODS: Mother rats fed a soybean-based, docosahexaenoic acid (DHA)- or eicosapentaenoic acid (EPA)-enriched diet from days 7 to 20 of gestation were examined. On day 20, the rat pups were delivered by abdominal incision, their intestines were removed, and messenger RNA was extracted. A rat NEC model was used to confirm the effects of ω-3 fatty acids on the inflamed intestine (n = 20-28). The expression of inflammatory molecules was analyzed by real-time polymerase chain reaction (n = 11-14). RESULTS: The concentrations of DHA and EPA in the intestine were significantly increased in the DHA and EPA groups (P < .01). The expression of the antiinflammatory prostaglandin E2 receptor EP3 was increased in the DHA (P < .05) and EPA groups (P < .01). In the NEC model, the reduced incidence of colitis was confirmed in the DHA and EPA groups. The expression of peroxisome proliferator-activated receptor γ was increased (P < .05), and the inhibitor of nuclear factor-κB α/ß decreased in both the DHA (P < .01) and EPA groups (P < .05). CONCLUSION: Our findings indicate that ω-3 fatty acids are beneficial for protecting the premature intestine from inflammation by regulating eicosanoid- and nuclear factor-κB-related metabolite expression.

Monitoring 6-thioguanine nucleotide concentrations in Japanese children and adolescents with inflammatory bowel disease.

BACKGROUND AND AIM: 6-Mercaptopurine (6-MP) and azathioprine (AZA) are widely used as maintenance therapy in children with inflammatory bowel disease (IBD). However, proper 6-thioguanine nucleotide (6-TGN) concentrations in Japanese children with IBD have not been reported. METHODS: This retrospective review examines 32 ulcerative colitis (UC) patients and 19 Crohn's disease (CD) patients (12.87 ± 3.56 years) who required 6-MP or AZA to maintain disease remission. All patients were treated with 6-MP or AZA for at least 3 weeks prior to this study in addition to previous treatment. 6-MP dose, 6-TGN levels, assayed by high-performance liquid chromatography, as well as laboratory data were evaluated. RESULTS: Thirty-five children were successfully kept in remission with 6-MP and AZA therapy after weaning off corticosteroids. Overall, 123 measurements (59 active disease, 64 in remission) were analyzed. The mean 6-TGN concentration of the entire study population was 499.61 ± 249.35 pmol/8 × 10(8) red blood cell. The mean 6-MP dose in patients with active disease (0.910 ± 0.326 mg/kg per day) was significantly higher than for patients in remission (0.749 ± 0.225) (P = 0.0016). A significant inverse correlation was found between white blood cell counts and 6-TGN concentrations (r = 0.275, P < 0.002). Two patients experienced leukopenia with alopecia, and four transiently experienced increased serum levels of pancreatic enzymes, although no thiopurine S-methyl transferase mutations were confirmed. CONCLUSION: The doses of 6-MP or AZA needed to maintain remission in Japanese children with IBD are lower than those reported in Western countries. However, 6-TGN concentrations in this population are higher than previously reported.

Increased mucosal expression of GATA-3 and STAT-4 in pediatric ulcerative colitis.

BACKGROUND: Serum pro-inflammatory cytokine levels are frequently elevated in the acute phase of pediatric inflammatory bowel disease (IBD). Because the role of pro-inflammatory cytokine in the acute phase of pediatric IBD has not been well investigated, the serum levels of pro-inflammatory cytokines and the expression of Th1 and Th2 signaling molecules in mucosa from the acute phase of pediatric IBD were examined. METHODS: Twenty children with ulcerative colitis (UC; mean age, 9.95 ± 4.10 years) and 12 with Crohn's disease (CD; mean age, 10.0 ± 4.90 years) were enrolled for the serum cytokine (interleukin [IL]-4, IL-5, IL-6, tumor necrosis factor-α, tumor growth factor-ß1, and interferon-γ) assay. Expression of T-helper cell 1 (Th1) (T-box expressed in T cells: T-bet and signal transducer and activator of transcription-4: STAT-4) and Th2 (GATA-3 and STAT-6) signaling molecules was examined on real-time polymerase chain reaction using mucosal samples from eight children in the acute phase of UC, eight with CD and eight controls. RESULTS: Significant elevation of serum IL-4 and IL-6 levels was detected at the acute phase of pediatric UC and CD compared with levels at remission (P < 0.05 in each). The mucosal expression of GATA-3 and STAT-4 was significantly enhanced in the acute phase of pediatric UC compared with normal mucosa. No significant difference was observed in the expression of all examined molecules in the acute phase of pediatric CD. CONCLUSIONS: IL-4 and its signaling molecule GATA-3, as well as the Th1 signaling molecule STAT-4, are involved in the pathogenesis of acute phase of pediatric UC.

Acute encephalopathy with biphasic seizures and late reduced diffusion associated with hemophagocytic syndrome.

We reported a girl with HHV-6 infection associated with both acute encephalopathy with biphasic seizures and late reduced diffusion, and hemophagocytic syndrome. She had a prolonged convulsion after a one-day history of febrile illness. Cerebrospinal fluid or brain CT showed no abnormalities on admission and her consciousness was recovered on the next day. However, a prolonged seizure and deterioration of consciousness appeared on the sixth day of illness. Diffusion-weighted images revealed marked reduction of water diffusion in the bilateral frontal areas. HHV-6 infection was virologically proven by polymerase chain reaction. She was treated with gamma-globulin, steroid pulse therapy, and brain hypothermia. In addition, decrease in white blood cells and platelet counts, and elevation of liver enzymes and ferritin were noted on the fourth day of illness. Hemophagocytic macrophages were revealed by bone marrow aspiration on the sixth day. Her hematological and blood chemistry abnormalities recovered gradually after steroid pulse therapy. An elevation of interleukin-6, -8, and -10, and tumor necrosis factor in the serum and that of interleukin-4, -6, and-8 in the cerebrospinal fluid were observed at the onset of a late seizure. These facts suggested that hypercytokinemia will be related to the pathogenesis of acute encephalopathy of our patient.