Surface layer proteins from Clostridium difficile induce inflammatory and regulatory cytokines in human monocytes and dendritic cells.

Clostridium difficile, an etiological agent of most cases of antibiotic-associated diarrhea, exerts its pathological action mainly by the activity of toxin A and toxin B. Less known is the role that S-layer proteins (SLPs), predominant surface components of the bacterium, may play in pathogenesis. Here, we evaluate the ability of SLPs to modulate the function of human monocytes and dendritic cells (DC) and to induce inflammatory and regulatory cytokines, influencing the natural and adaptive immune response. To this aim, SLPs were extracted from the clinical isolate C253 and characterized for their effects on immune cells. SLPs induced the release of elevated amounts of interleukin (IL)-1beta and IL-6 pro-inflammatory cytokines by resting monocytes, induced maturation of human monocyte-derived DC (MDDC), and enhanced proliferation of allogeneic T cells. C253-SLP-treated MDDC also secreted large amounts of IL-10 and IL-12p70 and induced a mixed Th1/Th2 orientation of immune response in naïve CD4 T cells. In conclusion, C. difficile SLPs may contribute to the pathogenicity of the bacterium by perturbing the fine balance of inflammatory and regulatory cytokines. These data are of interest also in the light of the possible use of SLPs in a multicomponent vaccine against C. difficile infections for high-risk patients.

Serum levels of seven cytokines in premature ventilated newborns: correlations with old and new forms of bronchopulmonary dysplasia.

OBJECTIVE: In addition to the previous classification of chronic lung disease (CLD) O2 dependency at 36 weeks of postmenstrual age, a new definition of CLD has recently been proposed: new bronchopulmonary-dysplasia (BPD). This uses total duration of O2 supplementation and positive pressure requirements to delineate three degrees of severity (mild, moderate, and severe) according to the respiratory status at 36 weeks postmenstrual age. We analyzed the balance of serum proinflammatory and profibrotic/angiogenic cytokine concentrations in relation to CLD and the new BPD definition. DESIGN AND SETTING: Descriptive study in a third-level neonatal ICU. PATIENTS: Thirty-one preterm neonates with a gestational age of 24-29 weeks were studied to evaluate their serum cytokine concentration; they were previously enrolled in a randomized clinical trial to compare the effects of high-frequency oscillatory ventilation vs. intermittent mandatory ventilation in terms of pulmonary mechanics and lung cytokines. Serum samples were collected on days 1, 3, and 5 after birth until extubation to detect the levels of three proinflammatory cytokines plus four profibrotic/angiogenic cytokines, and correlations were examined to old CLD and new BPD. Ventilation treatments were distributed homogeneously between the groups and did not interfere with the results presented here. RESULTS AND CONCLUSIONS: Old CLD development, mainly corresponding to the moderate/severe forms of new BPD, was associated with increased proinflammatory and profibrotic/angiogenic cytokines, while mild forms of new BPD were characterized only by increases in profibrotic/angiogenic cytokines, suggesting a different balance of two pathogenic mechanisms in different phases of the disease.

Perceptual-motor abilities in pre-school preterm children.

BACKGROUND: Several studies report a high percentage of premature infants presenting perceptual motor difficulties at school age. The new version of the Movement Assessment Battery for Children allows the assessment of perceptual-motor abilities in children from the age of 3years. AIMS: To evaluate early perceptual-motor abilities in prematurely born children below the age of 4years. STUDY DESIGN: The Movement Assessment Battery for Children 2nd edition was administered to 105 low-risk prematurely born children (<32weeks gestation) and in a control group of 105 term-born children matched for age and sex. All children were assessed between the age of 3years and 3years-11months. RESULTS: 63 children (60%) had total scores above the 15th percentile, 15 (14.3%) had scores between the 5th and the 15th percentile, and 13 (12.4%) below the 5th percentile. The remaining 14 children (13.3%) refused to perform or to complete the test. The difference between preterm and control group was significant for total scores, Manual Dexterity and Aiming and Catching scores. In the preterm group there was a correlation between age at testing, total scores and Aiming and Catching subscores. The Movement ABC-2 subscores were significantly lower in children born below 29weeks. CONCLUSION: Perceptual-motor difficulties can already be detected on the assessment performed before the age of 4years. Prematurely born children assessed between 3years and 3years-3months appeared to have more difficulties in performing the test than the older ones or their age matched term-born peers. These findings support the possibility of a delayed maturation in the younger age group.