Elevated blood neutrophil to lymphocyte ratio in older adults with cognitive impairment

BackgroundPrevious studies have assessed the association of neutrophil to lymphocyte ratio (NLR) with cognitive impairment (COI) in clinical settings. Whether NLR is associated with COI among free-living seniors at population level remains unknown.ObjectivesWe aimed to assess the relationship between NLR and COI among community-dwelling older adults and the predictive value of NLR for COI screening in the community.MethodsData of 4579 older adults aged 60 or older in Weitang Geriatric Diseases study, a community-based cross-sectional study conducted in Suzhou located in the east part of China, were analyzed. The NLR was calculated as the absolute neutrophil count divided by the absolute lymphocyte count. Cognitive function of the participants was assessed using the Abbreviated Mental Test.ResultsCompared to those in the first quartile of NLR, older adults in the 4th quartile of NLR had a greater risk of COI (odds ratio = 1.34, 95 % confidence interval = 1.06–1.69). Elevated NLR quartile was associated with increasing risk of COI (p value for trend = 0.02). Addition of NLR to the conventional risk factors model could improve the correct reclassification of COI about 9.0 % (p = 0.02) and integrated discrimination improvement value was 0.0012 (p = 0.09).ConclusionsWe found that elevated NLR was associated with an increased risk of COI and whether NLR may act as a clinically relevant predictor for COI among community-dwelling older adults could not be determined.     

Neutrophil to lymphocyte ratio in relation to risk of all-cause mortality and cardiovascular events among patients undergoing angiography or cardiac revascularization: A meta-analysis of observational studies

Objective

The aim of this study was to investigate whether neutrophil to lymphocyte ratio (NLR) was an independent predictor for all-cause mortality or cardiovascular events in patients undergoing angiography or cardiac revascularization with observational studies by meta-analysis.

Methods

Pubmed and Embase were searched without language restrictions for cohort studies published prior to November 2013. Citations were independently screened by 2 authors, and those meeting the inclusion criteria defined a priori were retained. Data on authors, year of publication, location, target participant, comparison of NLR, outcome assessment, number of event and sample size, duration and statistical adjustments were abstracted.

Results

Eight studies were identified that reported on all-cause mortality and five studies were identified that reported on cardiovascular events. The pooled relative risk (RR) of all-cause mortality was 2.33 (95% CI 1.88–2.88) and the RR of cardiovascular events was 1.89 (95% CI 1.42, 2.52) comparing the highest with the lowest category of NLR.

Conclusions

The meta-analysis indicates that NLR is a predictor of all-cause mortality and cardiovascular events. Further well-designed trials are warranted to confirm this association.     

Ovine forestomach matrix biomaterial is a broad spectrum inhibitor of matrix metalloproteinases and neutrophil elastase

Proteases play a critical role in the ordered remodelling of extracellular matrix (ECM) components during wound healing and tissue regeneration. However, the usually ordered proteolysis is compromised in chronic wounds due to over‐expression and high concentrations of matrix metalloproteinase's (MMPs) and neutrophil elastase (NE). Ovine forestomach matrix (OFM) is a decellularised extracellular matrix‐based biomaterial developed for tissue regeneration applications, including the treatment of chronic wounds, and is a heterogeneous mixture of ECM proteins and proteoglycans that retains the native structural and functional characteristics of tissue ECM. Given the diverse molecular species present in OFM, we hypothesised that OFM may contain components or fragments that inhibit MMP and NE activity. An extract of OFM was shown to be a potent inhibitor of a range of tissue MMPs (IC₅₀s = 23 ± 5 to 115 ± 14 µg/ml) and NE (IC₅₀ = 157 ± 37 µg/ml), and was more potent than extracts prepared from a known protease modulating wound dressing. The broad spectrum activity of OFM against different classes of MMPs (i.e. collagenases, gelatinases and stromelysins) may provide a clinical advantage by more effectively addressing the protease imbalance seen in chronic wounds.     

Effects of Surgical Stress on Early Nonspecific Immune Response in Children

Surgery alters the body’s homeostatic balance and defense mechanisms. In adults transient postoperative cellular and humoral immunosuppression after different degrees of operative stress has been reported. In children the immunologic consequences of operations are not elaborated. This study investigates the effect of minor and major surgery on early nonspecific immune response in terms of neutrophil counts and function. Forty-three children undergoing minor and major elective procedures were studied. Blood samples were collected before, immediately after, and 72 h after surgery. Total white cell count, differential neutrophil count, and neutrophil phagocytic function were studied using nitroblue tetrazolium test. Children were divided into two groups—group 1 underwent minor surgery and group 2 major surgery. In group 1 there was a significant drop in total counts after surgery, but in group 2 total counts were not affected. In both groups, the percentage of neutrophils increased immediately after surgery but fell to near or less than preoperative levels 72 h after surgery. However, the assessment of neutrophil functions by nitroblue tetrazolium test in both unstimulated and stimulated forms revealed it to be unchanged in group 1. In group 2 the unstimulated neutrophil function was elevated 72 h after surgery, whereas stimulated function was elevated immediately after surgery. Minor surgery does not alter the early nonspecific immune response. However, major surgery seems to induce a transient increase in neutrophil phagocytic activity.     

Neutrophil activation in Alzheimer’s disease and mild cognitive impairment: A systematic review and meta-analysis of protein markers in blood and cerebrospinal fluid

Inflammation is involved in the pathophysiology of Alzheimer’s disease (AD), with multiple inflammatory processes implicated in its risk and progression. This review included original peer-reviewed studies measuring the cerebrospinal fluid or peripheral blood concentrations of protein markers specifically related to neutrophil activity in healthy controls (HC) and in patients with AD or mild cognitive impairment (MCI). A total of 35 studies (N_HC = 3095, N_AD = 2596, N_MCI = 1203) were included. Random-effects meta-analyses were used to estimate between-groups standardized mean differences (SMD) and 95 % confidence intervals. In blood, concentrations of myeloperoxidase (MPO; N_AD/N_HC = 271/209, SMD = 0.41 [0.20, 0.62]; I² = 15.7 %) and neutrophil gelatinase associated lipocalin (NGAL; N_AD/N_HC = 273/185, SMD = 0.30 [0.11, 0.49]; I² < 0.005 %) were significantly higher in AD relative to HC. Peripheral blood concentrations of NGAL were also higher in MCI compared to HC (N_MCI/N_HC = 489/145, SMD = 0.39 [0.11, 0.67]; I² = 38.6 %). None of the protein markers exhibited a significant difference between HC, MCI, or AD groups in the cerebrospinal fluid. The evidence suggests that peripheral neutrophil activation, as indicated by blood concentrations of NGAL and MPO, may be a pathological feature of cognitive impairment due to AD, evident at stages of MCI and AD dementia.     

Diagnostic value of serum neutrophil gelatinase-associated lipocalin,interleukin-6 and anti-citrullinated alpha-enolase peptide 1 for lower respiratory tract infections

ObjectivesThe aim of this study was to explore the auxiliary diagnostic value of neutrophil gelatinase-associated lipocalin (NGAL) and anti-citrullinated alpha-enolase peptide 1 (CEP-1) in lower respiratory tract infections (LRTIs).MethodsBlood samples were collected from 99 in-patients with LRTIs [62 community-acquired pneumonia (CAP), 14 acute exacerbated chronic obstructive pulmonary diseases (AECOPD), 23 other diseases] and 50 healthy subjects. NGAL, CEP-1 and IL-6 were measured and compared. IL-6 was tested by electrochemiluminescence assay kit on Roche E601 immunology analyzer, CEP-1 was assessed with enzyme-linked immunosorbent assay kit, and NGAL was detected by latex immunoturbidimetric assay kit on Beckman Coulter AU2700.ResultsCompared with healthy controls, NGAL and IL-6 levels were significantly increased in the patients with LRTIs, the area under the curves (AUC) was 0.97 and 0.88 respectively (P < 0.01). The sensitivity and specificity of NGAL at a cut-off of 86 ng/ml were 93.0% and 96.0%, respectively, in which the sensitivity was consistent with IL-6 (P = 0.21) and the specificity was better than IL-6 (P < 0.01). CEP-1 slightly increases in the patient group, however the difference was not significant (P = 0.41). The levels of NGAL and IL-6 was no differences in different diseases, the P-value was 0.50 and 0.29, respectively. LRTIs with and without underlying diseases have similar NGAL and IL-6 values.ConclusionsNGAL, rather than CEP-1, may be appealing adjuncts for diagnosis of LRTIs. NGAL proved to be a better biomarker than IL-6.     

抗磷脂抗体和子痫前期的研究进展

抗磷脂抗体是一类能与磷脂或磷脂结合蛋白结合的自身免疫性抗体,与血栓形成、不良孕产史密切相关。抗磷脂抗体中高滴度阳性的患者易有子痫前期等不良妊娠结局。子痫前期发生于妊娠期,可导致全身多脏器的损伤,严重危及母儿生命和健康。子痫前期的发病机制目前还不是很清楚,研究提示抗磷脂抗体可能通过诱导氧化应激,促进血管内炎症等作用参与子痫前期的发病;对于抗磷脂抗体阳性的患者,早期发现和早期干预对获得良好的妊娠结局至关重要。     

西维来司钠对体外循环中红细胞的保护作用

目的研究西维来司钠对体外循环(Cardiopulmonary bypass,CPB)期间红细胞的保护作用。方法健康成年杂种犬12条,随机分为对照组(C组)和西维来司钠组(S组)。两组动物均模拟临床开胸,建立体外循环模型,阻断升主动脉45min后开放,开放后继续转机60min。S组于开胸前静脉推注西维来司钠15mg·kg-1,再以10mg·kg-1·h-持续静脉滴注至体外循环结束。C组用生理盐水对照。分别于转机前、阻断15min、45min、开放30min以及开放60min取静脉血测定血浆弹性蛋白酶(Neutrophil elastase,NE))、丙二醛(Malondialdehyde,MDA)含量、游离血红蛋白浓度(FHB)。结果 S组CPB后各时点血浆NE、MDA含量和FHB浓度低于C组。结论 CPB可导致红细胞的损伤,这种机制与CPB期间大量弹性蛋白酶的产生有关,西维来司钠能有效地抑制CPB期间弹性蛋白酶的产生及其活性,对体外循环期间红细胞有保护作用。     

中性粒细胞凋亡的线粒体死亡机制的研究进展

中性粒细胞是血细胞中寿命最短的终末分化细胞,在炎症反应中发挥着重要的作用,是人体免疫防御系统的第一道防线。与其它的血细胞和组织细胞在凋亡的发生机制上有所不同,中性粒细胞从分化成熟开始,就启动它的自发性凋亡程序。中性粒细胞自发性凋亡涉及到许多复杂的生化过程,线粒体是细胞的一种重要的细胞器,也是真核生物能量代谢的中心、凋亡中心,其在中性粒细胞凋亡信号传导和病理生理过程中起着关键性的调节作用。因此,对线粒体途径的调控机制进行研究是非常重要的。