Interleukin-17 immunity in pediatric Crohn disease and ulcerative colitis.

OBJECTIVE: The present understanding of inflammatory bowel disease pathogenesis mainly relies on studies of adult patients. Therefore, we studied the balance between T-effector and regulatory cells in pediatric inflammatory bowel disease. METHODS: Quantitative polymerase chain reaction and immunohistochemistry served to quantify the expression of immunological markers in mucosal biopsies and flow cytometry analysis was used in peripheral blood mononuclear cells. RESULTS: Colonic interleukin (IL)-17+, IL-22, and IL-6 mRNA upregulation and increase in the number of colonic IL-17 cells were demonstrated in both Crohn disease (CD) and ulcerative colitis (UC). Likewise, colonic forkhead box P3 (FOXP3+) mRNA expression and the number of colonic FOXP3 cells were increased both in CD and in UC and were accompanied in CD also with increased numbers of FOXP3+CD25 High CD4 cells in peripheral blood. Ileal relation of IL-17/CD4 cells was increased only in CD. CONCLUSIONS: We showed activation of colonic IL-17/IL-22 axis and upregulation of FOXP3 to occur both in pediatric CD and in UC, indicating shared immunological characteristics. Upregulation of IL-17 was restricted to colon in UC, but existed in the ileum and in the colon in active CD.

Postoperative speech impairment and surgical approach to posterior fossa tumours in children: a prospective European multicentre cohort study.

BACKGROUND: Brain tumours are the most common solid tumours in childhood. Half of these tumours occur in the posterior fossa, where surgical removal is complicated by the risk of cerebellar mutism syndrome, of which postoperative speech impairment (POSI) is a cardinal symptom, in up to 25% of patients. The surgical approach to midline tumours, mostly undertaken by transvermian or telovelar routes, has been proposed to influence the risk of POSI. We aimed to investigate the risk of developing POSI, the time course of its resolution, and its association with surgical approach and other clinical factors. METHODS: In this observational prospective multicentre cohort study, we included children (aged <18 years) undergoing primary surgery for a posterior fossa tumour at 26 centres in nine European countries. Within 72 h of surgery, the operating neurosurgeon reported details on the tumour location, surgical approach used, duration of surgery, use of traction, and other predetermined factors, using a standardised surgical report form. At 2 weeks, 2 months, and 1 year after surgery, a follow-up questionnaire was filled out by a paediatrician or neurosurgeon, including neurological examination and assessment of speech. Speech was classified as mutism, reduced speech, or habitual speech. POSI was defined as either mutism or severely reduced speech. Ordinal logistic regression was used to analyse the risk of POSI. FINDINGS: Between Aug 11, 2014, and Aug 24, 2020, we recruited 500 children. 426 (85%) patients underwent primary tumour surgery and had data available for further analysis. 192 (45%) patients were female, 234 (55%) patients were male, 81 (19%) patients were aged 0-2 years, 129 (30%) were aged 3-6 years, and 216 (51%) were aged 7-17 years. 0f 376 with known postoperative speech status, 112 (30%) developed POSI, 53 (14%) developed mutism (median 1 day [IQR 0-2]; range 0-10 days), and 59 (16%) developed reduced speech after surgery (0 days [0-1]; 0-4 days). Mutually adjusted analyses indicated that the independent risk factors for development of POSI were younger age (linear spline, p=0·0087), tumour location (four levels, p=0·0010), and tumour histology (five levels, p=0·0030); surgical approach (six levels) was not a significant risk factor (p=0·091). Tumour location outside the fourth ventricle and brainstem had a lower risk of POSI (with fourth ventricle as reference, odds ratio (OR) for cerebellar vermis 0·34 [95% CI 0·14-0·77] and OR for cerebellar hemispheres 0·23 [0·07-0·70]). Compared with pilocytic or pilomyxoid astrocytoma, a higher risk of POSI was seen for medulloblastoma (OR 2·85 [1·47-5·60]) and atypical teratoid rhabdoid tumour (10·30 [2·10-54·45]). We did not find an increased risk of POSI for transvermian surgical approach compared with telovelar (0·89 [0·46-1·73]). Probability of speech improvement from mutism reached 50% around 16 days after mutism onset. INTERPRETATION: Our data suggest that a midline tumour location, younger age, and high-grade tumour histology all increase the risk of speech impairment after posterior fossa tumour surgery. We found no evidence to recommend a preference for telovelar over transvermian surgical approach in the management of posterior fossa tumours in children in relation to the risk of developing POSI. FUNDING: The Danish Childhood Cancer Foundation, the Swedish Childhood Cancer Foundation, the UK Brain Tumour Charity, the Danish Cancer Society, Det Kgl Kjøbenhavnske Skydeselskab og Danske Broderskab, the Danish Capitol Regions Research Fund, Dagmar Marshall Foundation, Rigshospitalet's Research Fund, and Brainstrust.

Infiltration of Foxp3- and Toll-like receptor-4-positive cells in the intestines of children with food allergy.

OBJECTIVES: Regulatory T (Treg) cells together with intestinal microflora play a central role in controlling allergic inflammation. We examined the markers related to Treg cells, and bacterial signaling, such as Toll-like receptors (TLR)-2 and -4, in the duodenal mucosa of patients with food allergy (FA). PATIENTS AND METHODS: Small intestinal samples were collected from patients with FA on a normal or an elimination diet, from healthy controls and patients with untreated celiac disease. Single and double immunohistochemistry were used to enumerate the densities of Foxp3-positive cells and TLR2- and TLR4-positive cells in the mucosa and evaluate the colocalization of Foxp3 expression in CD4, CD25, and CTLA-4 cells. The mRNA expression of CD25, Foxp3, TLR2, and TLR4 was measured by reverse transcriptase-polymerase chain reaction. RESULTS: The densities of Foxp3 and TLR4 cells were significantly increased in patients with untreated FA compared with healthy controls (P = 0.003, P = 0.033), and the Foxp3 cells were higher in untreated than in treated allergic patients (P < 0.001). The immense majority of Foxp3 cells were CD4 (median 100%), CTLA-4 (100%), or CD25 (81%). The ratio of Foxp3 mRNA to Foxp3 cells was decreased in patients with FA and in patients with celiac disease compared with controls (P = 0.036, P = 0.035). CONCLUSIONS: Foxp3 cells are increased in the duodenum of patients with untreated FA, but these cells are not able to suppress the harmful immune response, indicated by the low expression of Foxp3 transcripts. The increase of TLR4 cells and their correlation with TCRgammadelta intraepithelial lymphocytes suggest a role for the innate immunity and intestinal microbiota in FA.

Transcription factors GATA-4 and GATA-6 in normal and neoplastic human gastrointestinal mucosa.

BACKGROUND: Human gastrointestinal mucosa regenerates vigorously throughout life, but the factors controlling cell fate in mature mucosa are poorly understood. GATA transcription factors direct cell proliferation and differentiation in many organs, and are implicated in tumorigenesis. GATA-4 and GATA-6 are considered crucial for the formation of murine gastrointestinal mucosa, but their role in human gastrointestinal tract remains unexplored. We studied in detail the expression patterns of these two GATA factors and a GATA-6 down-stream target, Indian hedgehog (Ihh), in normal human gastrointestinal mucosa. Since these factors are considered important for proliferation and differentiation, we also explored the possible alterations in their expression in gastrointestinal neoplasias. The expression of the carcinogenesis-related protein Indian hedgehog was also investigated in comparison to GATA factors. METHODS: Samples of normal and neoplastic gastrointestinal tract from children and adults were subjected to RNA in situ hybridization with 33P labelled probes and immunohistochemistry, using an avidin-biotin immunoperoxidase system. The pathological tissues examined included samples of chronic and atrophic gastritis as well as adenomas and adenocarcinomas of the colon and rectum. RESULTS: GATA-4 was abundant in the differentiated epithelial cells of the proximal parts of the gastrointestinal tract but was absent from the distal parts. In contrast, GATA-6 was expressed throughout the gastrointestinal epithelium, and in the distal gut its expression was most intense at the bottom of the crypts, i.e. cells with proliferative capacity. Both factors were also present in Barrett's esophagus and metaplasia of the stomach. GATA-6 expression was reduced in colon carcinoma. Ihh expression overlapped with that of GATA-6 especially in benign gastrointestinal neoplasias. CONCLUSION: The results suggest differential but overlapping functions for GATA-4 and GATA-6 in the normal gastrointestinal mucosa. Furthermore, GATA-4, GATA-6 and Ihh expression is altered in premalignant dysplastic lesions and reduced in overt cancer.

Immunologic activity in the small intestinal mucosa of pediatric patients with type 1 diabetes.

Involvement of gut immune system has been implicated in the pathogenesis of type 1 diabetes. However, few studies have been performed on the gut mucosa from patients with type 1 diabetes. Thus, we characterized the stage of immune activation in jejunal biopsy samples from 31 children with type 1 diabetes by immunohistochemistry, in situ hybridization, and RT-PCR. We found enhanced expressions of HLA-DR, HLA-DP, and intercellular adhesion molecule-1 by immunohistochemistry even on structurally normal intestine of patients with type 1 diabetes and no signs of celiac disease. In addition, the densities of IL-1 alpha- and IL-4-positive cells detected by immunohistochemistry and IL-4 mRNA-expressing cells evaluated by in situ hybridization were increased in the lamina propria in patients with type 1 diabetes and normal mucosa. Instead, the densities of IL-2, gamma-interferon (IFN-gamma), and tumor necrosis factor alpha-positive cells, the density of IFN-gamma mRNA positive cells, and the amounts of IFN-gamma mRNA detected by RT-PCR correlated with the degree of celiac disease in patients with type 1 diabetes. Our study supports the hypothesis that a link exists between the gut immune system and type 1 diabetes.

Differential expression of GATA-4 and GATA-6 in fetal and adult mouse and human adrenal tissue.

Earlier work implicates transcription factors GATA-4 and GATA-6 in murine adrenal function. We have now studied their expression during mouse and human adrenal development in detail. GATA-4 and GATA-6 mRNAs and protein are readily detectable from embryonic d 14 and gestational wk 19 onwards in the mouse and human adrenal cortex, respectively. In the postnatal adrenal, GATA-4 expression is down-regulated, whereas GATA-6 mRNA and protein continue to be expressed. To clarify the significance of GATA-4 for early adrenocortical development, Gata4-/- ES cells were injected into eight-cell-stage embryos derived from ROSA26 mice, a transgenic line expressing beta-galactosidase in all cell types, including the adrenocortical cells. The resultant chimeric embryos were stained with X-gal to discriminate ES cell- and host-derived tissue. Gata4-/- cells contributed to adrenocortical cells in these chimeras, and these cells also expressed GATA-6. Taken together, our findings suggest that GATA-6 expression is needed throughout adrenal development from fetal to adult age. GATA-4, on the other hand, may serve a role in the fetal adrenal gene regulation, although it is not essential for early adrenocortical differentiation.

In Crohn's Disease, Anti-TNF-α Treatment Changes the Balance between Mucosal IL-17, FOXP3, and CD4 Cells.

Aim. In Crohn's disease (CD), anti-TNF-α treatment is a potent medication. We aimed to characterize the effect of anti-TNF-α treatment on T effector and regulatory cells. Material and Methods. We studied T-effector and regulatory cells on cellular and mRNA levels in intestinal biopsy samples from 13 Crohn's disease patient. Biopsies were obtained at baseline and 3 months after anti-TNF-α treatment, and from 14 inflammation-free control subjects. Results. Patients had higher numbers of ileal IL-17(+) and forkhead box P3 (FOXP3)(+) cells than did control subjects, both before ( P ≤ 0.001 and P ≤ 0.05, resp.) and after the anti-TNF-α treatment (P ≤ 0.01, P ≤ 0.01). Intestinal interferon-γ and IL-17 mRNA expression was higher in Crohn's disease and remained elevated after anti-TNF-α treatment. The ratio of IL-17(+) cells to CD4(+) cells decreased (P ≤ 0.05) and compared to baseline the ratio of IL-17(+) cells to FOXP3(+) was lower after treatment (P ≤ 0.05). Conclusions. TNF-α-blocking agents improved intestinal balance between IL-17(+) T-effector and regulatory T cells, although intestinal IL-17 upregulation remained elevated.

IL-23/IL-17 immunity as a hallmark of Crohn's disease.

BACKGROUND: We studied the balance between ileal T-effector cells versus T-regulatory cells in active and inactive Crohn's disease (CD). METHODS: We compared effector and regulatory T-cell-related markers such as interleukin (IL)-17, interferon (IFN)-gamma, IL-4, and Foxp3 transforming growth factor (TGF)-beta CTLA-4 and markers for innate immune activation such as IL-6, IL-10, IL-18, IL-23, tumor necrosis factor (TNF)-alpha, and IL-12p70, studied with immunohistochemistry and RT-PCR in ileal biopsies from patients with active or inactive CD and from control subjects. IL-17 in fecal samples was detected by ELISA. The effect of IL-17 on IL-8 and TNF-alpha mRNA expression in epithelial cell line Caco-2 was studied. RESULTS: The numbers of IL-4-, IL-17-, and IL-23(p19)-positive cells in the lamina propria were higher in patients with CD, both active and inactive, than in the controls. mRNA expression of IL-17A, IL-6, and Foxp3 was increased in the biopsies both from patients with active disease and those in remission, whereas mRNA expression of IL-23 was increased only in active disease. Fecal IL-17 concentration was increased in patients with active disease. IL-17 enhanced the IL-8 and TNF-alpha response of the epithelial cell line to lipopolysaccharide (LPS) in vitro. CONCLUSIONS: Our findings suggest that activation of the IL-23/IL-17 axis is fundamentally connected to the etiology of CD and may represent the basis for the relapsing nature of the disease by increasing the sensitivity of epithelium to microbial LPS.

Metalloelastase (MMP-12) is upregulated in the gut of pediatric patients with potential celiac disease and in type 1 diabetes.

OBJECTIVE: A slight to moderate increase in autoantibodies to transglutaminase 2 (TG2), but no morphological evidence of villous atrophy to confirm the diagnosis of celiac disease (CD) poses a challenge for clinicians. Our aim was to study the matrix metalloproteinase (MMP) profile, proliferative and apoptotic characteristics of jejunal biopsies obtained from such pediatric patients in order to find markers predictive of early changes in extracellular matrix degrading enzymes in the development of CD. MATERIAL AND METHODS: Twenty-eight children with positive screening tests (increase in transglutaminase and/or endomysium antibodies), but minor histological changes in the gut (Marsh grade 0-2), were studied and followed up for 2-3 years. In situ hybridizations for MMP-1, -3 and -12 were performed and sections were immunostained for MMP-19 and -26. Proliferating cells were identified by Ki-67 immunostaining and apoptotic cells using the TUNEL technique. RESULTS: MMP-12 was detected in macrophages in 16/28 samples and its expression was associated with increased autoantibodies for TG2 and densities of CD3 and gammadelta positive T-cells in the epithelium. The number of stromal MMP-26 positive cells was high in patients with high TG2 titers. Expression of MMP-12, MMP-1 and -3 clustered in children with type 1 diabetes (T1D) and the proportion of apoptotic mucosal cells was increased in patients with T1D compared to the others. When children with CD were compared to those who did not develop it, the numbers of IEL, cryptal Ki-67, CD-3, and MMP-12 positive cells were higher and showed the most significant differences. CONCLUSIONS: In pediatric patients, increased numbers of MMP-12 positive macrophages in lamina propria associate with high titers of antibodies to TG2 and proness to CD. A stage of mild inflammation may contribute to the upregulation of MMPs in the gut of patients with T1D.

Cytokines and adhesion molecules in duodenal mucosa of children with delayed-type food allergy.

OBJECTIVES: The aim was to investigate the expression of cytokines, adhesion molecules, and activation and proliferation markers in duodenal biopsies from children with delayed-type food allergy (FA). METHODS: Seven children with untreated FA (uFA), seven children with treated FA (tFA) to cow milk and/or cereals, and five normal controls furnished duodenal biopsy specimens. Additionally, five pediatric patients with celiac disease were included, serving exclusively as positive controls for in situ hybridization. Interferon-gamma (IFN-gamma), interleukin-4 (IL-4), adhesion molecules, and activation markers were detected by immunohistochemistry, and expression of IFN-gamma and IL-4 messenger RNA was revealed by in situ hybridization. RESULTS: uFA patients had a higher density of IFN-gamma positive cells in the lamina propria than did tFA patients and controls (P = 0.053 and P = 0.018). Moreover, the uFA patients exhibited a higher proportion of crypt cells in mitosis than did tFA patients (P = 0.026), and stronger staining of HLA-DR in the crypts and increased density of gammadelta-T cell receptor-positive intraepithelial lymphocytes than did controls (P = 0.048 and P = 0.010). The densities of alpha(4)beta(7) positive cells in the lamina propria tended to be higher in controls than in uFA or tFA patients (P = 0.106, P = 0.073). Expression of IL-4 mRNA was significantly higher in celiac patients than in the other study groups (uFA P = 0.006, tFA P = 0.010; controls P = 0.029), and celiac patients showed higher expression of IFN-gamma mRNA than did tFA patients or controls (P = 0.017 and P = 0.016). CONCLUSIONS: As expected, Th1 dominance was present in the lamina propria of children with delayed-type FA. It may cause activation of epithelial cells and increase their turnover.