The relationship between coronary collateral circulation and neutrophil/lymphocyte ratio in patients with coronary chronic total occlusion

OBJECTIVES

To investigate the relationship between neutrophil/lymphocyte ratio (NLR) and coronary collateral circulation (CCC) in patients with coronary chronic total occlusion.

SUBJECTS AND METHODS

Our study population consisted of 275 consecutive patients with chronic total occlusion. One hundred and thirty-eight patients with chronic total occlusion were included in the study. They were classified into 2 groups as follows: impaired CCC (group 1: Rentrop grades 0-1) and good CCC (group 2: Rentrop grades 2-3). The NLR was calculated from the complete blood count.

RESULTS

The NLR values of the patients with impaired CCC (4.5 ± 0.7) were significantly higher than of those with good CCC (2.7 ± 0.6, p < 0.001). In the multivariate logistic regression test, NLR (OR 33.36, 95% CI 8.189-135.7, p < 0.001), high-sensitivity C-reactive protein (hs-CRP; OR 2.152, 95% CI 1.226-3.777, p = 0.008), estimated glomerular filtration rate (OR 1.167, 95% CI 1.049-1.298, p = 0.004) and systolic blood pressure (OR 1.068, 95% CI 1.009-1.1310, p = 0.025) were independent predictors of impaired CCC. The NLR value >3.55 yielded an area under the curve value of 0.957 (95% CI 0.921-0.992, p < 0.001) and demonstrated a sensitivity of 95% and a specificity of 90% for the prediction of CCC. A moderate correlation between NLR and hs-CRP was observed (r = 0.443; p < 0.001).

CONCLUSION

Our findings reveal that NLR correlates with the impaired development of coronary collaterals.

Natural Killer Cells and CD4 + T-Cells Modulate Collateral Artery Development

Objective— The immune system is thought to play a crucial role in regulating collateral circulation (arteriogenesis), a vital compensatory mechanism in patients with arterial obstructive disease. Here, we studied the role of lymphocytes in a murine model of hindlimb ischemia.

Methods and Results— Lymphocytes, detected with markers for NK1.1, CD3, and CD4, invaded the collateral vessel wall. Arteriogenesis was impaired in C57BL/6 mice depleted for Natural Killer (NK)-cells by anti-NK1.1 antibodies and in NK-cell–deficient transgenic mice. Arteriogenesis was, however, unaffected in Jα281-knockout mice that lack NK1.1 + Natural Killer T (NKT)-cells, indicating that NK-cells, rather than NKT-cells, are involved in arteriogenesis. Furthermore, arteriogenesis was impaired in C57BL/6 mice depleted for CD4 + T-lymphocytes by anti-CD4 antibodies, and in major histocompatibility complex (MHC)-class-II–deficient mice that more selectively lack mature peripheral CD4 + T-lymphocytes. This impairment was even more profound in anti-NK1.1-treated MHC-class-II–deficient mice that lack both NK- and CD4 + T-lymphocytes. Finally, collateral growth was severely reduced in BALB/c as compared with C57BL/6 mice, 2 strains with different bias in immune responsiveness.

Conclusions— These data show that both NK-cells and CD4 + T-cells modulate arteriogenesis. Promoting lymphocyte activation may represent a promising method to treat ischemic disease.

CD8+ T lymphocytes regulate the arteriogenic response to ischemia by infiltrating the site of collateral vessel development and recruiting CD4+ mononuclear cells through the expression of interleukin-16

BACKGROUND

Previous studies have demonstrated that macrophages and CD4+ T lymphocytes play pivotal roles in collateral development. Indirect evidence suggests that CD8+ T cells also play a role. Thus, after acute cerebral ischemia, CD8+ T cells infiltrate the perivascular space and secrete interleukin-16 (IL-16), a potent chemoattractant for monocytes and CD4+ T cells. We tested whether CD8+ T lymphocytes contribute to collateral vessel development and whether the lack of circulating CD8+ T cells prevents IL-16 expression, impairs CD4+ mononuclear cell recruitment, and reduces collateral vessel growth after femoral artery ligation in CD8(-/-) mice.

METHODS AND RESULTS

After surgical excision of the femoral artery, laser Doppler perfusion imaging demonstrated reduced blood flow recovery in CD8(-/-) mice compared with C57/BL6 mice (ischemic/nonischemic limb at day 28, 0.66+/-0.04 versus 0.87+/-0.04, respectively; P<0.01). This resulted in greater calf muscle atrophy (mean fiber area, 785+/-68 versus 1067+/-69 microm2, respectively; P<0.01) and increased fibrotic tissue content (10.8+/-1.2% versus 7+/-1%, respectively; P<0.01). Moreover, CD8(-/-) mice displayed reduced IL-16 expression and decreased CD4+ T-cell recruitment at the site of collateral vessel development. Exogenous CD8+ T cells, infused into CD8(-/-) mice immediately after femoral artery ligation, selectively homed to the ischemic hind limb and expressed IL-16. The restoration of IL-16 expression resulted in significant CD4+ mononuclear cell infiltration of the ischemic limb, faster blood flow recovery, and reduced hindlimb muscle atrophy/fibrosis. When exogenous CD8+ T cells deficient in IL-16 (IL-16(-/-)) were infused into CD8(-/-) mice immediately after femoral artery ligation, they selectively homed to the ischemic hind limb but were unable to recruit CD4+ mononuclear cells and did not improve blood flow recovery.

CONCLUSIONS

These results demonstrate that CD8+ T cells importantly contribute to the early phase of collateral development. After femoral artery ligation, CD8+ T cells infiltrate the site of collateral vessel growth and recruit CD4+ mononuclear cells through the expression of IL-16. Our study provides further evidence of the significant role of the immune system in modulating collateral development in response to peripheral ischemia.

Leukocyte subpopulations and arteriogenesis: Specific role of monocytes, lymphocytes and granulocytes

OBJECTIVE

Circulating leukocytes play a crucial role during arteriogenesis. However, known pro-arteriogenic compounds (MCP-1, GM-CSF) acting via monocytic pathways also exert positive effects on granulocytes and lymphocytes. The role of these two cell types in arteriogenesis remains yet to be clarified, which was the aim of the current study.

METHODS

Ninety New Zealand White Rabbits received either phosphate buffered saline (PBS), monocyte chemoattractant protein-1 (MCP-1), interleukin-8 (IL-8), neutrophil activating protein-2 (NAP-2) or lymphotactin (Ltn) via osmotic minipumps after unilateral femoral artery ligation. In vitro stimulation and in vivo assessment of chemoattraction confirmed cell-specific action of the compounds in rabbits. Arteriogenesis was evaluated by angiography and collateral conductance measurements using fluorescent microspheres. Quantitative immunohistology was used to quantify transmigrated leukocyte subtypes after infusion of the factors.

RESULTS

MCP-1 infusion attracts monocytes and granulocytes, whereas IL-8 attracts all three cell types albeit monocytes to a significantly lower degree than MCP-1. NAP-2 and lymphotactin selectively attract granulocytes, respectively, lymphocytes. Of the tested cytokines, only MCP-1 stimulates arteriogenesis, as assessed by collateral conductance measurements ((ml/(min 100 mmHg)): PBS, 50.70+/-5.15; MCP-1, 216.30+/-12.30; IL-8, 58.91+/-5.56; NAP-2, 66.83+/-8.72; Ltn, 52.80+/-5.37) and angiographic findings.

CONCLUSION

This study for the first time provides evidence that not granulocytes or T-lymphocytes but monocytes are the key mediators of arteriogenesis.

Impaired arteriogenic response to acute hindlimb ischemia in CD4-knockout mice

BACKGROUND

T lymphocytes, components of the immune and inflammatory systems, are involved in such normal processes as wound healing and host defense against infection and in such pathological processes as tumor growth and atherosclerotic plaque development. Angiogenesis is a mechanism common to each. Because CD4+ T lymphocytes are active in regulating humoral and cellular responses of the immune system, we determined whether CD4+ cells contribute to collateral vessel development by using the mouse ischemic hindlimb model.

METHODS AND RESULTS

One week after ischemia, CD4-/- mice showed reduced collateral flow induction, macrophage number, and vascular endothelial growth factor levels in the ischemic muscle compared with wild-type mice. There was also delayed recovery of hindlimb function and increased muscle atrophy/fibrosis. Spleen-derived purified CD4+ T cells infused into CD4-/- mice selectively localized to the ischemic limb and significantly increased collateral flow as well as macrophage number and vascular endothelial growth factor levels in the ischemic muscle. Muscle function and damage also improved.

CONCLUSIONS

These results indicate an important role of CD4+ cells in collateral development, as demonstrated by a 25% decrease in blood flow recovery after femoral artery ligation. Our data also suggest that CD4+ T cells control the arteriogenic response to acute hindlimb ischemia, at least in part, by recruiting macrophages to the site of active collateral artery formation, which in turn triggers the development of collaterals through the synthesis of arteriogenic cytokines.