Circulating galectin-3 in infections and non-infectious inflammatory diseases.

Recent studies point to a dual role for galectin-3 as both a circulating damage-associated molecular pattern and a cell membrane-associated pattern recognition receptor. The aim of this study was to assess the potential of circulating galectin-3 for discriminating between infections and non-infectious inflammatory disorders on the one hand, and between fungal and bacterial infections on the other. Galectin-3 and C-reactive protein (CRP) were measured in the plasma of 127 patients with either non-infectious inflammatory disorders (gout, autoinflammatory syndrome or pancreatitis) or an infection (viral lower respiratory tract infection, bacterial sepsis or candidaemia). Circulating galectin-3 concentrations were increased in patients with infections when compared with healthy volunteers or patients with non-infectious inflammatory diseases. At cut-off values with a specificity of 95%, the sensitivity of galectin-3 (>20.6 ng/ml) to discriminate between an infection and non-infectious inflammation was higher than that of CRP (>156 mg/l): 43% [95% confidence interval (CI) 33-53%] versus 27% (95% CI 19-37%), p = 0.03. After exclusion of patients with CRP <156 mg/l, galectin-3 concentration >20.6 ng/ml could identify 41 % (95% CI 29-53%) of the patients with an infection at the cost of one false-positive with non-infectious inflammation. Using this sequential approach, 57% of the patients with an infection could be selected. Galectin-3 concentrations were similar in patients with bacterial and Candida sepsis, while being lower in viral respiratory infections. Although galectin-3 does not discriminate between bacterial and Candida sepsis, the sequential use of CRP and galectin-3 in distinguishing infectious diseases from non-infectious inflammation may be superior to CRP alone.

Specific gene expression signature associated with development of autoimmune type-I diabetes using whole-blood microarray analysis.

Understanding the pathogenesis of type-I diabetes (T1D) is hindered in humans by the long autoimmune process occurring before clinical onset and by the difficulty to study the pancreas directly. Alternatively, exploring body fluids and particularly peripheral blood can provide some insights. Indeed, circulating cells can function as 'sentinels', with subtle changes in gene expression occurring in association with disease. Therefore, we investigated the gene expression profiles of circulating blood cells using Affymetrix microarrays. Whole-blood samples from 20 first-degree relatives of T1D children with autoimmune diabetes-related antibodies, 19 children immediately after the onset of clinical T1D and 20 age- and sex-matched healthy controls were collected in PAXgene tubes. A global gene expression analysis with MDS approach allowed the discrimination of pre-diabetic subjects, diabetic patients and healthy controls. Univariate statistical analysis highlighted 107 distinct genes differently expressed between these three groups. Two major gene expression profiles were characterized, including type-I IFN-regulated genes and genes associated with biosynthesis and oxidative phosphorylation. Our results showed the presence of early functional modifications associated with T1D, which could help to understand the disease and suggest possible avenues for therapeutic interventions.

Galectin-10 mRNA is overexpressed in peripheral blood of aspirin-induced asthma.

BACKGROUND: In sensitive patients, aspirin is associated with nasal and bronchial inflammation, eliciting local symptoms. Although the disease is clinically well characterized, its physiopathology is incompletely understood and noninvasive procedures, allowing an effective distinction between aspirin-induced asthma (AIA) and aspirin-tolerant asthma (ATA) are missing. OBJECTIVES: The aims of the study were to compare AIA and ATA cohorts for clinical characteristics and to screen peripheral blood for differential mRNA expression. METHODS: Patients experiencing symptoms following aspirin ingestion were considered as aspirin sensitive. Peripheral blood was collected to quantify mRNA expression, using microarray technology and quantitative RT-PCR. RESULTS: Data indicated that AIA and ATA share large number of similarities for clinical phenotype. Screening of mRNA expression using microarray showed an overexpression of galectin-10 mRNA in AIA (AIA/ATA ratio = 1.9, P < 0.05). Results were confirmed using qRT-PCR. A positive correlation was established between microarray and qRT-PCR results for galectin-10 mRNA expression (r = 0.92, P < 0.0001). Finally, qRT-PCR results were validated on a subset of asthmatics and controls, showing an increased expression of galectin-10 mRNA in AIA vs ATA (P < 0.001) and vs controls (P < 0.01). CONCLUSIONS: Our results demonstrate that AIA and ATA remain difficult to distinguish using clinical criteria. Employing two molecular biological methods, we demonstrate that galectin-10 mRNA is overexpressed in AIA, suggesting a novel candidate gene and a potentially innovative pathway for mucosal inflammation in aspirin intolerance.

Procalcitonin and calcitonin gene-related peptide decrease LPS-induced tnf production by human circulating blood cells.

The pathogenesis of septic shock is mainly due to unregulated tumour necrosis factor-alpha (TNF-alpha) production. Procalcitonin (PCT) and calcitonin gene-related peptide (CGRP) are alternative transcription products of the calcitonin gene. Since high PCT levels have been described in human sepsis, and since CGRP inhibits TNF synthesis in rats, we examined the role of these peptides in the regulation of the inflammatory response during septic shock. LPS-induced TNF production was assessed using a human whole blood model. In this model, PCT (10(-7) M) and CGRP (10(-6) M) significantly inhibit TNF production by 27 and 24 % respectively. The effect of CGRP was reversed by CGRP 8-37 (10 microM), an antagonist of CGRP receptor. No effect on interleukin (IL)-1, IL-6 and IL-8 was found. This is the first description of an anti-inflammatory role for PCT and CGRP in humans.