A prospective multicenter evaluation of direct molecular detection of blood stream infection from a clinical perspective.

BACKGROUND: Rapid diagnosis and appropriate antimicrobial therapy are of major importance to decrease morbidity and mortality in patients with blood stream infections (BSI). Blood culture, the current gold standard for detecting bacteria in blood, requires at least 24-48 hours and has limited sensitivity if obtained during antibiotic treatment of the patient. The aim of this prospective multicenter study was to clinically evaluate the application of a commercial universal 16S/18S rDNA PCR, SepsiTest™ (PCR-ST), directly on whole blood. METHODS: In total 236 samples from 166 patients with suspected sepsis were included in the study. PCR-ST results were compared to blood culture, the current gold standard for detecting BSI. Because blood cultures can give false-negative results, we performed an additional analysis to interpret the likelihood of bloodstream infection by using an evaluation based on clinical diagnosis, other diagnostic tests and laboratory parameters. RESULTS: Clinical interpretation of results defined the detected organism to be contaminants in 22 of 43 positive blood cultures (51.2 %) and 21 of 47 positive PCR-ST results (44.7 %). Excluding these contaminants resulted in an overall sensitivity and specificity of the PCR-ST of 66.7 and 94.4 % respectively. Of the 36 clinically relevant samples, 11 BSI were detected with both techniques, 15 BSI were detected with PCR-ST only and 10 with blood culture only. Therefore, in this study, SepsiTest™ detected an additional 71 % BSI compared to blood culture alone. CONCLUSIONS: More clinically relevant BSI were diagnosed by molecular detection, which might influence patient treatment. An improved SepsiTest™ assay suited for routine use can have additional value to blood culture in diagnosing bacteremia in septic patients.

[Double blind placebo controlled cow's milk provocation for the diagnosis of cow's milk allergy in infants and children]. / Dubbelblinde placebogecontroleerde koemelkprovocatie voor de diagnostiek van koemelkallergie bij zuigelingen en kinderen.

OBJECTIVE: To test a protocol for a double-blind placebo-controlled cow's milk provocation for the diagnosis of acute allergic reactions to milk in an outpatient setting. DESIGN: Prospective, descriptive. METHOD: During the period from June 1, 1999 to February 28, 2001 the protocol was tested on all infants and children who were referred to the Paediatric outpatient clinic of the University Medical Centre on Utrecht with symptoms indicative of cow's milk allergy. The protocol comprised of a phased administration of two test meals, one with a true feed and one with placebo, during the course of one day. In case of allergic symptoms the test was discontinued and the code was broken. A diagnosis of 'cow's milk allergy' was made if the symptoms appeared during the provocation with true feeding. RESULTS: The test group (n = 154) consisted of 85 boys and 69 girls with ages ranging from 0.25 to 14 years (median 1.5). Acute type reactions to cow's milk occurred in 21 of the children who underwent the provocation. These reactions mainly consisted of cutaneous symptoms (erythema and urticaria). In none of these cases the symptoms were severe enough to require a prolonged stay in the hospital. There were no reactions on placebo meals nor acute reactions during the reintroduction of milk at home. CONCLUSION: It is possible to perform double-blind placebo-controlled provocations routinely in the diagnostic work-up of children with a suspicion of cow's milk allergy.

Differences in antigen-specific T-cell responses between infants with atopic dermatitis with and without cow's milk allergy: relevance of TH2 cytokines.

BACKGROUND: Cow's milk is the most important food antigen in infancy and may lead to acute cutaneous symptoms and atopic dermatitis (AD). The role of circulating allergen-specific T cells in the pathogenesis of food-allergic skin symptoms is still under investigation. OBJECTIVE: This study was designed to analyze the cow's milk protein (CMP)-specific T-cell response at the clonal level in infants with AD and cow's milk allergy (CMA) in comparison with infants with AD without CMA. METHODS: We used an antigen-specific culturing system with autologous B cells as antigen-presenting cells to establish CMP-specific T-cell clones derived from PBMCs in infants with AD. T-cell reactivity, measured by using a lymphocyte stimulation test, and cytokine production, measured by using ELISA, was compared between infants with AD with and without CMA. RESULTS: Both infants with and without allergy to cow's milk had a CMP-specific T helper cell response directed against the major proteins in milk. Analysis of antigen-specific cytokine production showed that this response was T(H)2 skewed in infants with CMA, with production of high levels of IL-4, IL-5, and IL-13. In contrast, infants without CMA had a T(H)1-skewed response, with high levels of IFN-gamma and low levels of IL-4, IL-5, and IL-13. CONCLUSION: These data confirm for the first time at the clonal level that food allergy in infants with AD is associated with production of T(H)2 cytokines by circulating antigen-specific CD4(+) T cells, whereas tolerance to food antigens is associated with low levels of these cytokines. This suggests a key role for the T helper cell-derived T(H)2 cytokines in food allergy-related skin symptoms.

Neurological morbidity after fetal supraventricular tachyarrhythmia.

BACKGROUND: Fetal tachyarrhythmia is a well-documented entity which, in the absence of pharmacological intervention, may lead to congestive heart failure, fetal hydrops and eventually fetal demise. The success rate of the implemented treatment is generally measured by survival and achievement of control of the arrhythmia. We report on the occurrence of associated cerebral damage in three patients with fetal tachycardia. METHODS: We describe three patients with a history of fetal supraventricular tachyarrhythmia who developed cerebral complications in utero. RESULTS: Two patients had cerebral hypoxic-ischemic lesions and one had hemorrhagic lesions present at birth. They had developed severe congestive heart failure and fetal hydrops secondary to fetal tachyarrhythmia, and there were no other obvious causes for the cerebral pathology. Two of these patients were referred to us antenatally. Therapy was instituted and resulted in control of the tachycardia and resolution of hydrops. The third patient was referred to our clinic shortly after birth because of severe circulatory problems secondary to fetal tachyarrhythmia. CONCLUSION: From these observations, we believe that a fetus with tachyarrhythmia and subsequent hydrops is at increased risk for the development of cerebral complications, due to the circulatory disturbances and sudden changes in heart rate which may lead to fluctuations in cerebral perfusion. This would imply that it is of the utmost importance to aim at immediate and complete control of the heart rate in the treatment of fetal tachyarrhythmia.