Characteristics of platelet count and size and diagnostic accuracy of mean platelet volume in patients with venous thromboembolism. A systematic review and meta-analysis.

The purpose of this study was to evaluate the association between platelet (PLT) count and mean platelet volume (MPV) and venous thromboembolism (VTE). Thus, this study reviewed and performed a quantitative synthesis on data from the literature. This meta-analysis was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. 18 studies were included in this paper. A random-effect meta-analysis was conducted for the assessment of heterogeneity using thrombosis place, type of analyzer, type of anticoagulant and incubation time of samples as covariates. A mixed-effect meta-regression was performed based on the subgroup for the whole samples using thrombosis place and method of measurement as moderators for MPV and PLT, respectively. The cumulative estimates and 95% confidence interval (95%CI) of specificity, sensitivity, area under the receiver operator characteristic curve (AUC) and diagnostic odds ratio (DOR) for MPV were calculated using a random effect model. The quality assessments were evaluated according to the quality assessment and diagnostic accuracy tool-2 (QUADAS-2). The primary outcome was the occurrence of VTE. Secondary outcomes included PLT and MPV. Patient with deep vein thrombosis is likely to have a higher value of MPV than control group (P < 0.001). The presence of pulmonary embolism (PE) had no significant effect on the standardized mean difference of MPV between patients and controls. Patients are likely to have less PLT than the control group regarding all studies. However, subgroup analysis demonstrated that this effect was significant for patients with PE (P < 0.05). The summary receiver operating characteristic (SROC) curve indicated that AUC was 0.745 (95% CI: 0.672-0.834). The DOR for MPV was 4.76 (95%CI: 2.3-9.85), with diagnostic accuracy of 0.66.

Vitamin B12 level in peripheral arterial disease.

Hyperhomocysteinemia is considered a risk factor for atherosclerosis. Methyltetrahydrofolate reductase (MTHFR) gene mutation and low level of plasma vitamin B12 and folate could take part in the etiology of peripheral arterial disease (PAD). We examined whether plasma vitamin B12 and folate levels and MTHFR-C677T polymorphism are associated with the risk of PAD. The study comprised 293 patients (107 females, 186 males, mean age of 66 ± SEM0.7 years) and 293 sex-matched control subjects (mean age of 62 ± SEM0.8 years). We also determined plasma lipid profile, hs-CRP, creatinine, vitamin B12, folate and total homocysteine (tHcy) for all patients and controls. Odds ratios were non-significant for different genotypes of MTHFR-C677T polymorphism. There was a significant lower level of vitamin B12 in PAD patients. 43 and 25 % of patient and control populations were in the lowest quartile of vitamin B12 (<188 pmol/L), respectively. Plasma level of vitamin B12 in the lowest quartile significantly increased tHcy level in PAD patients, and it was independent of plasma folate level. Low level of plasma vitamin B12 was independently associated with hyperhomocysteinemia in PAD patients. The prevalence of the MTHFR-C677T mutation was not significantly different in patients with PAD compared with controls.

Validation of reference genes for the determination of platelet transcript level in healthy individuals and in patients with the history of myocardial infarction.

RT-qPCR is the standard method for studying changes in relative transcript level in different experimental and clinical conditions and in different tissues. No validated reference genes have been reported for the normalization of transcript level in platelets. The very low level of platelet RNA and the elimination of leukocyte contamination represented special methodological difficulties. Our aims were to apply a simple technique to separate platelets for transcript level studies, and select the most stable reference genes for platelets from healthy individuals and from patients with the history of myocardial infarction. We developed a simple, straightforward method of platelet separation for RNA isolation. Platelet activation was inhibited by using acid-citrate-dextrose for anticoagulation and by prostaglandin E1. Leukocyte contamination was eliminated by three consecutive centrifugations. Samples prepared by this method were free of leukocytes, showed no inhibition in PCR reaction and no RNA degradation. The assay demands low blood volume, which complies with the requirements of everyday laboratory routine. Seventeen potential reference genes were investigated, but eight of them were excluded during optimization. The stability of the remaining genes, EEF2, EAR, ACTB, GAPDH, ANAPC5, OAZ1, HDGF, GNAS, and CFL1, were determined by four different descriptive statistics. GAPDH, GNAS, and ACTB were shown to be the most stable genes in platelets of healthy individuals, while HDGF, GNAS, and ACTB were the most stable in platelets of patients with the history of myocardial infarction. The results confirm that data normalization needs assessment of appropriate reference genes for a particular sample set.

High Neutrophil-Lymphocyte Ratio and Low Lymphocyte-Monocyte Ratio Combination after Thrombolysis Is a Potential Predictor of Poor Functional Outcome of Acute Ischemic Stroke.

(1) Background: Ischemic stroke is one of the leading causes of death and disability. An inflammatory response is observed in multiple stages of cerebral ischemia, particularly in the acute phase. Recent publications revealed that the neutrophil−lymphocyte ratio (NLR) and lymphocyte−monocyte ratio (LMR) may be used to predict long-term prognosis in acute ischemic stroke (AIS) after thrombolysis. To test whether there is a relationship between the combination of these parameters and long-term prognosis, we analyzed the NLR−LMR combination in AIS patients treated with intravenous recombinant tissue plasminogen activator (rtPA); (2) Methods: The study included 285 adults with a diagnosis of AIS and rtPA treatment within a 4.5 h time window. Blood samples were obtained at admission and 24 h after thrombolysis to calculate pre- and post-thrombolysis NLR and LMR. Clinical data, including NIHSS was registered on admission and day 1. The long-term outcome was defined 90 days post-event by the modified Rankin Scale (mRS). Therapy-associated intracranial hemorrhage (ICH) was classified according to ECASS II. Receiver operating characteristic curve (ROC) analysis was performed to determine optimal cutoffs of NLR and LMR as predictors of therapy outcomes; (3) Results: Patients were stratified by cutoffs of 5.73 for NLR and 2.08 for LMR. The multivariate logistic regression model, including all possible confounders, displayed no significant association between NLR or LMR with 3-months functional prognosis. The combination of high NLR−low LMR vs. low NRL−high LMR as obtained 24 h after thrombolysis was found to be an independent predictor of poor 3-months functional outcome (mRS ≥ 2; OR 3.407, 95% CI 1.449 to 8.011, p = 0.005). The proportion of patients between low NLR−high LMR and high NLR−low LMR groups from admission to day 1 showed no significant change in the good outcome group. On the other hand, in the poor outcome group (mRS ≥ 2), low NLR−high LMR and high NLR−low LMR groups displayed a significant shift in patient proportions from 67% and 21% at admission (p = 0.001) to 36% and 49% at 24 h after thrombolysis (p < 0.001), respectively; (4) Conclusions: Our study demonstrated for the first time that a high NLR−low LMR combination as observed at 24 h after thrombolysis can serve as an independent predictor of 3-months poor outcome in AIS patients. This simple and readily available data may help clinicians to improve the prognostic estimation of patients and may provide guidance in selecting patients for personalized and intensified care post-thrombolysis.

The effect of metoprolol alone and combined metoprolol-felodipin on the digital microcirculation of patients with primary Raynaud's syndrome.

OBJECTIVES: Calcium channel inhibitors have beneficial impact on microcirculation, but beta-blocker effect is controversial. Clinicians still do not agree on beta-blocker combination with other treatments in the management of impaired microcirculation. The aim of the present study was to describe the effects of beta-blocker metoprolol monotherapy and combined with calcium channel inhibitor felodipin on digital microcirculation in primary Raynaud's syndrome. METHODS: We enrolled in this study 46 patients suffering from both hypertension and primary Raynaud's syndrome. Fifteen patients were treated with beta-blocker monotherapy (metoprolol), 13 received combined beta-blocker and calcium channel blocker therapy (felodipin and metoprolol), while 18 patients without any medications served as controls. Measurement of digital microcirculation was carried out with laser Doppler scanner. RESULTS AND CONCLUSIONS: Our investigation concludes that the concurrent administration of beta-blockers with calcium channel inhibitors positively reduces symptoms in patients suffering from Raynaud's syndrome.