Pediatric Anaerobic Blood Culture Practices in Industrialized Countries.

BACKGROUND: Routine anaerobic blood culture collection in febrile children is controversial, as clinicians try to account for the severe but relative infrequency of anaerobic bacteremia. Furthermore, clinical and laboratory practice variation among institutions may lead to potentially inaccurate epidemiological data. Our goal was to assess blood culture practices in pediatric patients throughout an international network of hospitals in industrialized countries. METHODS: We conducted a survey of current clinical and laboratory practice patterns in a convenience sample of international institutions participating in 6 pediatric emergency research networks in the US, Canada, Europe, Australia, and New Zealand. A lead clinician at each institution queried institutional practices from the emergency department, pediatric intensive care unit, and oncology medical directors. The microbiology director at each institution completed the laboratory survey. RESULTS: Sixty-five of 160 (41%) invited institutions participated in the survey. Routine anaerobic blood cultures are collected in 30% of emergency departments, 30% of intensive care units, and 48% of oncology wards. Reasons for restricting anaerobic culture collection included concerns regarding blood volume (51%), low pretest probability (22%), and cost-effectiveness (16%). The most common reasons institutions allow for selectively obtaining anaerobic cultures are clinical suspicion (64%) and patients who are immunosuppressed (50%). The microbiology survey showed variation in systems, although most use the BACTEC™ culture system and MALDI-TOF for organism identification. CONCLUSIONS: There is broad variation in anaerobic blood culture practices among a network of pediatric hospitals in industrialized countries.

Does clinically relevant temperature change miRNA and cytokine expression in whole blood?

Unintentional hypothermia is a well-described risk factor for death and complications after elective and emergency surgery. The molecular mechanisms by which hypothermia exerts its detrimental effects are not well understood. Differences in cytokine production and the overall cell function have been reported under hypothermic conditions. We investigated the effect of a range of clinically relevant temperatures on cytokine production and microRNA (miRNA) expression in a whole-blood model. We found that there was a wide variation in tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and IL-10 production among different subjects, ranging from low to high TNF-α producers. The intersubject variation can also be found on the transcriptional level: high producers had higher upregulation of TNF-α messenger RNA than intermediate and low producers. This variation in TNF-α was reproducible in each individual. Temperature seems to modulate TNF-α production among these different groups. miRNA expression was modulated by temperature. miRNA-181a might control, or be a part of the mechanism which controls, TNF-α production. However, an analysis of whole-leukocyte RNA does not allow the investigation of mechanisms in a specific leukocyte subpopulation such as monocytes, because these changes may be concealed by miRNA expression changes in the other leukocyte subsets. In conclusion, TNF-α, IL-6, and IL-10 production is highly variable among different persons, but temperature affects the expression of miRNAs, which may consequently alter the production of TNF-α.

Crohn's disease in Caucasians and African Americans, as defined by clinical predictors and single nucleotide polymorphisms.

OBJECTIVES: To compare three aspects of Crohn's disease (CD) between African Americans and Caucasians: (1) demographic data and environmental factors affecting CD susceptibility, (2) disease presentation and clinical course, and (3) genetic susceptibility via the use of single nucleotide polymorphism (SNP) data for inflammatory bowel disease (IBD) susceptibility loci. METHODS: Clinical data and peripheral blood were obtained from 1032 patients (554 CD patients and 478 controls) derived from a clinically well-defined university-based medical and surgical digestive disease practice and included those who were diagnosed with IBD. Genomic DNA was extracted and polymerase chain reaction (PCR) amplification and genotyping were performed for 11 SNPs, including the NOD2, IL-23r, OCTN 1, and the IGR gene variants. RESULTS: A total of 554 patients with CD were included in this study: 53 African Americans (10%), 485 Caucasians (87%), and 15 of other races (3%). The strongest demographic predictor of CD in African American patients was a family history of IBD. Ileocolic disease (L3) was the most common site involved in both African Americans and Caucasians, while the penetrating phenotype (B3) was the most common CD disease behavior in both races. Genotype association analysis showed a significant association between 2 IL23r gene SNPs and CD susceptibility in African Americans (p = .016 and .028, respectively). CONCLUSION: We believe this study is the first to report on genotype-phenotype associations in African American CD patients and compare findings to Caucasian CD patients within the same geographic area. We found no association between NOD2 gene SNPs and CD susceptibility in African Americans patients (p > .05).