Abdominal adipose tissue predicts major cardiovascular events in systemic necrotising vasculitides

OBJECTIVES

Cardiovascular (CV) events are highly prevalent in systemic necrotising vasculitides (SNV). Visceral/subcutaneous adipose tissue (VAT/SAT) ratio has been shown to be associated with CV events in various diseases. We aimed to assess the relevance of abdominal adipose tissue measurement to predict major CV events (MCVEs) in SNV.

METHODS

Patients with SNV were successively included in a longitudinal study assessing MCVEs and other sequelae. Dual x-ray absorptiometry was performed to evaluate abdominal adipose tissue. Patients were prospectively followed for MCVEs, defined as myocardial infarction, unstable angina, stroke, arterial revascularisation and/or hospitalisation for or death from CV causes.

RESULTS

One hundred and twenty consecutive SNV patients were included and analysed (54 males, mean age 53±18 years). High CV risk was found in 28 (23.3%) patients. In univariate analysis, age, male gender, VDI, VAT/SAT ratio and serum troponin level were significantly associated with high CV risk, whereas age and VAT/SAT ratio remained independently associated with high CV risk. Variables associated with high tertile of VAT/SAT ratio included age and metabolic risk factors. After median follow-up of 42 months, 19 (16%) patients experienced MCVEs. Hazard ratios for incident MCVEs compared with 1st tertile of VAT/SAT ratio were 7.22 (1.02-51.3; p=0.048) and 9.90 (3.15-31.2; p=0.0002) in the 2nd and 3rd tertile, respectively.

CONCLUSIONS

Abdominal visceral adipose tissue is a reliable surrogate marker of CV risk and predicts incident MCVEs in SNV patients. Abdominal adipose tissue should be probably evaluated routinely in these patients to assess CV risk.

[System of microcirculation, markers of vascular wall damage and systematicity of the process in rheumatic diseases]

The work was aimed at studying the interrelationship of the microcirculation system and the parameters of endothelial activation with markers of inflammatory process activity in rheumatic diseases (RD). We carried out a comprehensive examination of a total of 330 patients presenting with systemic diseases of connective tissue (SDCT), rheumatoid arthritis (RA) and systemic vasculitis (SV). Studying microcirculation included impregnation of filmy preparations according to the V.V. Kupriyanov technique and biomicroscopy of the conjunctiva of the eyeball. We also determined markers of endothelial activation and lesion of vascular wall, indices of activity of rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) and vasculitis clinical activity index (VCAI), common carotid artery intima-media thickness (CCA-IMT), biopsy materials of the musculocutaneous flap, of the operational and autopsy materials. Determining the indices of microcirculation showed that first of all the process involves postcapillaries and venules which are dilated, becoming tortuous, with the formation of microaneurysms and stellate venules. Capillaries, postcapillaries and venules were found to contain parietally located small-grained conglomerates of blood platelets and thrombocytic masses plugging up the lumens of microvessels. Intravascular alterations were characterized by the presence of erythrocyte aggregates, stases, microthrombovasculitis, «sludge» phenomenon, and a decrease in capillary blood flow. Extravascular changes included perivascular haemorrhages. In arterioles and precapillaries the inflammatory process manifested itself by swelling, dystrophy and desquamation of endothelial cells, plasmatic impregnation of the walls, luminal thrombosis followed by the development of severe sclerosis and glialinosis. The morphological study showed the presence of destructive alterations in the vascular wall, fibrinoid necrosis, and infiltration-proliferative cellular reaction. The most pronounced changes in the autoimmune inflammation markers had place in RA and systemic lupus erythematosus (SLE). We revealed increased indices of inflammatory process activity such as interleukin-8, C-reactive protein (CRP). We also revealed the signs of endothelial dysfunction, manifesting itself as a statistically significant (p<0.01) increase in concentrations of the soluble vascular cell adhesion molecule (sVCAM-1), von Willebrand factor antigen (VWFA), the number of desquamated endotheliocytes (DE). Also observed was a clear-cut dependence of the level of endothelial activation markers from the degree of the processes activity. We revealed a positive correlation between the level of CRP, IgG RF, the level of sVCAM-1 and the number of DE. The levels of interleukin-8, sVCAM-1 and VWFA were elevated in patients with RD. Increased activity of the disease was accompanied by impairments at the level of the microcirculatory bed, an increase in the concentration of inflammation markers and indices of endothelial dysfunction.

Role and interactions of annexin A1 and oestrogens in the manifestation of sexual dimorphisms in cerebral and systemic inflammation

BACKGROUND AND PURPOSE

Gender differences in inflammation are well described, with females often showing more robust, oestrogen-associated responses. Here, we investigated the influence of gender, oestrogen and the anti-inflammatory protein annexin A1 (AnxA1) on lipopolysaccharide (LPS)-induced leukocyte-endothelial cell interactions in murine cerebral and mesenteric microvascular beds.

EXPERIMENTAL APPROACH

Intravital microscopy was used to visualize and quantify the effects of LPS (10 μg·per mouse i.p.) on leukocyte-endothelial interactions in male and female wild-type (WT) mice. The effects of ovariectomy ± oestrogen replacement were examined in WT and AnxA1-null (AnxA1(-/-) ) female mice.

KEY RESULTS

LPS increased leukocyte adherence in the cerebral and mesenteric beds of both male and female WT mice; females showed exacerbated responses in the brain versus males, but not the mesentery. Ovariectomy further enhanced LPS-induced adhesion in the brain but not the mesentery; its effects were reversed by oestrogen treatment. OVX AnxA1(-/-) mice also showed exaggerated adhesive responses to LPS in the brain. However, these were unresponsive to ovariectomy and, paradoxically, responded to oestrogen with a pronounced increase in basal and LPS-induced leukocyte adhesion in the cerebrovasculature.

CONCLUSIONS AND IMPLICATIONS

Our data confirm the fundamental role of AnxA1 in limiting the inflammatory response in the central and peripheral microvasculature. They also (i) show that oestrogen acts via an AnxA1-dependent mechanism to protect the cerebral, but not the mesenteric, vasculature from the damaging effects of LPS and (ii) reveal a paradoxical and potentially toxic effect of the steroid in potentiating the central response to LPS in the absence of AnxA1.