The utility of B-type natriuretic peptide in the diagnosis of heart failure in the emergency department: a systematic review

<p>Abstract</p> <p>Background</p> <p>Dyspnea is a common chief complaint in the emergency department (ED); differentiating heart failure (HF) from other causes can be challenging. Brain Natriuretic Peptide (BNP) is a new diagnostic test for HF for use in dyspneic patients in the ED. The purpose of this study is to systematically review the accuracy of BNP in the emergency diagnosis of HF.</p> <p>Methods</p> <p>We searched MEDLINE (1975–2005) supplemented by reference tracking. We included studies that reported the sensitivity and specificity of BNP for diagnosing HF in ED patients with acute dyspnea. Two reviewers independently assessed study quality. We pooled sensitivities and specificities within five ranges of BNP cutoffs.</p> <p>Results</p> <p>Ten studies including 3,344 participants met inclusion criteria. Quality was variable; possible verification or selection bias was common. No studies eliminated patients with obvious medical causes of dyspnea. Most studies used the Triage BNP assay; all utilized a clinical reference standard. Pooled sensitivity and specificity at a BNP cutoff of 100–105 pg/ml were 90% and 74% with negative likelihood ratio (LR) of 0.14; pooled sensitivity was 81% with specificity of 90% at cutoffs between 300 and 400 pg/ml with positive LR of 7.6.</p> <p>Conclusion</p> <p>Our analysis suggests that BNP has moderate accuracy in detecting HF in the ED. Our results suggest utilizing a BNP of less than 100 pg/ml to rule out HF and a BNP of greater than 400 pg/ml to diagnose HF. Many studies were of marginal quality, and all included patients with varying degrees of diagnostic uncertainty. Further studies focusing on patients with diagnostic uncertainty will clarify the real-world utility of BNP in the emergency management of dyspnea.</p

B cell depletion in autoimmune diabetes:insights from murine models

INTRODUCTION: The incidence of type 1 diabetes (T1D) is rising for reasons that largely elude us. New strategies aimed at halting the disease process are needed. One type of immune cell thought to contribute to T1D is the B lymphocyte. The first Phase II trial of B cell depletion in new onset T1D patients indicated that this slowed the destruction of insulin-producing pancreatic beta cells. The mechanistic basis of the beneficial effects remains unclear. AREAS COVERED: Studies of B cell depletion and deficiency in animal models of T1D. How B cells can influence T cell-dependent autoimmune diabetes in animal models. The heterogeneity of B cell populations and current evidence for the potential contribution of specific B cell subsets to diabetes, with emphasis on marginal zone B cells and B1 B cells. EXPERT OPINION: B cells can influence the T cell response to islet antigens and B cell depletion or genetic deficiency is associated with decreased insulitis in animal models. New evidence suggests that B1 cells may contribute to diabetes pathogenesis. A better understanding of the roles of individual B cell subsets in disease will permit fine-tuning of therapeutic strategies to modify these populations

Validity of Clinical Prediction Rules for Isolating Inpatients with Suspected Tuberculosis: A Systematic Review

OBJECTIVE: Declining rates of tuberculosis (TB) in the United States has resulted in a low prevalence of the disease among patients placed on respiratory isolation. The purpose of this study is to systematically review decision rules to predict the patient's risk for active pulmonary TB at the time of admission to the hospital. DATA SOURCES: We searched MEDLINE (1975 to 2003) supplemented by reference tracking. We included studies that reported the sensitivity and specificity of clinical variables for predicting pulmonary TB, used Mycobacterium TB culture as the reference standard, and included at least 50 patients. REVIEW METHOD: Two reviewers independently assessed study quality and abstracted data regarding the sensitivity and specificity of the prediction rules. RESULTS: Nine studies met inclusion criteria. These studies included 2,194 participants. Most studies found that the presence of TB risk factors, chronic symptoms, positive tuberculin skin test (TST), fever, and upper lobe abnormalities on chest radiograph were associated with TB. Positive TST and a chest radiograph consistent with TB were the predictors showing the strongest association with TB (odds ratio: 5.7 to 13.2 and 2.9 to 31.7, respectively). The sensitivity of the prediction rules for identifying patients with active pulmonary TB varied from 81% to 100%; specificity ranged from 19% to 84%. CONCLUSIONS: Our analysis suggests that clinicians can use prediction rules to identify patients with very low risk of infection among those suspected for TB on admission to the hospital, and thus reduce isolation of patients without TB