Unfriendly Fire From Neutrophils Promiscuously Potentiates Cardiovascular Inflammation

[Inflammatory indexes and their association with the severity of preeclampsia]

Background

Recent studies have confirmed the relationship between some inflammatory indexes and preeclampsia (PE); however, they have not been analyzed in PE with and without severity criteria.

Objective

To know the association between inflammatory indexes and the severity of PE.

Material and methods

Analytical cross-sectional prolective study. Pregnant patients were included, divided into group 1 (PE without severity criteria); group 2 (PE with severity criteria); group 3 (normotensive pregnant women). Records were reviewed and inflammatory indexes [(neutrophil-lymphocyte ratio [NLR], platelet-lymphocyte ratio [PLR], lymphocyte-monocyte ratio [LMR] and systemic immune index [SII]) were calculated.

Results

240 patients were analyzed, 80 per group; age 28 (IQR 27-29) years. A significant difference was observed between group 1, group 2 and group 3, NLR 3.29 (IQR 2.82-3.69), 3.59 (IQR 2.83-4.2) and 3.42 (IQR 3.17-3.92), respectively, p = 0.02; PLR 121.59 (IQR 103.78-132), 108.32 (IQR 92.96-127.43) 136 (IQR 115.18-157.56), respectively, p = 0.01; LMR and SII showed no difference between the groups. LMR made possible to distinguish PE with and without severity criteria, cut-off point of ≥ 3.20, sensitivity 56%, specificity 56%, AUC 0.56, p = 0.01, and cut-off point ≥ 3.24, sensitivity 58%, specificity 58%, AUC 0.57, p = 0.04, respectively; the LMR ≥ 3.24 was associated with PE without severity criteria (OR 2.02 [95%CI 1.08-3.80], p = 0.03).

Conclusions

The MLR was the only inflammatory index analyzed that was associated with the presence of PE without severity data. No inflammatory index was associated with PE with severity data.

Circulating Ageing Neutrophils as a Marker of Asymptomatic Polyvascular Atherosclerosis in Statin-Naïve Patients without Established Cardiovascular Disease

Background: Current data on the possible involvement of aging neutrophils in atherogenesis are limited. This study aimed to research the diagnostic value of aging neutrophils in their relation to subclinical atherosclerosis in statin-naïve patients without established atherosclerotic cardiovascular diseases (ASCVD). Methods: The study was carried out on 151 statin-naïve patients aged 40–64 years old without ASCVD. All patients underwent duplex scanning of the carotid arteries, lower limb arteries and abdominal aorta. Phenotyping and differentiation of neutrophil subpopulations were performed through flow cytometry (Navios 6/2, Beckman Coulter, USA). Results: The number of CD62L^loCXCR4^hi-neutrophils is known to be significantly higher in patients with subclinical atherosclerosis compared with patients without atherosclerosis (p = 0.006). An increase in the number of CD62L^loCXCR4^hi-neutrophils above cut-off values makes it possible to predict atherosclerosis in at least one vascular bed with sensitivity of 35.4–50.5% and specificity of 80.0–92.1%, in two vascular beds with sensitivity of 44.7–84.4% and specificity of 80.8–33.3%. Conclusion: In statin-naïve patients 40–64 years old without established ASCVD with subclinical atherosclerosis, there is an increase in circulating CD62L^loCXCR4^hi-neutrophils. It was also concluded that the increase in the number of circulating CD62L^loCXCR4^hi-neutrophils demonstrated moderate diagnostic efficiency (AUC 0.617–0.656) in relation to the detection of subclinical atherosclerosis, including polyvascular atherosclerosis.

Cholesterol Efflux Pathways Suppress Inflammasome Activation, NETosis, and Atherogenesis

BACKGROUND

The CANTOS trial (Canakinumab Antiinflammatory Thrombosis Outcome Study) showed that antagonism of interleukin (IL)-1β reduces coronary heart disease in patients with a previous myocardial infarction and evidence of systemic inflammation, indicating that pathways required for IL-1β secretion increase cardiovascular risk. IL-1β and IL-18 are produced via the NLRP3 inflammasome in myeloid cells in response to cholesterol accumulation, but mechanisms linking NLRP3 inflammasome activation to atherogenesis are unclear. The cholesterol transporters ATP binding cassette A1 and G1 (ABCA1/G1) mediate cholesterol efflux to high-density lipoprotein, and Abca1/g1 deficiency in myeloid cells leads to cholesterol accumulation.

METHODS

To interrogate mechanisms connecting inflammasome activation with atherogenesis, we used mice with myeloid Abca1/g1 deficiency and concomitant deficiency of the inflammasome components Nlrp3 or Caspase-1/11. Bone marrow from these mice was transplanted into Ldlr^-/- recipients, which were fed a Western-type diet.

RESULTS

Myeloid Abca1/g1 deficiency increased plasma IL-18 levels in Ldlr^-/- mice and induced IL-1β and IL-18 secretion in splenocytes, which was reversed by Nlrp3 or Caspase-1/11 deficiency, indicating activation of the NLRP3 inflammasome. Nlrp3 or Caspase-1/11 deficiency decreased atherosclerotic lesion size in myeloid Abca1/g1-deficient Ldlr^-/- mice. Myeloid Abca1/g1 deficiency enhanced caspase-1 cleavage not only in splenic monocytes and macrophages, but also in neutrophils, and dramatically enhanced neutrophil accumulation and neutrophil extracellular trap formation in atherosclerotic plaques, with reversal by Nlrp3 or Caspase-1/11 deficiency, suggesting that inflammasome activation promotes neutrophil recruitment and neutrophil extracellular trap formation in atherosclerotic plaques. These effects appeared to be indirectly mediated by systemic inflammation leading to activation and accumulation of neutrophils in plaques. Myeloid Abca1/g1 deficiency also activated the noncanonical inflammasome, causing increased susceptibility to lipopolysaccharide-induced mortality. Patients with Tangier disease, who carry loss-of-function mutations in ABCA1 and have increased myeloid cholesterol content, showed a marked increase in plasma IL-1β and IL-18 levels.

CONCLUSIONS

Cholesterol accumulation in myeloid cells activates the NLRP3 inflammasome, which enhances neutrophil accumulation and neutrophil extracellular trap formation in atherosclerotic plaques. Patients with Tangier disease, who have increased myeloid cholesterol content, showed markers of inflammasome activation, suggesting human relevance.