Antibiotic prophylaxis in neutropenic children with acute leukemia: Do the presently available data really support this practice?

Antibiotics are frequently administered for prophylaxis of fever in neutropenic children with cancer. This strategy is mainly derived from adults' data, and various pediatric studies evidenced the effectiveness of antibiotics (eg, fluoroquinolones) in the prevention of febrile neutropenia. However, only two pediatric randomized, double-blind, placebo-controlled trials have been performed, with a total of 262 leukemic children enrolled, and no other one was ever powered for analyzing effectiveness over other infectious complications. In an era of increasing antibiotic resistance, the widespread use of antibiotic prophylaxis in neutropenic leukemic children needs to be strongly supported.

Polar Effects on Ion Transport and Cell Proliferation Induced by GC-C Ligands in Intestinal Epithelial Cells.

Guanylin receptor guanylate cyclase (GC-C) peaks in neonatal intestine and is involved in either enterocyte proliferation or chloride secretion. The latter is more potent when GC-C activator guanylin, or its analog Escherichia coli heat-stable enterotoxin (ST), is added to the mucosal rather than serosal side of intestinal monolayers. By using Ussing chambers, we investigated transepithelial ion transport and enterocyte proliferation and their mechanisms in response to the addition of guanylin or ST to the mucosal or serosal side of Caco-2 monolayers and in ileal specimens from neonates. GC-C activation showed a polar pattern of the effects. GC-C mucosal activation resulted in a potent cGMP-chloride secretion activation and in a marginal enterocyte proliferation. Conversely, serosal GC-C activation induced a potent enterocyte proliferation, through MAP kinase ERK 1/2. Finally, the inhibition of ERK1/2 enhanced the Isc increase in response to serosal but not to mucosal ST stimulation, indicating that ERK1/2 also acts as a brake of chloride secretion. These data suggest that the guanylin/GC-C system plays a key role in early postnatal intestinal adaptation exploiting the polar structure of enterocyte.

Lack of efficacy of Lactobacillus GG in reducing pulmonary exacerbations and hospital admissions in children with cystic fibrosis: A randomised placebo controlled trial.

BACKGROUND: Intestinal dysbiosis has been described in Cystic Fibrosis (CF) and probiotics have been proposed to restore microbial composition. Aim of the study was to investigate the effects of Lactobacillus rhamnosus GG (LGG) on clinical outcomes in children with cystic fibrosis (CF). METHODS: A multicentre, randomised double-blind, clinical trial was conducted in children with CF. After 6months of baseline assessment, enrolled children (2 to 16years of age) received Lactobacillus GG (6×109CFU/day) or placebo for 12months. Primary outcomes were proportion of subjects with at least one pulmonary exacerbation and hospitalisation over 12months. Secondary endpoints were total number of exacerbations and hospitalisations, pulmonary function, and nutritional status. RESULTS: Ninety-five patients were enrolled (51/95 female; median age of 103±50months). In a multivariate GEE logistic analysis, the odds of experiencing at least one exacerbation was not significantly different between the two groups, also after adjusting for the presence of different microbial organisms and for the number of pulmonary exacerbations within 6months before randomisation (OR 0.83; 95% CI 0.38 to 1.82, p=0.643). Similarly, LGG supplementation did not significantly affect the odds of hospitalisations (OR 1.67; 95% CI 0.75 to 3.72, p=0.211). No significant difference was found for body mass index and FEV1. CONCLUSIONS: LGG supplementation had no effect on respiratory and nutritional outcomes in this large study population of children with CF under stringent randomised clinical trial conditions. Whether earlier interventions, larger doses, or different strains of probiotics may be effective is unknown.

Gastrointestinal and liver infections in children undergoing antineoplastic chemotherapy in the years 2000.

AIM: To review gastrointestinal and liver infections in children undergoing antineoplastic chemotherapy. To look at gut microflora features in oncology children. METHODS: We selected studies published after year 2000, excluding trials on transplanted pediatric patients. We searched English language publications in MEDLINE using the keywords: "gastrointestinal infection AND antineoplastic chemotherapy AND children", "gastrointestinal infection AND oncology AND children", "liver infection AND antineoplastic chemotherapy AND children", "liver abscess AND chemotherapy AND child", "neutropenic enterocolitis AND chemotherapy AND children", "thyphlitis AND chemotherapy AND children", "infectious diarrhea AND children AND oncology", "abdominal pain AND infection AND children AND oncology", "perianal sepsis AND children AND oncology", "colonic pseudo-obstruction AND oncology AND child AND chemotherapy", "microflora AND children AND malignancy", "microbiota AND children AND malignancy", "fungal flora AND children AND malignancy". We also analysed evidence from several articles and book references. RESULTS: Gastrointestinal and liver infections represent a major cause of morbidity and mortality in children undergoing antineoplastic chemotherapy. Antineoplastic drugs cause immunosuppression in addition to direct toxicity, predisposing to infections, although the specific risk is variable according to disease and host features. Common pathogens potentially induce severe diseases whereas opportunistic microorganisms may attack vulnerable hosts. Clinical manifestations can be subtle and not specific. In addition, several conditions are rare and diagnostic process and treatments are not standardized. Diagnosis may be challenging, however early diagnosis is needed for quick and appropriate interventions. Interestingly, the source of infection in those children can be exogenous or endogenous. Indeed, mucosal damage may allow the penetrance of endogenous microbes towards the bowel wall and their translocation into the bloodstream. However, only limited knowledge of intestinal dysbiosis in oncology children is available. CONCLUSION: The diagnostic work-up requires a multimodal approach and should be implemented (also by further studies on new biomarkers) for a prompt and individualized therapy.

Reduced central line infection rates in children with leukemia following caregiver training: A quality improvement study.

Infections are a leading cause of morbidity and mortality in children with acute leukemia. Central-line (CL) devices increase this population's risk of serious infections.Within the context of a quality improvement (QI) project, we tested the effect of caregiver education on CL management on the CL-associated bloodstream infection (CLABSI) rate among children with acute leukemia seen at a large referral center in Italy. The intervention consisted of 9 in-person sessions for education and practice using mannequins and children.One hundred and twenty caregivers agreed to participate in the initiative. One hundred and five (87.5%) completed the training, 5 (4.1%) withdrew after the first session, and 10 (8.3%) withdrew during practical sessions. After educational intervention, the overall CLABSI rate was reduced by 46% (from 6.86 to 3.70/1000 CL-days). CLABSI rate was lower in children whose caregivers completed the training (1.74/1000 CL-days, 95% CI 0.43-6.94) compared with those who did not receive any training (12.2/1000 CL-days, 95% CI 7.08-21.0, P < 0.05) or were in-training (3.96/1000 CL-days, 95% CI 1.98-7.91) at the time of infection.Caregiver training in CL management, applied within a multifaceted QI approach, reduced the rate of CLABSI in children with acute leukemia. Specific training and active involvement of caregivers in CL management may be effective to reduce CLABSI in high-risk children.

Disrupted intestinal microbiota and intestinal inflammation in children with cystic fibrosis and its restoration with Lactobacillus GG: a randomised clinical trial.

BACKGROUND & AIMS: Intestinal inflammation is a hallmark of cystic fibrosis (CF). Administration of probiotics can reduce intestinal inflammation and the incidence of pulmonary exacerbations. We investigated the composition of intestinal microbiota in children with CF and analyzed its relationship with intestinal inflammation. We also investigated the microflora structure before and after Lactobacillus GG (LGG) administration in children with CF with and without antibiotic treatment. METHODS: The intestinal microbiota were analyzed by denaturing gradient gel electrophoresis (DGGE), real-time polymerase chain reaction (RT-PCR), and fluorescence in situ hybridization (FISH). Intestinal inflammation was assessed by measuring fecal calprotectin (CLP) and rectal nitric oxide (rNO) production in children with CF as compared with healthy controls. We then carried out a small double-blind randomized clinical trial with LGG. RESULTS: Twenty-two children with CF children were enrolled in the study (median age, 7 years; range, 2-9 years). Fecal CLP and rNO levels were higher in children with CF than in healthy controls (184±146 µg/g vs. 52±46 µg/g; 18±15 vs. 2.6±1.2 µmol/L NO2 (-), respectively; P<0.01). Compared with healthy controls, children with CF had significantly different intestinal microbial core structures. The levels of Eubacterium rectale, Bacteroides uniformis, Bacteroides vulgatus, Bifidobacterium adolescentis, Bifidobacterium catenulatum, and Faecalibacterium prausnitzii were reduced in children with CF. A similar but more extreme pattern was observed in children with CF who were taking antibiotics. LGG administration reduced fecal CLP and partially restored intestinal microbiota. There was a significant correlation between reduced microbial richness and intestinal inflammation. CONCLUSIONS: CF causes qualitative and quantitative changes in intestinal microbiota, which may represent a novel therapeutic target in the treatment of CF. Administration of probiotics restored gut microbiota, supporting the efficacy of probiotics in reducing intestinal inflammation and pulmonary exacerbations. TRIAL REGISTRATION: ClinicalTrials.gov NCT 01961661.

Composition and roles of intestinal microbiota in children.

OBJECTIVE: To provide an update of the advantages of new-generation molecular diagnostics to study the diversity of intestinal microflora and to evaluate its alteration in human diseases. METHODS: We review recent advances in understanding the complex ecosystem of gut microbiota based on a dynamic and mutual interaction with the host. RESULTS: In vaginal delivery, the contact with the mother's vaginal and intestinal flora is an important source of Lactobacillus, Prevotella and other Bifidobacterium. On the opposite, in cesarean delivery, direct contact of the mouth of the newborn with vaginal and intestinal microbiota is replaced by exogenous non-maternally derived bacteria colonizing the infants' intestine producing a less diverse flora. The original microbiome settings evolve during the growth converging to three main clusters defined "enterotypes" in the adult age. CONCLUSIONS: The key role in human health could depend on the balance between beneficial and harmful microbial species populating the gut, therefore the intestinal microflora can been considered as a potential biomarker and/or therapeutic target in intestinal and extra-intestinal diseases.

Pandemic flu: a comparative evaluation of clinical, laboratory, and radiographic findings in HIV-positive and negative children.

Eleven HIV-infected and 30 otherwise healthy children hospitalized for H1N1 influenza were studied. Leukopenia was recorded in 64% of HIV-infected and in 20% of healthy children (P = 0.01). Chest radiograph was abnormal in 18 (46%) children. Interstitial pneumonia was more frequent in HIV-positive children and consolidation was more frequent in HIV-negative children. Although the duration of symptoms and hospital stay was significantly longer in HIV-negative than in HIV-positive children, only 37% of HIV-negative children and 91% of HIV-positive received oseltamivir. The H1N1 influenza attack rate was very high (20%) in HIV-infected children, but it consistently ran a mild course.

Isolated liver transplantation for treatment of liver failure secondary to intestinal failure.

Intestinal Failure is a permanent loss of digestive and absorptive functions as a consequence of short bowel syndrome and/or other primary intestinal conditions. Patients with intestinal failure (IF) require long term parenteral nutrition to survive. The only alternative to parenteral nutrition is intestinal transplantation which still entails high mortality. Children with intestinal failure on parenteral nutrition may develop liver failure (LF), as a consequence of central line infections and other conditions. In children with both irreversible IF and LF a combined transplantation is generally considered. Despite low survival rate, combined liver/intestine transplantation is associated to better intestinal graft survival and lower incidence and severity of rejection compared to isolated small bowel transplantation. Recently, isolated liver transplantation was proposed in children with IF and LF. This procedure may have a higher survival probability compared to isolated intestinal transplant, it may allow progressive weaning from PN in children in whom the remnant intestine has the potential for adaptation and offer a timely solution in children for whom intestinal graft is not immediately available. This innovative approach may prove a better option compared to combined transplantation in both the short and long term.