Quantification of N-acetyl-l-aspartate in dried blood spots: A simple and fast LC-MS/MS neonatal screening method for the diagnosis of Canavan disease.

BACKGROUND: Canavan disease is a devastating neurometabolic disorder caused by accumulation of N acetylaspartate in brain and body fluids due to genetic defects in the aspartoacylase gene (ASPA). New gene therapies are on the horizon but will require early presymptomatic diagnosis to be fully effective. METHODS: We therefore developed a fast and highly sensitive liquid chromatography mass spectrometry (LC-MS/MS)-based method for quantification of N-acetylaspartate in dried blood spots and established reference ranges for neonates and older controls. With this test, we investigated 45 samples of 25 Canavan patients including 8 with a neonatal sample. RESULTS: Measuring N-acetylaspartate concentration in dried blood with this novel test, all Canavan patients (with variable severity) were well separated from the control group (median; range: 5.7; 1.6-13.6 µmol/L [n = 45] vs 0.44; 0.24-0.99 µmol/L [n = 59] (p < 0.05)). There was also no overlap when comparing neonatal samples of Canavan patients (7.3; 5.1-9.9 µmol/L [n = 8]) and neonatal controls (0.93; 0.4-1.8 µmol/L [n = 784]) (p < 0.05). CONCLUSIONS: We have developed a new LC-MS/MS-based screening test for early postnatal diagnosis of Canavan disease that should be further evaluated in a population-based study once a promising treatment becomes available. The method meets the general requirements of newborn screening and should be appropriate for multiplexing with other screening approaches that combine chromatographic and mass spectrometry techniques.

Reduced circulating B cells and plasma IgM levels are associated with decreased survival in sepsis - A meta-analysis.

BACKGROUND: B cell function and antibody production are crucial factors in host protection during inflammation. We aimed to synthesize the available evidence on the association between the reduction of circulating B cells and plasma immunoglobulin (IgM) levels and decreased survival during sepsis. METHODS: We performed a systematic search in PubMed, Embase, ISI Web of Knowledge, Cochrane Central Register of Controlled Trials, BioMed Central, and Science Direct. We selected studies with data on circulating B cells and plasma IgM levels within the initial 24 h after sepsis onset. RESULTS: In total nine studies (n = 992 patients) were identified. Circulating B cells were reduced in septic patients as compared to non-septic patients (mean difference [MD] -88.2 cells/µl; 95% confidence interval [CI] -148.6--27.9). Sepsis non-survivors showed a significant reduction of circulating B cells and IgM levels compared to sepsis survivors (MD -77.1 cells/µl; 95% CI -111.4--42.7 and MD -20.9 mg/dl; 95% CI -33.8--8.0, respectively). CONCLUSIONS: Our results suggest that a reduction of circulating B cells and IgM levels at sepsis onset are associated with decreased sepsis survival. However, due to methodological limitations and the risk of bias, we need further prospective studies to confirm this association. REGISTRATION: The protocol was registered (PROSPERO 2016:CRD42016053184).

Retrospective analysis on thermal injuries in children-Demographic, etiological and clinical data of German and Austrian pediatric hospitals 2006-2015-Approaching the new German burn registry.

OBJECTIVE: The purpose of this observational, multi-center study was to reveal epidemiologic, etiological and clinical aspects of hospitalized children with thermal injuries in Germany and Austria and the workup of a renewed web-based pediatric burn registry. METHODS: From 2006 to 2015, comprehensive patient data of thermally injured children in Germany and Austria were collected prospectively. Retrospective analysis of age, gender, mechanism of injury, total body surface area burned, way of admission and length of stay was performed, followed by the comparative analysis between designated burn centers and other pediatric hospitals. RESULTS: 32 hospitals participated in the study including data of 13,460 thermally injured hospitalized children. The majority was 12-<36 months of age with a share of 48%. 56.5% were boys. The most frequent cause of injury was scalding representing 74.4%. Designated pediatric burn centers treated 82.2% of all patients. In relation to non-centers, no significant differences were seen concerning the affected total body surface area and the amount of patients <1 year of age in contrast to a significant difference regarding the amount of fire injuries, all being parameters indicating the severity of thermal injuries. Overall mortality was 0.1%. CONCLUSION: This study extends our knowledge about population characterization of thermally injured children, highlights risk factors and serves as a basis for the renewed pediatric burn registry from 2016 on.

Analysis of circulating plasmacytoid dendritic cells during the course of sepsis.

BACKGROUND: Sepsis is characterized as a biphasic immune reaction in response to invading micro-organisms causing a life-threatening condition. This reaction is triggered by the activation of many different immune cells causing a dramatic inflammatory response often followed by immunosuppression. The balance of the immune response in this complex interplay of pro- and anti-inflammatory processes is crucial for the course of sepsis and host survival. For a better understanding of the involved mechanisms, a precise knowledge of participating immune cells in a timely manner is necessary. METHODS: We analyzed circulating plasmacytoid dendritic cells (pDCs) by using multicolor, flow cytometric analysis in septic patients over 28 days. In addition, we assessed disease severity, organ failure, and outcome in these septic patients. RESULTS: The numbers of circulating pDCs started to increase at day 1 after the onset of sepsis and were greatly increased from day 4 after sepsis onset. At days 7 and 14, the numbers of circulating pDCs peaked and returned to normal values at day 28 after the onset of sepsis. These changes were accompanied by increased expression of CD11b, which is known as crucial factor for transendothelial migration. In addition, the circulating pDCs in nonsurvivors showed greatly decreased values compared with survivors over the course of sepsis. CONCLUSION: The results presented here support the concept that circulating pDCs might have an important role in the immune response during sepsis and might function as an early predictive biomarker for the outcome of sepsis.

Interleukin-3 amplifies acute inflammation and is a potential therapeutic target in sepsis.

Sepsis is a frequently fatal condition characterized by an uncontrolled and harmful host reaction to microbial infection. Despite the prevalence and severity of sepsis, we lack a fundamental grasp of its pathophysiology. Here we report that the cytokine interleukin-3 (IL-3) potentiates inflammation in sepsis. Using a mouse model of abdominal sepsis, we showed that innate response activator B cells produce IL-3, which induces myelopoiesis of Ly-6C(high) monocytes and neutrophils and fuels a cytokine storm. IL-3 deficiency protects mice against sepsis. In humans with sepsis, high plasma IL-3 levels are associated with high mortality even after adjusting for prognostic indicators. This study deepens our understanding of immune activation, identifies IL-3 as an orchestrator of emergency myelopoiesis, and reveals a new therapeutic target for treating sepsis.