Gut-associated bacterial microbiota in paediatric patients with inflammatory bowel disease.

BACKGROUND: Clinical and experimental observations in animal models indicate that intestinal commensal bacteria are involved in the initiation and amplification of inflammatory bowel disease (IBD). No paediatric reports are available on intestinal endogenous microflora in IBD. AIMS: To investigate and characterise the predominant composition of the mucosa-associated intestinal microflora in colonoscopic biopsy specimens of paediatric patients with newly diagnosed IBD. METHODS: Mucosa-associated bacteria were quantified and isolated from biopsy specimens of the ileum, caecum and rectum obtained at colonoscopy in 12 patients with Crohn's disease, 7 with ulcerative colitis, 6 with indeterminate colitis, 10 with lymphonodular hyperplasia of the distal ileum and in 7 controls. Isolation and characterisation were carried out by conventional culture techniques for aerobic and facultative-anaerobic microorganisms, and molecular analysis (16S rRNA-based amplification and real-time polymerase chain reaction assays) for the detection of anaerobic bacterial groups or species. RESULTS: A higher number of mucosa-associated aerobic and facultative-anaerobic bacteria were found in biopsy specimens of children with IBD than in controls. An overall decrease in some bacterial species or groups belonging to the normal anaerobic intestinal flora was suggested by molecular approaches; in particular, occurrence of Bacteroides vulgatus was low in Crohn's disease, ulcerative colitis and indeterminate colitis specimens. CONCLUSION: This is the first paediatric report investigating the intestinal mucosa-associated microflora in patients of the IBD spectrum. These results, although limited by the sample size, allow a better understanding of changes in mucosa-associated bacterial flora in these patients, showing either a predominance of some potentially harmful bacterial groups or a decrease in beneficial bacterial species. These data underline the central role of mucosa-adherent bacteria in IBD.

Contrast enhanced magnetic resonance imaging of the terminal ileum in children with Crohn's disease.

BACKGROUND AND AIMS: Recently, magnetic resonance imaging (MRI) has been introduced in the diagnosis of patients with inflammatory bowel disease (IBD). However, it is still rarely reported in paediatric IBD. We studied the diagnostic value of gadolinium enhanced MRI in revealing inflammation of the distal ileum in children with Crohn's disease (CD) and in differentiating them from patients with other inflammatory diseases of the gut. MRI was performed using a polyethylene glycol (PEG) solution as oral contrast agent to distend the small bowel (CE-PEG-MRI). SUBJECTS AND METHODS: Seventy five consecutive patients (median age 13.6 years, range 8-17) with suspected CD underwent ileocolonoscopy with biopsy and CE-PEG-MRI. CD activity was measured by the paediatric Crohn's disease activity index (PCDAI). CE-PEG-MRI was evaluated with an overall score calculated, taking into account both wall thickness and contrast enhancement. RESULTS: Active CD with distal ileitis was diagnosed in 26 cases, active ulcerative colitis (UC) in 18, and spondyloarthropathy and indeterminate ileocolitis in 11; 20 children served as controls. In all CD patients, CE-PEG-MRI revealed a marked ileal involvement with increased wall thickness and parietal contrast enhancement and showed a high concordance with endoscopy and histology, whereas the test was negative in all controls. Of the 18 UC patients, CE-PEG-MRI was negative in 15 and showed a mild parietal contrast enhancement of the terminal ileum in only three of seven patients with backwash ileitis. Among the group of spondyloarthropathy patients, six had mucosal erosions and five mild superficial ileitis: CE-PEG-MRI was negative in four and revealed only mild parietal contrast enhancement of the ileal wall in seven. CE-PEG-MRI did not show an increase in wall thickness of the distal ileum in any of the UC or spondyloarthropathy patients. The sensitivity and specificity of CE-PEG-MRI related to the presence of erosive ileitis, as documented by endoscopy, were 84% and 100%, respectively. In addition, the test correlated markedly with endoscopy and histology in the entire population (r=0.94; r=0.95, respectively) as well as with the PCDAI in CD patients (r=0.91). CONCLUSIONS: In children with active CD, CE-PEG-MRI is a very sensitive and specific test for the detection of distal ileitis and for differentiation from other inflammatory diseases of the gut. The test could also be useful for the firstline diagnostic approach in children with suspected CD. The high correlation of CE-PEG-MRI with ileal endoscopy and histology as well as with PCDAI makes this test of great interest for future studies as a tool for monitoring the clinical course and the effect of therapy in CD patients.

New therapeutic approach in the management of intestinal disease: probiotics in intestinal disease in paediatric age.

Current evidence supports the view that oral administration of probiotics may be of therapeutic usefulness in several clinical disorders by reestablishing normal flora in the gastrointestinal tract. These entities include inflammatory and infectious diseases of the gut as well as extraintestinal disorders (such as atopic eczema) in which a defective intestinal permeability plays a role. The probiotic effects are attributed to restoration to normal of increased intestinal permeability, unbalanced gut microecology, improved immunological gut barrier function, downregulation of the intestinal inflammatory responses with reduced generation of proinflammatory cytokines. Entities for which the impact of probiotic administration can be considered as proven are Rotavirus diarrhoea, Clostridium difficile diarrhoea, post-antibiotic diarrhoea, allergic diseases. On the other hand, entities for which administration of probiotics is considered under investigation are inflammatory bowel disease, necrotizing enterocolitis, cystic fibrosis, small bowel bacterial contamination, functional gastrointestinal disorders. The value of probiotics as therapy for a variety of gastrointestinal disorders in childhood still needs to be investigated in detail, through well controlled and rigorous studies, including a placebo group and strict criteria of randomisation. Much work needs to be done in this area by clearly defining indications, delivery system, costs, safety long-term effects.

Food allergy and asthma.

Food allergy (FA) is one of the causes of atopic dermatitis (AD), of acute urticaria, of reactions of the gastrointestinal tract, and of acute systemic anaphylaxis, but its role in asthma appears to be less clear. The prevalence and incidence of subjects with food-induced wheezing have not been well studied. In addition, the number of subjects with proven food-induced wheezing by double-blind, placebo-controlled oral food challenge (DBPCOFC) has been small. At the moment wheezing is considered unusual in food-hypersensitive subjects, and wheezing as the unique symptom of FA is rare. Furthermore, most cases of food-induced asthma have been observed in children. Food allergy may trigger allergic respiratory symptoms through two main routes: ingestion or inhalation. Children with asthma, who are allergic to foods, present some particular features such as AD and a related significantly elevated total serum IgE level. Alternatively, FA may occur in patients who are "high IgE responder" and more prone to become sensitive to many allergens, including foods. Therefore, children with asthma and a history of AD and/or elevated total serum IgE level should be carefully assessed for FA. We have shown that a significant proportion of children with IgE-mediated cow's milk allergy experienced asthma following DBPCOFC with cow's milk.

Nutritional epidemiology during school age.

Nutritional research covers different fields, two of which are of particular interest: evaluation of the nutritional status, and epidemiology of food consumption. For many years, studies in these fields have been promoted by our research group, which bases its methodology on anthropometric measurements, bioelectrical impedance measurements, and check of nutritional habits. Our studies involve more than 2500 subjects from pre-school age to adolescence. This work represents the basis for an educational approach with the ultimate aim of improving life styles. One of our first studies on school meals during nursery period and composition and application of "dietary tables" showed inadequacies of energy intakes and macronutrients distribution. In another study, aimed to evaluate the intake of soluble sugars, more than 2/3 of participating school children were found to consume more than 70 g of soluble sugars per day, while 10% of them exceeded 150 g/day. Results of the following study, in which special attention was given to salted and sweet snacks, showed that snacks can account for 34% of the total daily energy intake; although its adequacy, the energy distribution per macronutrients showed a clear imbalance. As for adolescence, a very critical age, the evaluation of weight self-perception revealed that only 62% of them had a correct perception of their weight. This research also devoted special attention to home prepared breakfast, which is consumed by the vast majority of enrolled subjects, although only rarely it is nutritionally adequate. A double age-related trend could thus be drawn: on one side, there is the tendency of the "overweight status" to decrease (from a starting-point of about 20%); on the other side, this tendency is unfortunately compensated by the increasing trend of "obesity" (which almost reaches 30%).

Multiple viral infections in HIV-infected children with chronically-evolving hepatitis.

Hepatic involvement was investigated in 31 children with perinatal HIV-1 infection, who were followed for 2-82 months (mean 30.5). Liver disease, as revealed by increased aminotransferase levels, liver biopsy or necroscopy, was diagnosed in 18 children (58%), of which 7 (22.5%) had acute hepatitis and 11 (35.5%) showed chronic liver disease. Overall, 40 persistently active or recurrent viral infections, as demonstrated by positive culture and/or detection of serum DNA, specific IgM, IgA and high levels of IgG, were revealed in the children with liver disease, while 12 similar infections were detected in 13 children without liver disease (p < 0.001). In particular, the children with liver disease showed a significantly (p < 0.002) higher incidence of cytomegalovirus (CMV) infections than children without liver disease (13 versus 3). Moreover, hepatitis C and B virus infections were revealed only in children with liver disease (5 and 1 patients, respectively). Clinical outcome showed a significantly (p < 0.001) higher mean survival in the children without liver disease than those with liver disease (47.5 versus 18.2 months). In fact, nine of the children with liver disease (50%) died, as opposed to only one of the children without liver disease (7.7%; p = 0.01). Based on these findings, liver disease is indicative of a poor prognosis in children with HIV infection, being related to the presence of multiple active viral infections.

Post-transfusional human retrovirus infection in 41 Italian beta-thalassemic patients.

BACKGROUND: Previous studies have demonstrated that HTLV-I is present in Italy both in endemic form in Southern Apulia and in epidemic form among the population of intravenous drug addicts. In the present paper we intend to evaluate the risk for transfusional HTLV-I transmission in our country, as well as the already known risk for HIV1. METHODS: A population of 41 polytransfused Italian beta-thalassemic patients was examined by serological methods and PCR (polymerase chain reaction) for human retrovirus infection. Genomic DNA from PBMCs was analyzed by PCR with primer pairs specific for the HTLV-I gag, pol and env regions, and the HTLV-II env region. RESULTS: Two patients were found to be weakly seroreactive to p19 and p24 HTLV-I/HTLV-II proteins by Western blot. The analysis of genomic DNA from PBMCs by PCR revealed sequence homology to HTLV-I only in these two patients. On the contrary, PCR with primer pairs specific for HTLV-II showed no beta-thalassemic patient was infected by this retrovirus. Surprisingly, Western blot analysis for detecting anti-HIV1 antibodies in these polytransfused subjects showed a seropositivity in two patients (not the same found to be infected with HTLV-I) in spite of a screening for HIV1 antibodies in the blood bank. CONCLUSIONS: These findings suggest that in Italy polytransfused people should still be considered at risk for HIV1 as well as HTLV-I infection, even if the incidence cannot be evaluated from such a small sample. The authors stress the importance of a through medical history of potential blood donors to eliminate possibly infected subjects.

Radiological changes of the ileum in children with coeliac disease: is "intestinal adaptation" a specific radiographic sign?

We retrospectively reviewed the radiographic findings of 86 children with chronic diarrhoea and/or short stature. Radiographic small intestine examination showed morphologic changes characteristic for the malabsorption syndrome in 58 children with coeliac disease on a gluten-containing diet. In addition, 32 (55%) of these children showed "intestinal adaptation" or "jejunalization" (increase in the number and thickness of the folds). In the control group (28 children, cross-matched) 11 (39%) presented non specific radiological changes while the others presented a normal mucosal pattern. No features of "intestinal adaptation" were noted. No significant differences between CD patients with and without "intestinal adaptation" were found in the evaluation of the nutritional status, including serum levels of albumin, iron, transferrin, ferritin and zinc, and in the results of the one-hr xylose test and 72-hr faecal fat absorption test, and anti-gliadin antibody levels (IgA and IgG). No significant correlation was noted between the duration of gluten-containing diet and the presence of "intestinal adaptation". It appears that "intestinal adaptation" lends specificity to the radiographic small intestine examination, also in paediatric practice.

Reference values for essential and toxic elements in human milk.

Dependable reference values (RVs) for the concentration ranges of health-related elements in human biological fluids and organs are to date of acknowledged importance for an early recognition of pathological states. On the other hand, the present lack of reliable data on levels to be considered as baseline values for elements of major concern from a toxicological, environmental and nutritional point of view demands the development of experimental procedures capable of satisfying the requirements of detection power, specificity and applicability on a large scale necessary to generate vast amounts of reliable measurements. As part of an overall monitoring program, an investigation was undertaken with the following two aims: a) the present suitability of inductively-coupled plasma atomic emission spectrometry (ICP-AES) to identify and quantitate minor and trace elements in human milk with the necessary accuracy and precision; b) assessment of RV concentrations for Al, Ba, Cd, Cr, Cu, Fe, Li, Mg, Mn, Ni, Pb and Zn. Four population groups were selected (each with 9 subjects) resulting from the various combinations of smokers and non-smokers from an urban or a rural environment. Strict eligibility criteria were adopted in order to select only women in good health, no known occupational exposure and whose nutritional habits could be described in detail. A scrupolous and systematic approach was adopted to minimize every possible source of elemental contamination from the sampling step onwards. Digestion of samples was attempted both with mixtures of strong acids and by resorting to acid-assisted mineralization in a microwave oven. Both methods were satisfactory for subsequent introduction into the torch of the ICP-AES system. The outcome of this pilot study gave the following median RVs for concentration (in mg/kg): Al, 0.14; Ba, 0.013; Cd, 0.002; Cr, 0.016; Cu, 0.40; Fe, 0.72; Li, 0.004; Mg, 29.4; Mn, 0.006; Ni, 0.05; Pb, 0.016; and Zn, 3.08.

Acquired immune deficiency syndrome in childhood. Neurological aspects.

Central nervous system (CNS) involvement is very frequently observed in pediatric AIDS. Clinical manifestations include encephalopathy, cognitive deficits, acquired microcephaly, neurological signs, myelopathy, and peripheral neuropathy. Neurological complications can be related to opportunistic viral infections such as encephalitis, atypical aseptic meningitis, progressive multifocal leukoencephalopathy, and myelitis. Nonviral syndromes include: toxoplasmosis, cryptococcal meningitis, candidiasis, Mycobacterium tuberculosis meningitis, and Mycobacterium avium subacute encephalitis. Bacterial infections, tumors, cerebrovascular complications, and peripheral neuropathies are not frequently observed in pediatric AIDS. The most severe complications of HIV infection is encephalopathy resulting from HIV infection of brain tissue. Direct HIV invasion of the CNS has been demonstrated. Clinical features of HIV encephalopathy are classified into three categories: (1) normal neurological findings; (2) static encephalopathy; and (3) progressive encephalopathy. AIDS dementia complex can be differentiated from the predominance of behavioral and cognitive disabilities.

Iron deficiency in children with celiac disease.

To evaluate the incidence of either evident anemia or a subclinical status of iron deficiency in celiac disease (CD), we studied 80 celiac children aged 6 months to 18 years. They were subdivided into various groups according to morphology of gut mucosa and diet. Only eight of 47 celiac children had an evident anemia at the time of the first peroral bowel biopsy. In addition, 51% of the patients with atrophic mucosa and 56% of the children on a gluten-containing diet had serum iron levels less than 50 micrograms/dl; 35% of patients of both groups had serum ferritin levels less than 12 micrograms/L. On the contrary, only a small number of children with normal mucosa on a gluten-free diet showed a laboratory, subclinical picture of iron deficiency. The results of our study can therefore be summarized in three major items: (a) Low levels of both serum iron and ferritin can frequently be found during active CD. (b) Regular determination of serum iron levels appears to be useful in controlling the state of iron stores in such patients, as well as in deciding whether and when to recommend temporary iron supplementation. (c) Serum ferritin tests did not offer more information than the easier and cheaper serum iron determinations.