RESUMEN
Alterations in the intestinal microbial flora have been linked with autoimmune diseases. Our objective was to analyse the composition of the faecal microbiome of children with new-onset juvenile idiopathic arthritis (JIA) compared to healthy controls, and to identify specific gut bacteria associated with JIA. Stool samples from patients were taken at the time of diagnosis of JIA. The microbiome profiles of samples of 30 children with JIA (mean age 6.2 years, 22 girls) were analysed with 16S region-based sequencing profiling and compared to the stool samples of healthy controls (n = 27, mean age 5.4 years, 18 girls). The proportion of bacteria belonging to the phylum Firmicutes was significantly lower in children with JIA [21 % (95 % confident interval [CI]: 17-25 %)] compared to controls [33 % (95 % CI: 26-41 %), p = 0.009]. Bacteria belonging to Bacteroidetes were significantly more abundant in JIA [78 % (95 % CI: 74-82 %)] than in control samples [65 % (95 % CI: 57-73 %), p = 0.008]. Shared operational taxonomic units (OTUs) between the groups revealed that genera Actinobacteria and Fusobacteria were present only in JIA patients and Lentisphaerae only in controls. In summary, faecal flora in JIA is characterised by a low level of Firmicutes and an abundance of Bacteroidetes, resembling the aberration reported in type 1 diabetes. We suggest that alterations in the intestinal microbial flora may challenge the mucosal immune system of genetically susceptible subjects predisposing to local proinflammatory cascades, thus contributing to the development of JIA.
Asunto(s)
Artritis Juvenil/etiología , Heces/microbiología , Microbiota , Antiinflamatorios no Esteroideos/uso terapéutico , Anticuerpos Antinucleares/inmunología , Artritis Juvenil/diagnóstico , Artritis Juvenil/tratamiento farmacológico , Estudios de Casos y Controles , Niño , Preescolar , Biología Computacional/métodos , Femenino , Microbioma Gastrointestinal , Genes Bacterianos , Genes de ARNr , Antígeno HLA-B27/inmunología , Humanos , Masculino , Metagenoma , MetagenómicaRESUMEN
The objective of this study was to assess the expression of protease inhibitor 9, a granzyme B inhibitor, in human small intestine, and to evaluate its cytoprotective role in the celiac disease of children. Twelve subjects with untreated celiac disease and thirteen healthy controls were examined by endoscopy. The expression of protease inhibitor 9 was analyzed immunohistochemically from duodenal biopsies and compared to granzyme B expression, apoptosis rate, number of intraepithelial lymphocytes and villus and crypt height data from the biopsies. We discovered that protease inhibitor 9 is expressed in the cytoplasm of the duodenal epithelial cells in the majority of cases. The enterocyte expression of protease inhibitor 9 was lower in celiac disease patients than in controls. Protease inhibitor 9 expression also showed a negative correlation with the number of apoptotic cells, overall density of granzyme B expressing intraepithelial lymphocytes, the height of the crypts and the severity of villous atrophy in duodenum. Therefore, we conclude that the protease inhibitor 9 is constantly expressed in the enterocytes of normal duodenum and the expression is decreased in celiac disease. These findings suggest that protease inhibitor 9 has a role in duodenal homeostasis and in the protection of enterocytes from misdirected granzyme B. Indeed, observed associations of lowered protease inhibitor 9 expression together with increased granzyme B expression, apoptosis rate and severity of villous atrophy suggest that impaired balance between granzyme B mediated cytotoxicity and its inhibition by protease inhibitor 9 forms an important factor in the pathogenesis of villous atrophy in celiac disease.
Asunto(s)
Enfermedad Celíaca/patología , Enterocitos/patología , Granzimas/fisiología , Mucosa Intestinal/patología , Serpinas/análisis , Adolescente , Apoptosis , Atrofia , Enfermedad Celíaca/metabolismo , Niño , Preescolar , Femenino , Granzimas/antagonistas & inhibidores , Humanos , MasculinoRESUMEN
We aimed to study intestinal immune activation status in juvenile idiopathic arthritis (JIA) by assessing intestinal human leucocyte antigen (HLA) class II expression and the mRNA expression levels of the pro- and anti-inflammatory mediators and pattern recognition receptors. HLA-D-related (HLA-DR) expression was assessed using immunohistochemical staining of frozen sections in 11 children with JIA and 17 controls. The gene expression levels of the anti- and proinflammatory cytokines, lymphocyte recognition receptors and pattern recognition receptors were studied with reverse transcription-polymerase chain reaction (RT-PCR) in 14 children with JIA and 12 controls. All subjects had various gastrointestinal (GI) symptoms indicating endoscopic examinations, but eventually were not diagnosed with GI disease. In JIA patients, the expression of HLA-DR was increased in the crypt epithelial cells and in the epithelial basement membrane of the ileum when compared with the controls. Positive HLA-DR staining in the ileal mucosa was associated with the presence of high clinical disease activity of JIA and low mRNA expression of anti-inflammatory mediators, such as forkhead box protein P3 (FoxP3), glucocorticoid-induced tumour necrosis factor receptor-related protein (GITR) and transforming growth factor (TGF)-beta. Low ileal expression of interleukin (IL)-10, TGF-ß, FoxP3, Toll-like receptor 2 (TLR-2) and TLR-4 transcripts correlated significantly with a high clinical disease activity in the JIA patients. The increased HLA-DR expression suggests enhanced intestinal antigen presentation in JIA. A correlation between clinical disease activity and low gene expression of tolerogenic mediators in the ileum supports the hypothesis that a link exists between the gut immune system and JIA.
Asunto(s)
Artritis Juvenil/genética , Artritis Juvenil/inmunología , Regulación de la Expresión Génica , Antígenos HLA-DR/genética , Mucosa Intestinal/inmunología , Mucosa Intestinal/metabolismo , Transducción de Señal , Adolescente , Artritis Juvenil/patología , Estudios de Casos y Controles , Niño , Preescolar , Citocinas/genética , Citocinas/inmunología , Femenino , Humanos , Íleon/inmunología , Íleon/metabolismo , Íleon/patología , Mediadores de Inflamación/inmunología , Mediadores de Inflamación/metabolismo , Mucosa Intestinal/patología , MasculinoRESUMEN
OBJECTIVE: Intestinal gamma/delta- intraepithelial lymphocytes (IEL) have increased in children with juvenile idiopathic arthritis (JIA). To further characterise intestinal immune activation in these children, we have quantitated cytotoxic lymphocytes in intestinal mucosa. METHODS: We studied 23 children with JIA suffering from gastrointestinal symptoms with gastroduodenoscopy and colonoscopy. The control children (n=20) had GI-symptoms but eventually shown not to have any significant gastrointestinal disease. Granzyme A (GrA) and Granzyme B (GrB) expressing lymphocytes in the epithelium and lamina propria were counted in immunostained sections of ileal and duodenal biopsies. RESULTS: The number of GrB expressing IELs was increased in duodenal mucosa in patients with JIA. In the ileum the number of both GrB and GrA positive IELs was similarly increased. No significant differences in the counts of the lamina propria GrA or GrB expressing cells were observed. Granzyme expression was not associated with the duration or with the severity of the disease, or with medication. CONCLUSIONS: These observations suggest that lymphocyte cytotoxicity is abnormally increased in the intestinal mucosa in JIA. Since a similar pattern of activation has been seen in food allergy and celiac disease, we speculate that some luminal, possibly a nutritional factor may be involved in JIA as well. Further studies are needed to see whether cytotoxic activation plays any role in the pathogenesis of JIA.
Asunto(s)
Artritis Juvenil/inmunología , Duodeno/inmunología , Íleon/inmunología , Mucosa Intestinal/inmunología , Linfocitos T Citotóxicos/inmunología , Adolescente , Artritis Juvenil/patología , Biopsia , Niño , Preescolar , Duodeno/patología , Endoscopía Gastrointestinal , Femenino , Granzimas/metabolismo , Humanos , Íleon/patología , Lactante , Mucosa Intestinal/patología , Masculino , Membrana Mucosa/inmunología , Membrana Mucosa/patología , Linfocitos T Citotóxicos/metabolismo , Linfocitos T Citotóxicos/patologíaRESUMEN
OBJECTIVES: Heat shock proteins (HSPs) are involved in the regulation of inflammation and in the maintenance of mucosal integrity. Their altered expression may be a marker of mucosal inflammation and also contribute to tissue injury. The small intestinal mucosa in children with juvenile idiopathic arthritis (JIA) shows signs of intestinal immune activation, such as increased intraepithelial cytotoxic lymphocyte counts. To further evaluate the characteristics of this immune activation in JIA, we have studied the expression of several HSPs, major histocompatibility complex (MHC) class I-related chain A (MICA), and the heat shock transcription factor 1 (HSF1) in intestinal biopsies from children with JIA. METHODS: We studied 15 patients with JIA. Controls included 13 children without JIA, studied for various gastrointestinal (GI) symptoms, but eventually shown not to have any GI disease. The subjects were examined by endoscopy. The expression of HSP60, HSP70, MICA, and HSF1 was analysed in ileal and duodenal biopsies by using immunohistochemistry. RESULTS: The expression levels of HSP60, MICA, and HSF1 were significantly lower in the duodenal epithelium in the JIA patients compared to the controls. MICA and HSF1 also showed lower expression in the ileal epithelium. The expression of HSP70 did not differ between the groups. CONCLUSIONS: The downregulation of HSP60, MICA, and HSF1 in small intestinal mucosa may indicate that intestinal epithelial cells show immune aberration in JIA. We speculate that the low heat shock response may play a role in the pathogenesis of JIA, interfering with mucosal integrity and local intestinal immunoregulation.
Asunto(s)
Artritis Juvenil/metabolismo , Chaperonina 60/metabolismo , Proteínas de Unión al ADN/metabolismo , Proteínas HSP70 de Choque Térmico/metabolismo , Antígenos de Histocompatibilidad Clase I/metabolismo , Mucosa Intestinal/metabolismo , Factores de Transcripción/metabolismo , Adolescente , Artritis Juvenil/inmunología , Chaperonina 60/inmunología , Niño , Preescolar , Proteínas de Unión al ADN/inmunología , Duodeno/inmunología , Duodeno/metabolismo , Femenino , Proteínas HSP70 de Choque Térmico/inmunología , Factores de Transcripción del Choque Térmico , Antígenos de Histocompatibilidad Clase I/inmunología , Humanos , Íleon/inmunología , Íleon/metabolismo , Inmunohistoquímica , Inflamación/inmunología , Inflamación/metabolismo , Mucosa Intestinal/inmunología , Masculino , Estadísticas no Paramétricas , Linfocitos T/inmunología , Linfocitos T/metabolismo , Factores de Transcripción/inmunologíaRESUMEN
OBJECTIVES: To examine the prevalence of immune activation in gastrointestinal (GI) mucosa in children with juvenile idiopathic arthritis (JIA) or connective tissue disease (CTD). STUDY DESIGN: We studied 27 children (15 girls, mean age 9.8+/-4.8 years) with JIA/CTD and GI symptoms, including nine with oligoarthritis, nine with polyarthritis, two with systemic arthritis, three with enthesitis-related arthritis, and four with various CTDs. The control group consists of 54 children (31 girls, mean age 11.3+/-6.3 years) with GI symptoms but shown to have no significant GI or rheumatoid disorder. The subjects were examined by gastroduodenoscopy (22 patients, 50 controls) and colonoscopy (23 patients, 16 controls). Intraepithelial CD3+, alpha/beta+, and gamma/delta+ lymphocytes were counted from duodenal and ileal biopsies. RESULTS: Five patients with JIA/CTD (19%) had ulcerative colitis. Lymphoid nodular hyperplasia (LNH) was more common in the patients [74% (20/27)] than in the controls [16% (8/50), p = 0.001], as well in the duodenal bulb [29% (7/24) vs. 10% (5/50)], terminal ileum [74% (14/19) vs. 38% (5/13)], and the colon [50% (11/22) vs. 14% (2/14)]. In the duodenum, CD3, alpha/beta+, and gamma/delta+ lymphocytes counts were higher in JIA/CTD (p<0.05). In the ileum, gamma/delta+ cell numbers had increased in JIA/CTD (p<0.05). Either LNH, increased gamma/delta+ count, or both were more common in JIA/CTD [89% (24/27)] than in the controls [13% (7/54), p<0.0001]. CONCLUSIONS: The majority of children suffering from JIA or CTD with GI symptoms show abnormalities consistent with activation of the intestinal immune system. The aetiology of this reaction remains unknown, but similar features are seen in delayed-type food allergy.