Can mean platelet volume predict coronary vasospasm?

An Increase in Mean Platelet Volume/Platelet Count Ratio Is Associated with Vascular Access Failure in Hemodialysis Patients

After stenosis of arteriovenous vascular access in hemodialysis patients, platelets play a crucial role in subsequent thrombus formation, leading to access failure. In a previous study, the mean platelet volume (MPV)/platelet count ratio, but not MPV alone, was shown to be an independent predictor of 4-year mortality after myocardial infarction. However, little is known about the potential influence of MPV/platelet count ratio on vascular access patency in hemodialysis patients. A total of 143 patients undergoing routine hemodialysis were recruited between January 2013 and February 2016. Vascular access failure (VAF) was defined as thrombosis or a decrease of greater than 50% of normal vessel diameter, requiring either surgical revision or percutaneous transluminal angioplasty. Cox proportional hazards model analysis ascertained that the change of MPV/platelet count ratio between baseline and 3 months [Δ(MPV/platelet count ratio)_3mo-baseline] had prognostic value for VAF. Additionally, the changes of MPV/platelet count ratio over time were compared in patients with and without VAF by using linear mixed model analysis. Of the 143 patients, 38 (26.6%) were diagnosed with VAF. During a median follow-up of 26.9 months (interquartile range 13.0–36.0 months), Δ(MPV/platelet count ratio)_3mo-baseline significantly increased in patients with VAF compared to that in patients without VAF [11.6 (6.3–19.0) vs. 0.8 (-1.8–4.0), P< 0.001]. In multivariate analysis, Δ(MPV/platelet ratio count)_3mo-baseline was an independent predictor of VAF, after adjusting for age, sex, diabetes, hypertension, coronary artery disease, cerebrovascular disease, vascular access type, the presence of previous VAF, and antiplatelet drug use (hazard ratio, 1.15; 95% confidence interval, 1.10–1.21; P< 0.001). Moreover, a liner mixed model revealed that there was a significant increase of MPV/platelet count ratio over time in patients with VAF compared to those without VAF (P< 0.001). An increase in MPV/platelet count ratio over time was an independent risk factor for VAF. Therefore, continuous monitoring of the MPV/platelet count ratio may be useful to screen the risk of VAF in patients undergoing routine hemodialysis.

Is there any relationship between mean platelet volume and varicocele?

Mean platelet volume (MPV) is a parameter that is obtained from an automatic haemogram device during routine blood count and measures platelet reactivity. Increased platelet volume has been considered to be a risk factor for vascular diseases. The aim of this study was to evaluate the relationship between the presence of varicocele and the MPV, platelet count (PLT) and platelet distribution width (PDW) values. We included 264 patients with a diagnosis of varicocele in Group 1, and 220 patients with no varicocele in Group 2. The varicocele diagnosis was performed both with physical examination findings and colour Doppler ultrasonography (CDU). Mean platelet volume values were statistically significantly high (P < 0.001) whereas PLT and PDW values were statistically significantly low (P = 0.011), (P = 0.008) in the varicocele group compared with the control group respectively. However, no significant correlation was found between MPV and PDW in patients diagnosed with varicocele and the varicocele grade on examination and spermatic vein diameter on CDU. Mean platelet volume, which is used widely to measure the size of platelets and indicates platelet reactivity, can provide guidance in the investigation of varicocele pathophysiology and the relevant vascular pathologies.

Are platelet volume indices of clinical use? A multidisciplinary review

Platelet size correlates with platelet activity and can be assessed by platelet volume indices (PVI). The PVI, mean platelet volume (MPV), is universally available with routine blood counts by automated hemograms and therefore is an attractive index to study in clinical scenarios. PVI are useful in assessing the etiology of thrombocytopenia. In addition, a normal platelet distribution width in the setting of thrombocytosis is highly suggestive of a reactive etiology. Higher MPV is also associated with the presence of cardiovascular risk factors, chest pain due to acute coronary syndrome, and adverse outcome after acute coronary syndrome. Results from studies evaluating MPV in patients with peripheral artery disease, unprovoked deep vein thrombosis, and pulmonary embolism further advocate a potential role for MPV in identifying patients at high risk of thrombosis. Nevertheless, most of these data come from retrospective studies some of which have small study populations and confounding factors influencing platelet volume. Moreover, the cut-off values derived from these retrospective studies have not been validated prospectively. Despite the potential for clinical utility evident from these studies, the above-mentioned flaws together with technical problems in measuring MPV currently limit its clinical usefulness. Our review provides a perspective on PVI's potential clinical use.

Mean platelet volume as an indicator of disease severity in patients with acute pancreatitis

AIM

Acute pancreatitis (AP) constitutes a systemic inflammatory process which is often accompanied by thrombosis and bleeding disorders. The role of platelets in the pathophysiology of the disease has not been elucidated yet. Mean platelet volume (MPV) is an index of platelet activation and reported to be influenced by inflammation. The objective of the present study is to assess whether platelet volume would be useful in predicting disease severity in AP. Additionally possible relationship of MPV with clinical and radiologic parameters in conjunction with other inflammatory markers during AP was also investigated.

PATIENTS AND METHODS

A total of 144 AP patients (male/female: 87/57), and 40 healthy subjects (male/female: 23/17) were enrolled in this study. Mean platelet volume and inflammatory parameters were measured for all study participants. Modified Glasgow Prognostic Score (mGPS) and the computerized tomography severity index (CTSI) were used as to predict the disease severity in AP patients.

RESULTS

A statistically significant decrease in MPV levels was observed in AP patients (8.06 ± 0.71 fL) compared with healthy controls (8.63 ± 0.62 fL) (P<0.001). According to the mGPS, overall accuracy of MPV in determining severe AP was 72.7% with a sensitivity, specificity, NPV and PPV of 70.6%, 73.9%, 81.9%, and 60 respectively (AUC: 0.762). Overall accuracy of MPV in predicting disease severity according to CTSI was not superior compared with other inflammation markers.

CONCLUSION

The present study demonstrated that MPV is decreased in AP. Assessment of MPV with other inflammatory markers may provide additional information about disease severity in AP.