Leukocyte cell population data (volume conductivity scatter) in postprandial leukocyte activation.

INTRODUCTION: Changes in leukocyte cell population data have been reported in various infectious diseases, but little is known in other inflammatory conditions such as the postprandial state. We investigated whether leukocyte cell population data change during postprandial leukocyte activation. METHODS: Healthy volunteers underwent a standardized oral fat loading test (OFLT). Flowcytometric quantitation of leukocyte activation markers CD11b, CD66b, CD35, and CD36, together with leukocyte cell population data from LH750 hematology analyzers were measured fasting and at 4 and 8 h postprandially. RESULTS: Twelve volunteers were included. Postprandial leukocyte activation was confirmed by increased expression of CD11b by monocytes (+11.7%) and neutrophils (+15.0%) and by increased expression of CD66b (+14.7%) and CD35 (+16.6%) by neutrophils at T = 4 h. The mean scatter from neutrophils, reflecting granularity, significantly decreased at T = 4 h (P < 0.05) and returned to baseline at T = 8 h (P-anova 0.048). The mean volume of monocytes increased significantly at T = 4 h (P < 0.001) and returned to baseline at T = 8 h (P-anova 0.0008). At T = 4 h, CD11b expression on neutrophils was associated with a reduction in mean scatter of neutrophils (Pearson's r: -0.677, P = 0.016). CONCLUSION: Postprandial leukocyte activation is accompanied by temporary changes in leukocyte cell population data, similar to changes observed during various infections, but to a lesser extent.

Metformin: a cheap and well-tolerated drug that provides benefits for viral infections.

OBJECTIVES: Insulin resistance in viral infections is common. We have explored the effectiveness of metformin for alleviating insulin resistance in HIV-infected patients and assessed the relevance of the ataxia-telangiectasia mutated (ATM) rs11212617 variant in the clinical response with the rationale that metformin modulates cellular bioenergetics in an ATM-dependent process. METHODS: HIV-infected patients (n = 385) were compared with controls recruited from the general population (n = 300) with respect to the genotype distribution of the ATM rs11212617 variant and its influence on selected metabolic and inflammatory variables. We also followed up a subset of male patients with HIV and hepatitis C virus (HCV) coinfection (n = 47) who were not receiving antiviral treatment and for whom metformin was prescribed for insulin resistance, which tends to have a higher incidence and severity in coinfected patients. RESULTS: Among the HIV-infected patients, human cytomegalovirus (91.9%) and HCV (62.3%) coinfections were frequent. Selected metabolic and/or inflammatory variables were significantly altered in infected patients. Treatment with metformin in HIV and HCV coinfected patients was well tolerated and significantly increased the sensitivity of peripheral tissues to insulin. The minor allele (C) of the rs11212617 variant was associated with treatment success and may affect the course of insulin resistance in response to metformin (odds ratio 1.21; 95% confidence interval 1.07-1.39; P = 0.005). There were no differences between treated and untreated patients in viral loads or variables measuring immune defence, indicating that toxicity is unlikely. CONCLUSIONS: We provide novel data suggesting that identification of the ATM rs11212617 variant may be important in assessing the glycaemic response to metformin treatment for insulin resistance in HIV-infected patients.

The role of combined assessment of defense against oxidative stress and inflammation in the evaluation of peripheral arterial disease.

Atherosclerosis in symptomatic peripheral arterial disease affects wide portions of numerous arteries in lower extremities. The resulting active inflammation in a considerable amount of arterial tissue facilitates systemic detection via measurement of inflammation-related variables. We reasoned that the combined assessment of defense against oxidative stress, in the form of paraoxonase-1 (PON1), and monocyte migration measured as circulating (C-C motif) ligand 2 (CCL2), may play a role in the evaluation of these patients. Plasma CCL2 and serum PON1-related variables, assessed by their interaction with functional genetic variants, were measured in a cross-sectional study in patients with symptomatic PAD. We found that PON1 activity and concentration were significantly lower and CCL2 concentration higher in PAD patients compared to controls, that the combination of plasma CCL2 and PON1- related values, especially PON1 concentration differentiated, almost perfectly, controls from patients and that the expression of CCL2 and PON1 generally co-localized in the atherosclerotic lesion. Since no association with genetic variants was found, such a relationship is probably the result of the disease. Our data suggest a coordinated role between CCL2 and PON1 that may be detected in blood with simple measurements and may represent an indicator of the extent of atherosclerosis.

Pitfalls in measuring high-density lipoprotein cholesterol concentrations in HIV-infected patients.

OBJECTIVES: HIV infection and its treatment are associated with dyslipidaemia and increased risk of cardiovascular disease. Accurate high-density lipoprotein (HDL) cholesterol values are necessary for the management of these abnormalities, but current methods have not been properly assessed in these patients. The aim of this study was to assess in HIV-infected patients the consistency and accuracy of a synthetic polymer/detergent homogeneous assay used to measure HDL cholesterol concentrations and to evaluate the impact of storage. METHODS: HDL cholesterol was measured using a synthetic polymer/detergent homogeneous method in samples from HIV-infected patients and healthy subjects for each of the storage regimens: baseline, after 1 week at 4 degrees C, and after 12 months at -80 degrees C. The ultracentrifugation and precipitation assays were used for comparison. RESULTS: Three out of every 20 samples from HIV-infected patients had discrepant HDL cholesterol values with respect to the ultracentrifugation method. Overestimation was associated with high C-reactive protein concentrations and underestimation with plasma gamma-globulin concentrations, an effect that was amplified by any of the storage conditions tested. CONCLUSIONS: Caution is needed when using the synthetic polymer/detergent homogeneous method for direct measurement of HDL cholesterol concentrations in HIV-infected patients. This assay is of limited use in clinical trials in which frozen samples are analysed.