Association of monocyte CCR2 expression with obesity and insulin resistance in postmenopausal women.

PURPOSE: Monocytes actively participate in inflammatory mechanisms that contribute to the development of adipose tissue dysfunction and atherogenesis. The aim of this study was to evaluate the association of monocyte CCR2 chemokine receptor expression and intracellular oxidative burst with the metabolic and inflammatory factors related to body weight. METHODS: The study was performed in 67 postmenopausal women with normal, overweight and obese body mass index. Monocyte CCR2 surface expression and intracellular oxidative burst activity (determined using 2', 7'-dichlorofluorescin diacetate) were analyzed by flow cytometry. Serum levels of HMW adoponectin, monocyte chemoattractant protein-1 (MCP-1), insulin, glucose, lipids and C-reactive protein were determined. RESULTS: Subjects with homeostasis model assessment-estimated insulin resistance (HOMA-IR) above the median had significantly higher proportion of CCR2+ monocytes and higher mean fluorescence intensity (MFI) of CCR2 and oxidative burst. The proportion of CCR2+ monocytes and CCR2 MFI were correlated with body weight, body mass index, fat mass, insulin and HOMA-IR. Oxidative burst also correlated with anthropometric measures, fat mass and expression of CCR2. No correlations were found between these markers of monocyte activation and HMW adiponectin or monocyte chemoattractant protein-1. The absolute number of monocytes was associated with insulin and this association remained significant after adjusting for C-reactive protein. In the multiple regression model the monocyte number was determined to be an independent predictor of insulin level. CONCLUSION: These results provide support for significant associations of monocyte number and markers involved in monocyte activation with obesity and insulin resistance.

Inflammatory Gene Expression in Neck Perivascular and Subcutaneous Adipose Tissue in Men With Carotid Stenosis.

The inflammatory phenotype of neck adipose tissue (NAT) might reflect its involvement in the pathogenesis of carotid atherosclerosis. We investigated inflammatory gene expression in the subcutaneous and the perivascular (pericarotid) adipose tissue from patients with carotid stenosis (CS) undergoing endarterectomy and a control group of patients without significant carotid atherosclerosis undergoing thyroid surgery. Only male patients were included (n = 13 in each study group). Clinical and biochemical data along with serum leptin, adiponectin, and monocyte chemoattractant protein 1 (MCP-1) were collected. Adipose tissue samples were obtained from both the subcutaneous and pericarotid compartments. Real-time polymerase chain reaction was used to measure gene expression of macrophage markers and adipokines. The CS group had higher subcutaneous and pericarotid visfatin gene expression and higher pericarotid expression of MCP-1 and CD68 genes. The ratio between pericarotid CD206 and CD68 gene expression was similar between study groups. Adiponectin gene expression in both NAT compartments did not differ between groups, but it was negatively associated with body weight. These observations suggest that NAT, and especially the pericarotid compartment, express enhanced inflammatory properties in patients with CS, but the proportion of anti-inflammatory macrophages in advanced atherosclerosis seems to be maintained.

Monocytes in metabolic disorders--opportunities for flow cytometry contributions.

Chronic inflammation has arised as a major underlying cause of atherosclerosis, obesity and diabetes. It is mediated by cells of innate immune system like macrophages but also by their antecedents, circulating monocytes. Roles of monocyte subsets and different markers of monocyte activation in the context of metabolic disorders have been reviewed. Applying cell based approach through flow cytometry in this field has resulted with new understanding of pathophysiologic mechanisms. Possible implications of these insights in diagnosis, prognosis and revealing of therapeutic targets in metabolic disorders remain a challenge for future.

Flow cytometric analysis of deep-seated lymph nodes.

Flow cytometry (FC) immunophenotyping is an important tool in the evaluation of lymphadenopathy and is widely used in the diagnosis of non-Hodgkin's lymphomas (NHLs) on fine-needle aspirates of lymph nodes and extranodal sites. Because at least 80% of NHLs are of B-cell type, detection of immunoglobulin (Ig) light-chain-restriction is the most commonly used method for confirmation of monoclonality. The aim of our study was to evaluate usefulness of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) for FC analysis from deep-seated lymph nodes and to compare results of FC clonality analysis to cytomorphologic diagnosis of sampled lymph nodes. For cytological diagnosis direct smears were made, selected slide was stained for rapid-on site evaluation procedure. Sixteen patients with suspected NHL of deep-seated lymph nodes obtained by EUS-FNA were submitted for FC clonality analysis using four-color multiparameter flow cytometry stained with kappa/lambda/CD19/CD45. Clonality analysis was performed on 11 samples. Monoclonality was demonstrated in seven of 11 cases cytologically diagnosed as NHL and four of 11 cases cytologically diagnosed as benign were polyclonal. Our results show that EUS-FNAC with FC is a sensitive and specific tool in the diagnosis of deep-seated B-NHL. Cytologic diagnosis combined with FC clonality analysis can be performed in majority of cases and may eliminate need for open biopsy in some cases.

The accuracy of fine needle aspiration cytology and flow cytometry in evaluation of nodal and extranodal sites in patients with suspicion of lymphoma.

Today lymphomas are defined according to a combination of morphology, immunophenotype, genetic features and clinical presentation, so beside the pure cytomorphologic analysis in diagnosis of lymphoma ancillary techniques such as cytochemistry, immunocytochemistry, molecular diagnosis and flow cytometry (FC) are often used. Our goal was to determinate how is information given by fine-needle aspiration cytology (FNAC) and FC correlated with pathohistologic diagnosis and to evaluate ability to diagnose and subclassify malignant lymphomas by FNAC and FC. This study is a retrospective chart review of patients with suspicion of lymphoma processed at University Hospital Dubrava in Zagreb. After analysis 50 patients fulfilled inclusion criteria for this study (FNAC diagnosis with or without FC and consecutive confirmatory pathohistological diagnosis). When analyzing accuracy of FNAC according to suspicion of lymphoma or NHL and differential diagnosis lymphoma sensitivity was 97.7%, specificity 85.7% and the diagnostic accuracy was 96%. When analyzing accuracy of FNAC according to the subclassification of lymphoma, sensitivity was 74.4%, specificity 85.7% and the diagnostic accuracy 76%. Combined FNAC and FC improved sensitivity, positive predictive value, negative predictive value and diagnostic accuracy. Sensitivity was 79.1% and the diagnostic accuracy 80%. We have shown that these methods can distinguish benign lymphadenopaties from lymphomas and also subclassify lymphomas and quickly provide clinicians with that information.

Multiple metamorphoses of CD38 from prognostic marker to disease modifier to therapeutic target in chronic lymphocytic leukemia.

Human CD38, an ecto-enzyme and a receptor, performs as an independent negative prognostic marker for patients with chronic lymphocytic leukemia (CLL), a hematological malignancy characterized by the accumulation of a population of mature B lymphocytes expressing CD5. Patients with a CD38⁺ CLL clone display a more aggressive form of the disease with earlier treatment requirements and ultimately shorter overall survival than patients with a CD38⁻ clone. Several lines of evidence indicate that CD38 is not only a diagnostic marker but also a key element in the molecular network regulating disease maintenance and progression. First, CD38 is a receptor that induces proliferation and increases survival of CLL cells. Second, CD38 signals facilitate access of CLL cells to growth-favorable districts. This is achieved by enhancing i) chemotaxis towards CXCL12, ii) integrin-mediated adhesion and iii) matrix metalloprotease synthesis and secretion. Third, blocking monoclonal antibodies targeting CD38 impair CLL homing to spleen and bone marrow in xenograft models. These functions appear to be modulated by frontal interactions with CD31 as well as by lateral associations on the CLL membrane to form a large supramolecular complex similar to the invadosomes of epithelial cells. Our understanding has evolved from considering CD38 as a marker of unfavorable prognosis to recognizing its function as a disease modifier. Studies in the next few years will likely determine whether the molecule can also serve as a target for new therapies, using monoclonal antibodies, inhibitors of the enzymatic activity or both.